source: MondoRescue/branches/3.2/mindi-busybox/archival/dpkg.c

/* vi: set sw=4 ts=4: */
/*
 *  mini dpkg implementation for busybox.
 *  this is not meant as a replacement for dpkg
 *
 *  written by glenn mcgrath with the help of others
 *  copyright (c) 2001 by glenn mcgrath
 *
 *  parts of the version comparison code is plucked from the real dpkg
 *  application which is licensed GPLv2 and
 *  copyright (c) 1995 Ian Jackson <ian@chiark.greenend.org.uk>
 *
 *  started life as a busybox implementation of udpkg
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

/*
 * known difference between busybox dpkg and the official dpkg that i don't
 * consider important, its worth keeping a note of differences anyway, just to
 * make it easier to maintain.
 *  - the first value for the confflile: field isnt placed on a new line.
 *  - when installing a package the status: field is placed at the end of the
 *      section, rather than just after the package: field.
 *
 * bugs that need to be fixed
 *  - (unknown, please let me know when you find any)
 *
 */

//usage:#define dpkg_trivial_usage
//usage:       "[-ilCPru] [-F OPT] PACKAGE"
//usage:#define dpkg_full_usage "\n\n"
//usage:       "Install, remove and manage Debian packages\n"
//usage:    IF_LONG_OPTS(
//usage:     "\n    -i,--install    Install the package"
//usage:     "\n    -l,--list   List of installed packages"
//usage:     "\n    --configure Configure an unpackaged package"
//usage:     "\n    -P,--purge  Purge all files of a package"
//usage:     "\n    -r,--remove Remove all but the configuration files for a package"
//usage:     "\n    --unpack    Unpack a package, but don't configure it"
//usage:     "\n    --force-depends Ignore dependency problems"
//usage:     "\n    --force-confnew Overwrite existing config files when installing"
//usage:     "\n    --force-confold Keep old config files when installing"
//usage:    )
//usage:    IF_NOT_LONG_OPTS(
//usage:     "\n    -i      Install the package"
//usage:     "\n    -l      List of installed packages"
//usage:     "\n    -C      Configure an unpackaged package"
//usage:     "\n    -P      Purge all files of a package"
//usage:     "\n    -r      Remove all but the configuration files for a package"
//usage:     "\n    -u      Unpack a package, but don't configure it"
//usage:     "\n    -F depends  Ignore dependency problems"
//usage:     "\n    -F confnew  Overwrite existing config files when installing"
//usage:     "\n    -F confold  Keep old config files when installing"
//usage:    )

#include "libbb.h"
#include <fnmatch.h>
#include "bb_archive.h"

/* note: if you vary hash_prime sizes be aware,
 * 1) tweaking these will have a big effect on how much memory this program uses.
 * 2) for computational efficiency these hash tables should be at least 20%
 *    larger than the maximum number of elements stored in it.
 * 3) all _hash_prime's must be a prime number or chaos is assured, if your looking
 *    for a prime, try http://www.utm.edu/research/primes/lists/small/10000.txt
 * 4) if you go bigger than 15 bits you may get into trouble (untested) as its
 *    sometimes cast to an unsigned, if you go to 16 bit you will overlap
 *    int's and chaos is assured, 16381 is the max prime for 14 bit field
 */

/* NAME_HASH_PRIME, Stores package names and versions,
 * I estimate it should be at least 50% bigger than PACKAGE_HASH_PRIME,
 * as there a lot of duplicate version numbers */
#define NAME_HASH_PRIME 16381

/* PACKAGE_HASH_PRIME, Maximum number of unique packages,
 * It must not be smaller than STATUS_HASH_PRIME,
 * Currently only packages from status_hashtable are stored in here, but in
 * future this may be used to store packages not only from a status file,
 * but an available_hashtable, and even multiple packages files.
 * Package can be stored more than once if they have different versions.
 * e.g. The same package may have different versions in the status file
 *      and available file */
#define PACKAGE_HASH_PRIME 10007
typedef struct edge_s {
    unsigned operator:4; /* was:3 */
    unsigned type:4;
    unsigned name:16; /* was:14 */
    unsigned version:16; /* was:14 */
} edge_t;

typedef struct common_node_s {
    unsigned name:16; /* was:14 */
    unsigned version:16; /* was:14 */
    unsigned num_of_edges:16; /* was:14 */
    edge_t **edge;
} common_node_t;

/* Currently it doesnt store packages that have state-status of not-installed
 * So it only really has to be the size of the maximum number of packages
 * likely to be installed at any one time, so there is a bit of leeway here */
#define STATUS_HASH_PRIME 8191
typedef struct status_node_s {
    unsigned package:16; /* was:14 */       /* has to fit PACKAGE_HASH_PRIME */
    unsigned status:16; /* was:14 */        /* has to fit STATUS_HASH_PRIME */
} status_node_t;


/* Globals */
struct globals {
    char          *name_hashtable[NAME_HASH_PRIME + 1];
    common_node_t *package_hashtable[PACKAGE_HASH_PRIME + 1];
    status_node_t *status_hashtable[STATUS_HASH_PRIME + 1];
};
#define G (*ptr_to_globals)
#define name_hashtable    (G.name_hashtable   )
#define package_hashtable (G.package_hashtable)
#define status_hashtable  (G.status_hashtable )
#define INIT_G() do { \
    SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
} while (0)


/* Even numbers are for 'extras', like ored dependencies or null */
enum edge_type_e {
    EDGE_NULL = 0,
    EDGE_PRE_DEPENDS = 1,
    EDGE_OR_PRE_DEPENDS = 2,
    EDGE_DEPENDS = 3,
    EDGE_OR_DEPENDS = 4,
    EDGE_REPLACES = 5,
    EDGE_PROVIDES = 7,
    EDGE_CONFLICTS = 9,
    EDGE_SUGGESTS = 11,
    EDGE_RECOMMENDS = 13,
    EDGE_ENHANCES = 15
};
enum operator_e {
    VER_NULL = 0,
    VER_EQUAL = 1,
    VER_LESS = 2,
    VER_LESS_EQUAL = 3,
    VER_MORE = 4,
    VER_MORE_EQUAL = 5,
    VER_ANY = 6
};

typedef struct deb_file_s {
    char *control_file;
    char *filename;
    unsigned package:16; /* was:14 */
} deb_file_t;


static void make_hash(const char *key, unsigned *start, unsigned *decrement, const int hash_prime)
{
    unsigned long hash_num = key[0];
    int len = strlen(key);
    int i;

    /* Maybe i should have uses a "proper" hashing algorithm here instead
     * of making one up myself, seems to be working ok though. */
    for (i = 1; i < len; i++) {
        /* shifts the ascii based value and adds it to previous value
         * shift amount is mod 24 because long int is 32 bit and data
         * to be shifted is 8, don't want to shift data to where it has
         * no effect */
        hash_num += (key[i] + key[i-1]) << ((key[i] * i) % 24);
    }
    *start = (unsigned) hash_num % hash_prime;
    *decrement = (unsigned) 1 + (hash_num % (hash_prime - 1));
}

/* this adds the key to the hash table */
static int search_name_hashtable(const char *key)
{
    unsigned probe_address;
    unsigned probe_decrement;

    make_hash(key, &probe_address, &probe_decrement, NAME_HASH_PRIME);
    while (name_hashtable[probe_address] != NULL) {
        if (strcmp(name_hashtable[probe_address], key) == 0) {
            return probe_address;
        }
        probe_address -= probe_decrement;
        if ((int)probe_address < 0) {
            probe_address += NAME_HASH_PRIME;
        }
    }
    name_hashtable[probe_address] = xstrdup(key);
    return probe_address;
}

/* this DOESNT add the key to the hashtable
 * TODO make it consistent with search_name_hashtable
 */
static unsigned search_status_hashtable(const char *key)
{
    unsigned probe_address;
    unsigned probe_decrement;

    make_hash(key, &probe_address, &probe_decrement, STATUS_HASH_PRIME);
    while (status_hashtable[probe_address] != NULL) {
        if (strcmp(key, name_hashtable[package_hashtable[status_hashtable[probe_address]->package]->name]) == 0) {
            break;
        }
        probe_address -= probe_decrement;
        if ((int)probe_address < 0) {
            probe_address += STATUS_HASH_PRIME;
        }
    }
    return probe_address;
}

static int order(char x)
{
    return (x == '~' ? -1
        : x == '\0' ? 0
        : isdigit(x) ? 0
        : isalpha(x) ? x
        : (unsigned char)x + 256
    );
}

/* This code is taken from dpkg and modified slightly to work with busybox */
static int version_compare_part(const char *val, const char *ref)
{
    if (!val) val = "";
    if (!ref) ref = "";

    while (*val || *ref) {
        int first_diff;

        while ((*val && !isdigit(*val)) || (*ref && !isdigit(*ref))) {
            int vc = order(*val);
            int rc = order(*ref);
            if (vc != rc)
                return vc - rc;
            val++;
            ref++;
        }

        while (*val == '0')
            val++;
        while (*ref == '0')
            ref++;

        first_diff = 0;
        while (isdigit(*val) && isdigit(*ref)) {
            if (first_diff == 0)
                first_diff = *val - *ref;
            val++;
            ref++;
        }
        if (isdigit(*val))
            return 1;
        if (isdigit(*ref))
            return -1;
        if (first_diff)
            return first_diff;
    }
    return 0;
}

/* if ver1 < ver2 return -1,
 * if ver1 = ver2 return 0,
 * if ver1 > ver2 return 1,
 */
static int version_compare(const unsigned ver1, const unsigned ver2)
{
    char *ch_ver1 = name_hashtable[ver1];
    char *ch_ver2 = name_hashtable[ver2];
    unsigned epoch1 = 0, epoch2 = 0;
    char *colon;
    char *deb_ver1, *deb_ver2;
    char *upstream_ver1;
    char *upstream_ver2;
    int result;

    /* Compare epoch */
    colon = strchr(ch_ver1, ':');
    if (colon) {
        epoch1 = atoi(ch_ver1);
        ch_ver1 = colon + 1;
    }
    colon = strchr(ch_ver2, ':');
    if (colon) {
        epoch2 = atoi(ch_ver2);
        ch_ver2 = colon + 1;
    }
    if (epoch1 < epoch2) {
        return -1;
    }
    if (epoch1 > epoch2) {
        return 1;
    }

    /* Compare upstream version */
    upstream_ver1 = xstrdup(ch_ver1);
    upstream_ver2 = xstrdup(ch_ver2);

    /* Chop off debian version, and store for later use */
    deb_ver1 = strrchr(upstream_ver1, '-');
    deb_ver2 = strrchr(upstream_ver2, '-');
    if (deb_ver1) {
        *deb_ver1++ = '\0';
    }
    if (deb_ver2) {
        *deb_ver2++ = '\0';
    }
    result = version_compare_part(upstream_ver1, upstream_ver2);
    if (result == 0) {
        /* Compare debian versions */
        result = version_compare_part(deb_ver1, deb_ver2);
    }

    free(upstream_ver1);
    free(upstream_ver2);
    return result;
}

static int test_version(const unsigned version1, const unsigned version2, const unsigned operator)
{
    const int version_result = version_compare(version1, version2);
    switch (operator) {
    case VER_ANY:
        return TRUE;
    case VER_EQUAL:
        return (version_result == 0);
    case VER_LESS:
        return (version_result < 0);
    case VER_LESS_EQUAL:
        return (version_result <= 0);
    case VER_MORE:
        return (version_result > 0);
    case VER_MORE_EQUAL:
        return (version_result >= 0);
    }
    return FALSE;
}

static int search_package_hashtable(const unsigned name, const unsigned version, const unsigned operator)
{
    unsigned probe_address;
    unsigned probe_decrement;

    make_hash(name_hashtable[name], &probe_address, &probe_decrement, PACKAGE_HASH_PRIME);
    while (package_hashtable[probe_address] != NULL) {
        if (package_hashtable[probe_address]->name == name) {
            if (operator == VER_ANY) {
                return probe_address;
            }
            if (test_version(package_hashtable[probe_address]->version, version, operator)) {
                return probe_address;
            }
        }
        probe_address -= probe_decrement;
        if ((int)probe_address < 0) {
            probe_address += PACKAGE_HASH_PRIME;
        }
    }
    return probe_address;
}

/*
 * This function searches through the entire package_hashtable looking
 * for a package which provides "needle". It returns the index into
 * the package_hashtable for the providing package.
 *
 * needle is the index into name_hashtable of the package we are
 * looking for.
 *
 * start_at is the index in the package_hashtable to start looking
 * at. If start_at is -1 then start at the beginning. This is to allow
 * for repeated searches since more than one package might provide
 * needle.
 *
 * FIXME: I don't think this is very efficient, but I thought I'd keep
 * it simple for now until it proves to be a problem.
 */
static int search_for_provides(int needle, int start_at)
{
    int i, j;
    common_node_t *p;
    for (i = start_at + 1; i < PACKAGE_HASH_PRIME; i++) {
        p = package_hashtable[i];
        if (p == NULL)
            continue;
        for (j = 0; j < p->num_of_edges; j++)
            if (p->edge[j]->type == EDGE_PROVIDES && p->edge[j]->name == needle)
                return i;
    }
    return -1;
}

/*
 * Add an edge to a node
 */
static void add_edge_to_node(common_node_t *node, edge_t *edge)
{
    node->edge = xrealloc_vector(node->edge, 2, node->num_of_edges);
    node->edge[node->num_of_edges++] = edge;
}

/*
 * Create one new node and one new edge for every dependency.
 *
 * Dependencies which contain multiple alternatives are represented as
 * an EDGE_OR_PRE_DEPENDS or EDGE_OR_DEPENDS node, followed by a
 * number of EDGE_PRE_DEPENDS or EDGE_DEPENDS nodes. The name field of
 * the OR edge contains the full dependency string while the version
 * field contains the number of EDGE nodes which follow as part of
 * this alternative.
 */
static void add_split_dependencies(common_node_t *parent_node, const char *whole_line, unsigned edge_type)
{
    char *line = xstrdup(whole_line);
    char *line2;
    char *line_ptr1 = NULL;
    char *line_ptr2 = NULL;
    char *field;
    char *field2;
    char *version;
    edge_t *edge;
    edge_t *or_edge;
    int offset_ch;

    field = strtok_r(line, ",", &line_ptr1);
    do {
        /* skip leading spaces */
        field += strspn(field, " ");
        line2 = xstrdup(field);
        field2 = strtok_r(line2, "|", &line_ptr2);
        or_edge = NULL;
        if ((edge_type == EDGE_DEPENDS || edge_type == EDGE_PRE_DEPENDS)
         && (strcmp(field, field2) != 0)
        ) {
            or_edge = xzalloc(sizeof(edge_t));
            or_edge->type = edge_type + 1;
            or_edge->name = search_name_hashtable(field);
            //or_edge->version = 0; // tracks the number of alternatives
            add_edge_to_node(parent_node, or_edge);
        }

        do {
            edge = xmalloc(sizeof(edge_t));
            edge->type = edge_type;

            /* Skip any extra leading spaces */
            field2 += strspn(field2, " ");

            /* Get dependency version info */
            version = strchr(field2, '(');
            if (version == NULL) {
                edge->operator = VER_ANY;
                /* Get the versions hash number, adding it if the number isnt already in there */
                edge->version = search_name_hashtable("ANY");
            } else {
                /* Skip leading ' ' or '(' */
                version += strspn(version, " (");
                /* Calculate length of any operator characters */
                offset_ch = strspn(version, "<=>");
                /* Determine operator */
                if (offset_ch > 0) {
                    if (strncmp(version, "=", offset_ch) == 0) {
                        edge->operator = VER_EQUAL;
                    } else if (strncmp(version, "<<", offset_ch) == 0) {
                        edge->operator = VER_LESS;
                    } else if (strncmp(version, "<=", offset_ch) == 0) {
                        edge->operator = VER_LESS_EQUAL;
                    } else if (strncmp(version, ">>", offset_ch) == 0) {
                        edge->operator = VER_MORE;
                    } else if (strncmp(version, ">=", offset_ch) == 0) {
                        edge->operator = VER_MORE_EQUAL;
                    } else {
                        bb_error_msg_and_die("illegal operator");
                    }
                }
                /* skip to start of version numbers */
                version += offset_ch;
                version += strspn(version, " ");

                /* Truncate version at trailing ' ' or ')' */
                version[strcspn(version, " )")] = '\0';
                /* Get the versions hash number, adding it if the number isnt already in there */
                edge->version = search_name_hashtable(version);
            }

            /* Get the dependency name */
            field2[strcspn(field2, " (")] = '\0';
            edge->name = search_name_hashtable(field2);

            if (or_edge)
                or_edge->version++;

            add_edge_to_node(parent_node, edge);
            field2 = strtok_r(NULL, "|", &line_ptr2);
        } while (field2 != NULL);

        free(line2);
        field = strtok_r(NULL, ",", &line_ptr1);
    } while (field != NULL);

    free(line);
}

static void free_package(common_node_t *node)
{
    unsigned i;
    if (node) {
        for (i = 0; i < node->num_of_edges; i++) {
            free(node->edge[i]);
        }
        free(node->edge);
        free(node);
    }
}

/*
 * Gets the next package field from package_buffer, separated into the field name
 * and field value, it returns the int offset to the first character of the next field
 */
static int read_package_field(const char *package_buffer, char **field_name, char **field_value)
{
    int offset_name_start = 0;
    int offset_name_end = 0;
    int offset_value_start = 0;
    int offset_value_end = 0;
    int offset = 0;
    int next_offset;
    int name_length;
    int value_length;
    int exit_flag = FALSE;

    if (package_buffer == NULL) {
        *field_name = NULL;
        *field_value = NULL;
        return -1;
    }
    while (1) {
        next_offset = offset + 1;
        switch (package_buffer[offset]) {
            case '\0':
                exit_flag = TRUE;
                break;
            case ':':
                if (offset_name_end == 0) {
                    offset_name_end = offset;
                    offset_value_start = next_offset;
                }
                /* TODO: Name might still have trailing spaces if ':' isnt
                 * immediately after name */
                break;
            case '\n':
                /* TODO: The char next_offset may be out of bounds */
                if (package_buffer[next_offset] != ' ') {
                    exit_flag = TRUE;
                    break;
                }
            case '\t':
            case ' ':
                /* increment the value start point if its a just filler */
                if (offset_name_start == offset) {
                    offset_name_start++;
                }
                if (offset_value_start == offset) {
                    offset_value_start++;
                }
                break;
        }
        if (exit_flag) {
            /* Check that the names are valid */
            offset_value_end = offset;
            name_length = offset_name_end - offset_name_start;
            value_length = offset_value_end - offset_value_start;
            if (name_length == 0) {
                break;
            }
            if ((name_length > 0) && (value_length > 0)) {
                break;
            }

            /* If not valid, start fresh with next field */
            exit_flag = FALSE;
            offset_name_start = offset + 1;
            offset_name_end = 0;
            offset_value_start = offset + 1;
            offset_value_end = offset + 1;
            offset++;
        }
        offset++;
    }
    *field_name = NULL;
    if (name_length) {
        *field_name = xstrndup(&package_buffer[offset_name_start], name_length);
    }
    *field_value = NULL;
    if (value_length > 0) {
        *field_value = xstrndup(&package_buffer[offset_value_start], value_length);
    }
    return next_offset;
}

static unsigned fill_package_struct(char *control_buffer)
{
    static const char field_names[] ALIGN1 =
        "Package\0""Version\0"
        "Pre-Depends\0""Depends\0""Replaces\0""Provides\0"
        "Conflicts\0""Suggests\0""Recommends\0""Enhances\0";

    common_node_t *new_node = xzalloc(sizeof(common_node_t));
    char *field_name;
    char *field_value;
    int field_start = 0;
    int num = -1;
    int buffer_length = strlen(control_buffer);

    new_node->version = search_name_hashtable("unknown");
    while (field_start < buffer_length) {
        unsigned field_num;

        field_start += read_package_field(&control_buffer[field_start],
                &field_name, &field_value);

        if (field_name == NULL) {
            goto fill_package_struct_cleanup;
        }

        field_num = index_in_strings(field_names, field_name);
        switch (field_num) {
        case 0: /* Package */
            new_node->name = search_name_hashtable(field_value);
            break;
        case 1: /* Version */
            new_node->version = search_name_hashtable(field_value);
            break;
        case 2: /* Pre-Depends */
            add_split_dependencies(new_node, field_value, EDGE_PRE_DEPENDS);
            break;
        case 3: /* Depends */
            add_split_dependencies(new_node, field_value, EDGE_DEPENDS);
            break;
        case 4: /* Replaces */
            add_split_dependencies(new_node, field_value, EDGE_REPLACES);
            break;
        case 5: /* Provides */
            add_split_dependencies(new_node, field_value, EDGE_PROVIDES);
            break;
        case 6: /* Conflicts */
            add_split_dependencies(new_node, field_value, EDGE_CONFLICTS);
            break;
        case 7: /* Suggests */
            add_split_dependencies(new_node, field_value, EDGE_SUGGESTS);
            break;
        case 8: /* Recommends */
            add_split_dependencies(new_node, field_value, EDGE_RECOMMENDS);
            break;
        case 9: /* Enhances */
            add_split_dependencies(new_node, field_value, EDGE_ENHANCES);
            break;
        }
 fill_package_struct_cleanup:
        free(field_name);
        free(field_value);
    }

    if (new_node->version == search_name_hashtable("unknown")) {
        free_package(new_node);
        return -1;
    }
    num = search_package_hashtable(new_node->name, new_node->version, VER_EQUAL);
    free_package(package_hashtable[num]);
    package_hashtable[num] = new_node;
    return num;
}

/* if num = 1, it returns the want status, 2 returns flag, 3 returns status */
static unsigned get_status(const unsigned status_node, const int num)
{
    char *status_string = name_hashtable[status_hashtable[status_node]->status];
    char *state_sub_string;
    unsigned state_sub_num;
    int len;
    int i;

    /* set tmp_string to point to the start of the word number */
    for (i = 1; i < num; i++) {
        /* skip past a word */
        status_string += strcspn(status_string, " ");
        /* skip past the separating spaces */
        status_string += strspn(status_string, " ");
    }
    len = strcspn(status_string, " \n");
    state_sub_string = xstrndup(status_string, len);
    state_sub_num = search_name_hashtable(state_sub_string);
    free(state_sub_string);
    return state_sub_num;
}

static void set_status(const unsigned status_node_num, const char *new_value, const int position)
{
    const unsigned new_value_num = search_name_hashtable(new_value);
    unsigned want = get_status(status_node_num, 1);
    unsigned flag = get_status(status_node_num, 2);
    unsigned status = get_status(status_node_num, 3);
    char *new_status;

    switch (position) {
        case 1:
            want = new_value_num;
            break;
        case 2:
            flag = new_value_num;
            break;
        case 3:
            status = new_value_num;
            break;
        default:
            bb_error_msg_and_die("DEBUG ONLY: this shouldnt happen");
    }

    new_status = xasprintf("%s %s %s", name_hashtable[want], name_hashtable[flag], name_hashtable[status]);
    status_hashtable[status_node_num]->status = search_name_hashtable(new_status);
    free(new_status);
}

static const char *describe_status(int status_num)
{
    int status_want, status_state;
    if (status_hashtable[status_num] == NULL || status_hashtable[status_num]->status == 0)
        return "is not installed or flagged to be installed";

    status_want = get_status(status_num, 1);
    status_state = get_status(status_num, 3);

    if (status_state == search_name_hashtable("installed")) {
        if (status_want == search_name_hashtable("install"))
            return "is installed";
        if (status_want == search_name_hashtable("deinstall"))
            return "is marked to be removed";
        if (status_want == search_name_hashtable("purge"))
            return "is marked to be purged";
    }
    if (status_want == search_name_hashtable("unknown"))
        return "is in an indeterminate state";
    if (status_want == search_name_hashtable("install"))
        return "is marked to be installed";

    return "is not installed or flagged to be installed";
}

static void index_status_file(const char *filename)
{
    FILE *status_file;
    char *control_buffer;
    char *status_line;
    status_node_t *status_node = NULL;
    unsigned status_num;

    status_file = xfopen_for_read(filename);
    while ((control_buffer = xmalloc_fgetline_str(status_file, "\n\n")) != NULL) {
        const unsigned package_num = fill_package_struct(control_buffer);
        if (package_num != -1) {
            status_node = xmalloc(sizeof(status_node_t));
            /* fill_package_struct doesnt handle the status field */
            status_line = strstr(control_buffer, "Status:");
            if (status_line != NULL) {
                status_line += 7;
                status_line += strspn(status_line, " \n\t");
                status_line = xstrndup(status_line, strcspn(status_line, "\n"));
                status_node->status = search_name_hashtable(status_line);
                free(status_line);
            }
            status_node->package = package_num;
            status_num = search_status_hashtable(name_hashtable[package_hashtable[status_node->package]->name]);
            status_hashtable[status_num] = status_node;
        }
        free(control_buffer);
    }
    fclose(status_file);
}

static void write_buffer_no_status(FILE *new_status_file, const char *control_buffer)
{
    char *name;
    char *value;
    int start = 0;
    while (1) {
        start += read_package_field(&control_buffer[start], &name, &value);
        if (name == NULL) {
            break;
        }
        if (strcmp(name, "Status") != 0) {
            fprintf(new_status_file, "%s: %s\n", name, value);
        }
    }
}

/* This could do with a cleanup */
static void write_status_file(deb_file_t **deb_file)
{
    FILE *old_status_file = xfopen_for_read("/var/lib/dpkg/status");
    FILE *new_status_file = xfopen_for_write("/var/lib/dpkg/status.udeb");
    char *package_name;
    char *status_from_file;
    char *control_buffer = NULL;
    char *tmp_string;
    int status_num;
    int field_start = 0;
    int write_flag;
    int i = 0;

    /* Update previously known packages */
    while ((control_buffer = xmalloc_fgetline_str(old_status_file, "\n\n")) != NULL) {
        tmp_string = strstr(control_buffer, "Package:");
        if (tmp_string == NULL) {
            continue;
        }

        tmp_string += 8;
        tmp_string += strspn(tmp_string, " \n\t");
        package_name = xstrndup(tmp_string, strcspn(tmp_string, "\n"));
        write_flag = FALSE;
        tmp_string = strstr(control_buffer, "Status:");
        if (tmp_string != NULL) {
            /* Separate the status value from the control buffer */
            tmp_string += 7;
            tmp_string += strspn(tmp_string, " \n\t");
            status_from_file = xstrndup(tmp_string, strcspn(tmp_string, "\n"));
        } else {
            status_from_file = NULL;
        }

        /* Find this package in the status hashtable */
        status_num = search_status_hashtable(package_name);
        if (status_hashtable[status_num] != NULL) {
            const char *status_from_hashtable = name_hashtable[status_hashtable[status_num]->status];
            if (strcmp(status_from_file, status_from_hashtable) != 0) {
                /* New status isnt exactly the same as old status */
                const int state_status = get_status(status_num, 3);
                if ((strcmp("installed", name_hashtable[state_status]) == 0)
                 || (strcmp("unpacked", name_hashtable[state_status]) == 0)
                ) {
                    /* We need to add the control file from the package */
                    i = 0;
                    while (deb_file[i] != NULL) {
                        if (strcmp(package_name, name_hashtable[package_hashtable[deb_file[i]->package]->name]) == 0) {
                            /* Write a status file entry with a modified status */
                            /* remove trailing \n's */
                            write_buffer_no_status(new_status_file, deb_file[i]->control_file);
                            set_status(status_num, "ok", 2);
                            fprintf(new_status_file, "Status: %s\n\n",
                                    name_hashtable[status_hashtable[status_num]->status]);
                            write_flag = TRUE;
                            break;
                        }
                        i++;
                    }
                    /* This is temperary, debugging only */
                    if (deb_file[i] == NULL) {
                        bb_error_msg_and_die("ALERT: cannot find a control file, "
                            "your status file may be broken, status may be "
                            "incorrect for %s", package_name);
                    }
                }
                else if (strcmp("not-installed", name_hashtable[state_status]) == 0) {
                    /* Only write the Package, Status, Priority and Section lines */
                    fprintf(new_status_file, "Package: %s\n", package_name);
                    fprintf(new_status_file, "Status: %s\n", status_from_hashtable);

                    while (1) {
                        char *field_name;
                        char *field_value;
                        field_start += read_package_field(&control_buffer[field_start], &field_name, &field_value);
                        if (field_name == NULL) {
                            break;
                        }
                        if ((strcmp(field_name, "Priority") == 0)
                         || (strcmp(field_name, "Section") == 0)
                        ) {
                            fprintf(new_status_file, "%s: %s\n", field_name, field_value);
                        }
                    }
                    write_flag = TRUE;
                    fputs("\n", new_status_file);
                }
                else if (strcmp("config-files", name_hashtable[state_status]) == 0) {
                    /* only change the status line */
                    while (1) {
                        char *field_name;
                        char *field_value;
                        field_start += read_package_field(&control_buffer[field_start], &field_name, &field_value);
                        if (field_name == NULL) {
                            break;
                        }
                        /* Setup start point for next field */
                        if (strcmp(field_name, "Status") == 0) {
                            fprintf(new_status_file, "Status: %s\n", status_from_hashtable);
                        } else {
                            fprintf(new_status_file, "%s: %s\n", field_name, field_value);
                        }
                    }
                    write_flag = TRUE;
                    fputs("\n", new_status_file);
                }
            }
        }
        /* If the package from the status file wasnt handle above, do it now*/
        if (!write_flag) {
            fprintf(new_status_file, "%s\n\n", control_buffer);
        }

        free(status_from_file);
        free(package_name);
        free(control_buffer);
    }

    /* Write any new packages */
    for (i = 0; deb_file[i] != NULL; i++) {
        status_num = search_status_hashtable(name_hashtable[package_hashtable[deb_file[i]->package]->name]);
        if (strcmp("reinstreq", name_hashtable[get_status(status_num, 2)]) == 0) {
            write_buffer_no_status(new_status_file, deb_file[i]->control_file);
            set_status(status_num, "ok", 2);
            fprintf(new_status_file, "Status: %s\n\n", name_hashtable[status_hashtable[status_num]->status]);
        }
    }
    fclose(old_status_file);
    fclose(new_status_file);

    /* Create a separate backfile to dpkg */
    if (rename("/var/lib/dpkg/status", "/var/lib/dpkg/status.udeb.bak") == -1) {
        if (errno != ENOENT)
            bb_error_msg_and_die("can't create backup status file");
        /* Its ok if renaming the status file fails because status
         * file doesnt exist, maybe we are starting from scratch */
        bb_error_msg("no status file found, creating new one");
    }

    xrename("/var/lib/dpkg/status.udeb", "/var/lib/dpkg/status");
}

/* This function returns TRUE if the given package can satisfy a
 * dependency of type depend_type.
 *
 * A pre-depends is satisfied only if a package is already installed,
 * which a regular depends can be satisfied by a package which we want
 * to install.
 */
static int package_satisfies_dependency(int package, int depend_type)
{
    int status_num = search_status_hashtable(name_hashtable[package_hashtable[package]->name]);

    /* status could be unknown if package is a pure virtual
     * provides which cannot satisfy any dependency by itself.
     */
    if (status_hashtable[status_num] == NULL)
        return 0;

    switch (depend_type) {
    case EDGE_PRE_DEPENDS: return get_status(status_num, 3) == search_name_hashtable("installed");
    case EDGE_DEPENDS:     return get_status(status_num, 1) == search_name_hashtable("install");
    }
    return 0;
}

static int check_deps(deb_file_t **deb_file, int deb_start /*, int dep_max_count - ?? */)
{
    int *conflicts = NULL;
    int conflicts_num = 0;
    int i = deb_start;
    int j;

    /* Check for conflicts
     * TODO: TEST if conflicts with other packages to be installed
     *
     * Add install packages and the packages they provide
     * to the list of files to check conflicts for
     */

    /* Create array of package numbers to check against
     * installed package for conflicts*/
    while (deb_file[i] != NULL) {
        const unsigned package_num = deb_file[i]->package;
        conflicts = xrealloc_vector(conflicts, 2, conflicts_num);
        conflicts[conflicts_num] = package_num;
        conflicts_num++;
        /* add provides to conflicts list */
        for (j = 0; j < package_hashtable[package_num]->num_of_edges; j++) {
            if (package_hashtable[package_num]->edge[j]->type == EDGE_PROVIDES) {
                const int conflicts_package_num = search_package_hashtable(
                    package_hashtable[package_num]->edge[j]->name,
                    package_hashtable[package_num]->edge[j]->version,
                    package_hashtable[package_num]->edge[j]->operator);
                if (package_hashtable[conflicts_package_num] == NULL) {
                    /* create a new package */
                    common_node_t *new_node = xzalloc(sizeof(common_node_t));
                    new_node->name = package_hashtable[package_num]->edge[j]->name;
                    new_node->version = package_hashtable[package_num]->edge[j]->version;
                    package_hashtable[conflicts_package_num] = new_node;
                }
                conflicts = xrealloc_vector(conflicts, 2, conflicts_num);
                conflicts[conflicts_num] = conflicts_package_num;
                conflicts_num++;
            }
        }
        i++;
    }

    /* Check conflicts */
    i = 0;
    while (deb_file[i] != NULL) {
        const common_node_t *package_node = package_hashtable[deb_file[i]->package];
        int status_num = 0;
        status_num = search_status_hashtable(name_hashtable[package_node->name]);

        if (get_status(status_num, 3) == search_name_hashtable("installed")) {
            i++;
            continue;
        }

        for (j = 0; j < package_node->num_of_edges; j++) {
            const edge_t *package_edge = package_node->edge[j];

            if (package_edge->type == EDGE_CONFLICTS) {
                const unsigned package_num =
                    search_package_hashtable(package_edge->name,
                                package_edge->version,
                                package_edge->operator);
                int result = 0;
                if (package_hashtable[package_num] != NULL) {
                    status_num = search_status_hashtable(name_hashtable[package_hashtable[package_num]->name]);

                    if (get_status(status_num, 1) == search_name_hashtable("install")) {
                        result = test_version(package_hashtable[deb_file[i]->package]->version,
                            package_edge->version, package_edge->operator);
                    }
                }

                if (result) {
                    bb_error_msg_and_die("package %s conflicts with %s",
                        name_hashtable[package_node->name],
                        name_hashtable[package_edge->name]);
                }
            }
        }
        i++;
    }


    /* Check dependendcies */
    for (i = 0; i < PACKAGE_HASH_PRIME; i++) {
        int status_num = 0;
        int number_of_alternatives = 0;
        const edge_t * root_of_alternatives = NULL;
        const common_node_t *package_node = package_hashtable[i];

        /* If the package node does not exist then this
         * package is a virtual one. In which case there are
         * no dependencies to check.
         */
        if (package_node == NULL) continue;

        status_num = search_status_hashtable(name_hashtable[package_node->name]);

        /* If there is no status then this package is a
         * virtual one provided by something else. In which
         * case there are no dependencies to check.
         */
        if (status_hashtable[status_num] == NULL) continue;

        /* If we don't want this package installed then we may
         * as well ignore it's dependencies.
         */
        if (get_status(status_num, 1) != search_name_hashtable("install")) {
            continue;
        }

        /* This code is tested only for EDGE_DEPENDS, since I
         * have no suitable pre-depends available. There is no
         * reason that it shouldn't work though :-)
         */
        for (j = 0; j < package_node->num_of_edges; j++) {
            const edge_t *package_edge = package_node->edge[j];
            unsigned package_num;

            if (package_edge->type == EDGE_OR_PRE_DEPENDS
             || package_edge->type == EDGE_OR_DEPENDS
            ) {
                /* start an EDGE_OR_ list */
                number_of_alternatives = package_edge->version;
                root_of_alternatives = package_edge;
                continue;
            }
            if (number_of_alternatives == 0) {  /* not in the middle of an EDGE_OR_ list */
                number_of_alternatives = 1;
                root_of_alternatives = NULL;
            }

            package_num = search_package_hashtable(package_edge->name, package_edge->version, package_edge->operator);

            if (package_edge->type == EDGE_PRE_DEPENDS
             || package_edge->type == EDGE_DEPENDS
            ) {
                int result=1;
                status_num = 0;

                /* If we are inside an alternative then check
                 * this edge is the right type.
                 *
                 * EDGE_DEPENDS == OR_DEPENDS -1
                 * EDGE_PRE_DEPENDS == OR_PRE_DEPENDS -1
                 */
                if (root_of_alternatives && package_edge->type != root_of_alternatives->type - 1)
                    bb_error_msg_and_die("fatal error, package dependencies corrupt: %d != %d - 1",
                            package_edge->type, root_of_alternatives->type);

                if (package_hashtable[package_num] != NULL)
                    result = !package_satisfies_dependency(package_num, package_edge->type);

                if (result) { /* check for other package which provide what we are looking for */
                    int provider = -1;

                    while ((provider = search_for_provides(package_edge->name, provider)) > -1) {
                        if (package_hashtable[provider] == NULL) {
                            puts("Have a provider but no package information for it");
                            continue;
                        }
                        result = !package_satisfies_dependency(provider, package_edge->type);

                        if (result == 0)
                            break;
                    }
                }

                /* It must be already installed, or to be installed */
                number_of_alternatives--;
                if (result && number_of_alternatives == 0) {
                    if (root_of_alternatives)
                        bb_error_msg_and_die(
                            "package %s %sdepends on %s, "
                            "which cannot be satisfied",
                            name_hashtable[package_node->name],
                            package_edge->type == EDGE_PRE_DEPENDS ? "pre-" : "",
                            name_hashtable[root_of_alternatives->name]);
                    bb_error_msg_and_die(
                        "package %s %sdepends on %s, which %s\n",
                        name_hashtable[package_node->name],
                        package_edge->type == EDGE_PRE_DEPENDS ? "pre-" : "",
                        name_hashtable[package_edge->name],
                        describe_status(status_num));
                }
                if (result == 0 && number_of_alternatives) {
                    /* we've found a package which
                     * satisfies the dependency,
                     * so skip over the rest of
                     * the alternatives.
                     */
                    j += number_of_alternatives;
                    number_of_alternatives = 0;
                }
            }
        }
    }
    free(conflicts);
    return TRUE;
}

static char **create_list(const char *filename)
{
    FILE *list_stream;
    char **file_list;
    char *line;
    int count;

    /* don't use [xw]fopen here, handle error ourself */
    list_stream = fopen_for_read(filename);
    if (list_stream == NULL) {
        return NULL;
    }

    file_list = NULL;
    count = 0;
    while ((line = xmalloc_fgetline(list_stream)) != NULL) {
        file_list = xrealloc_vector(file_list, 2, count);
        file_list[count++] = line;
        /*file_list[count] = NULL; - xrealloc_vector did it */
    }
    fclose(list_stream);

    return file_list;
}

/* maybe i should try and hook this into remove_file.c somehow */
static int remove_file_array(char **remove_names, char **exclude_names)
{
    struct stat path_stat;
    int remove_flag = 1; /* not removed anything yet */
    int i, j;

    if (remove_names == NULL) {
        return 0;
    }
    for (i = 0; remove_names[i] != NULL; i++) {
        if (exclude_names != NULL) {
            for (j = 0; exclude_names[j] != NULL; j++) {
                if (strcmp(remove_names[i], exclude_names[j]) == 0) {
                    goto skip;
                }
            }
        }
        /* TODO: why we are checking lstat? we can just try rm/rmdir */
        if (lstat(remove_names[i], &path_stat) < 0) {
            continue;
        }
        if (S_ISDIR(path_stat.st_mode)) {
            remove_flag &= rmdir(remove_names[i]); /* 0 if no error */
        } else {
            remove_flag &= unlink(remove_names[i]); /* 0 if no error */
        }
 skip:
        continue;
    }
    return (remove_flag == 0);
}

static void run_package_script_or_die(const char *package_name, const char *script_type)
{
    char *script_path;
    int result;

    script_path = xasprintf("/var/lib/dpkg/info/%s.%s", package_name, script_type);

    /* If the file doesnt exist is isnt fatal */
    result = access(script_path, F_OK) ? EXIT_SUCCESS : system(script_path);
    free(script_path);
    if (result)
        bb_error_msg_and_die("%s failed, exit code %d", script_type, result);
}

/*
The policy manual defines what scripts get called when and with
what arguments. I realize that busybox does not support all of
these scenarios, but it does support some of them; it does not,
however, run them with any parameters in run_package_script_or_die().
Here are the scripts:

preinst install
preinst install <old_version>
preinst upgrade <old_version>
preinst abort_upgrade <new_version>
postinst configure <most_recent_version>
postinst abort-upgade <new_version>
postinst abort-remove
postinst abort-remove in-favour <package> <version>
postinst abort-deconfigure in-favor <failed_install_package> removing <conflicting_package> <version>
prerm remove
prerm upgrade <new_version>
prerm failed-upgrade <old_version>
prerm remove in-favor <package> <new_version>
prerm deconfigure in-favour <package> <version> removing <package> <version>
postrm remove
postrm purge
postrm upgrade <new_version>
postrm failed-upgrade <old_version>
postrm abort-install
postrm abort-install <old_version>
postrm abort-upgrade <old_version>
postrm disappear <overwriter> <version>
*/
static const char *const all_control_files[] = {
    "preinst", "postinst", "prerm", "postrm",
    "list", "md5sums", "shlibs", "conffiles",
    "config", "templates"
};

static char **all_control_list(const char *package_name)
{
    unsigned i = 0;
    char **remove_files;

    /* Create a list of all /var/lib/dpkg/info/<package> files */
    remove_files = xzalloc(sizeof(all_control_files) + sizeof(char*));
    while (i < ARRAY_SIZE(all_control_files)) {
        remove_files[i] = xasprintf("/var/lib/dpkg/info/%s.%s",
                package_name, all_control_files[i]);
        i++;
    }

    return remove_files;
}

static void free_array(char **array)
{
    if (array) {
        unsigned i = 0;
        while (array[i]) {
            free(array[i]);
            i++;
        }
        free(array);
    }
}

/* This function lists information on the installed packages. It loops through
 * the status_hashtable to retrieve the info. This results in smaller code than
 * scanning the status file. The resulting list, however, is unsorted.
 */
static void list_packages(const char *pattern)
{
    int i;

    puts("    Name           Version");
    puts("+++-==============-==============");

    /* go through status hash, dereference package hash and finally strings */
    for (i = 0; i < STATUS_HASH_PRIME+1; i++) {
        if (status_hashtable[i]) {
            const char *stat_str;  /* status string */
            const char *name_str;  /* package name */
            const char *vers_str;  /* version */
            char  s1, s2;          /* status abbreviations */
            int   spccnt;          /* space count */
            int   j;

            stat_str = name_hashtable[status_hashtable[i]->status];
            name_str = name_hashtable[package_hashtable[status_hashtable[i]->package]->name];
            vers_str = name_hashtable[package_hashtable[status_hashtable[i]->package]->version];

            if (pattern && fnmatch(pattern, name_str, 0) != 0)
                continue;

            /* get abbreviation for status field 1 */
            s1 = stat_str[0] == 'i' ? 'i' : 'r';

            /* get abbreviation for status field 2 */
            for (j = 0, spccnt = 0; stat_str[j] && spccnt < 2; j++) {
                if (stat_str[j] == ' ') spccnt++;
            }
            s2 = stat_str[j];

            /* print out the line formatted like Debian dpkg */
            printf("%c%c  %-14s %s\n", s1, s2, name_str, vers_str);
        }
    }
}

static void remove_package(const unsigned package_num, int noisy)
{
    const char *package_name = name_hashtable[package_hashtable[package_num]->name];
    const char *package_version = name_hashtable[package_hashtable[package_num]->version];
    const unsigned status_num = search_status_hashtable(package_name);
    const int package_name_length = strlen(package_name);
    char **remove_files;
    char **exclude_files;
    char list_name[package_name_length + 25];
    char conffile_name[package_name_length + 30];

    if (noisy)
        printf("Removing %s (%s)...\n", package_name, package_version);

    /* Run prerm script */
    run_package_script_or_die(package_name, "prerm");

    /* Create a list of files to remove, and a separate list of those to keep */
    sprintf(list_name, "/var/lib/dpkg/info/%s.%s", package_name, "list");
    remove_files = create_list(list_name);

    sprintf(conffile_name, "/var/lib/dpkg/info/%s.%s", package_name, "conffiles");
    exclude_files = create_list(conffile_name);

    /* Some directories can't be removed straight away, so do multiple passes */
    while (remove_file_array(remove_files, exclude_files))
        continue;
    free_array(exclude_files);
    free_array(remove_files);

    /* Create a list of files in /var/lib/dpkg/info/<package>.* to keep */
    exclude_files = xzalloc(sizeof(exclude_files[0]) * 3);
    exclude_files[0] = xstrdup(conffile_name);
    exclude_files[1] = xasprintf("/var/lib/dpkg/info/%s.%s", package_name, "postrm");

    /* Create a list of all /var/lib/dpkg/info/<package> files */
    remove_files = all_control_list(package_name);

    remove_file_array(remove_files, exclude_files);
    free_array(remove_files);
    free_array(exclude_files);

    /* rename <package>.conffiles to <package>.list
     * The conffiles control file isn't required in Debian packages, so don't
     * error out if it's missing.  */
    rename(conffile_name, list_name);

    /* Change package status */
    set_status(status_num, "config-files", 3);
}

static void purge_package(const unsigned package_num)
{
    const char *package_name = name_hashtable[package_hashtable[package_num]->name];
    const char *package_version = name_hashtable[package_hashtable[package_num]->version];
    const unsigned status_num = search_status_hashtable(package_name);
    char **remove_files;
    char **exclude_files;
    char list_name[strlen(package_name) + 25];

    printf("Purging %s (%s)...\n", package_name, package_version);

    /* Run prerm script */
    run_package_script_or_die(package_name, "prerm");

    /* Create a list of files to remove */
    sprintf(list_name, "/var/lib/dpkg/info/%s.%s", package_name, "list");
    remove_files = create_list(list_name);

    /* Some directories cant be removed straight away, so do multiple passes */
    while (remove_file_array(remove_files, NULL))
        continue;
    free_array(remove_files);

    /* Create a list of all /var/lib/dpkg/info/<package> files */
    remove_files = all_control_list(package_name);

    /* Delete all of them except the postrm script */
    exclude_files = xzalloc(sizeof(exclude_files[0]) * 2);
    exclude_files[0] = xasprintf("/var/lib/dpkg/info/%s.%s", package_name, "postrm");
    remove_file_array(remove_files, exclude_files);
    free_array(exclude_files);

    /* Run and remove postrm script */
    run_package_script_or_die(package_name, "postrm");
    remove_file_array(remove_files, NULL);

    free_array(remove_files);

    /* Change package status */
    set_status(status_num, "not-installed", 3);
}

static archive_handle_t *init_archive_deb_ar(const char *filename)
{
    archive_handle_t *ar_handle;

    /* Setup an ar archive handle that refers to the gzip sub archive */
    ar_handle = init_handle();
    ar_handle->filter = filter_accept_list_reassign;
    ar_handle->src_fd = xopen(filename, O_RDONLY);

    return ar_handle;
}

static void init_archive_deb_control(archive_handle_t *ar_handle)
{
    archive_handle_t *tar_handle;

    /* Setup the tar archive handle */
    tar_handle = init_handle();
    tar_handle->src_fd = ar_handle->src_fd;

    /* We don't care about data.tar.* or debian-binary, just control.tar.* */
#if ENABLE_FEATURE_SEAMLESS_GZ
    llist_add_to(&(ar_handle->accept), (char*)"control.tar.gz");
#endif
#if ENABLE_FEATURE_SEAMLESS_BZ2
    llist_add_to(&(ar_handle->accept), (char*)"control.tar.bz2");
#endif

    /* Assign the tar handle as a subarchive of the ar handle */
    ar_handle->dpkg__sub_archive = tar_handle;
}

static void init_archive_deb_data(archive_handle_t *ar_handle)
{
    archive_handle_t *tar_handle;

    /* Setup the tar archive handle */
    tar_handle = init_handle();
    tar_handle->src_fd = ar_handle->src_fd;

    /* We don't care about control.tar.* or debian-binary, just data.tar.* */
#if ENABLE_FEATURE_SEAMLESS_GZ
    llist_add_to(&(ar_handle->accept), (char*)"data.tar.gz");
#endif
#if ENABLE_FEATURE_SEAMLESS_BZ2
    llist_add_to(&(ar_handle->accept), (char*)"data.tar.bz2");
#endif

    /* Assign the tar handle as a subarchive of the ar handle */
    ar_handle->dpkg__sub_archive = tar_handle;
}

static void FAST_FUNC data_extract_to_buffer(archive_handle_t *archive_handle)
{
    unsigned size = archive_handle->file_header->size;

    archive_handle->dpkg__buffer = xzalloc(size + 1);
    xread(archive_handle->src_fd, archive_handle->dpkg__buffer, size);
}

static char *deb_extract_control_file_to_buffer(archive_handle_t *ar_handle, llist_t *myaccept)
{
    ar_handle->dpkg__sub_archive->action_data = data_extract_to_buffer;
    ar_handle->dpkg__sub_archive->accept = myaccept;
    ar_handle->dpkg__sub_archive->filter = filter_accept_list;

    unpack_ar_archive(ar_handle);
    close(ar_handle->src_fd);

    return ar_handle->dpkg__sub_archive->dpkg__buffer;
}

static void append_control_file_to_llist(const char *package_name, const char *control_name, llist_t **ll)
{
    FILE *fp;
    char *filename, *line;

    filename = xasprintf("/var/lib/dpkg/info/%s.%s", package_name, control_name);
    fp = fopen_for_read(filename);
    free(filename);
    if (fp != NULL) {
        while ((line = xmalloc_fgetline(fp)) != NULL)
            llist_add_to(ll, line);
        fclose(fp);
    }
}

static char FAST_FUNC filter_rename_config(archive_handle_t *archive_handle)
{
    int fd;
    char *name_ptr = archive_handle->file_header->name + 1;

    /* Is this file marked as config file? */
    if (!find_list_entry(archive_handle->accept, name_ptr))
        return EXIT_SUCCESS; /* no */

    fd = open(name_ptr, O_RDONLY);
    if (fd >= 0) {
        md5_ctx_t md5;
        char *md5line, *buf;
        int count;

        /* Calculate MD5 of existing file */
        buf = xmalloc(4096);
        md5_begin(&md5);
        while ((count = safe_read(fd, buf, 4096)) > 0)
            md5_hash(&md5, buf, count);
        md5_end(&md5, buf); /* using buf as result storage */
        close(fd);

        md5line = xmalloc(16 * 2 + 2 + strlen(name_ptr) + 1);
        sprintf(bin2hex(md5line, buf, 16), "  %s", name_ptr);
        free(buf);

        /* Is it changed after install? */
        if (find_list_entry(archive_handle->accept, md5line) == NULL) {
            printf("Warning: Creating %s as %s.dpkg-new\n", name_ptr, name_ptr);
            archive_handle->file_header->name = xasprintf("%s.dpkg-new", archive_handle->file_header->name);
        }
        free(md5line);
    }
    return EXIT_SUCCESS;
}

static void FAST_FUNC data_extract_all_prefix(archive_handle_t *archive_handle)
{
    char *name_ptr = archive_handle->file_header->name;

    /* Skip all leading "/" */
    while (*name_ptr == '/')
        name_ptr++;
    /* Skip all leading "./" and "../" */
    while (name_ptr[0] == '.') {
        if (name_ptr[1] == '.')
            name_ptr++;
        if (name_ptr[1] != '/')
            break;
        name_ptr += 2;
    }

    if (name_ptr[0] != '\0') {
        archive_handle->file_header->name = xasprintf("%s%s", archive_handle->dpkg__buffer, name_ptr);
        data_extract_all(archive_handle);
        if (fnmatch("*.dpkg-new", archive_handle->file_header->name, 0) == 0) {
            /* remove .dpkg-new suffix */
            archive_handle->file_header->name[strlen(archive_handle->file_header->name) - 9] = '\0';
        }
    }
}

enum {
    /* Commands */
    OPT_configure            = (1 << 0),
    OPT_install              = (1 << 1),
    OPT_list_installed       = (1 << 2),
    OPT_purge                = (1 << 3),
    OPT_remove               = (1 << 4),
    OPT_unpack               = (1 << 5),
    OPTMASK_cmd              = (1 << 6) - 1,
    /* Options */
    OPT_force                = (1 << 6),
    OPT_force_ignore_depends = (1 << 7),
    OPT_force_confnew        = (1 << 8),
    OPT_force_confold        = (1 << 9),
};

static void unpack_package(deb_file_t *deb_file)
{
    const char *package_name = name_hashtable[package_hashtable[deb_file->package]->name];
    const unsigned status_num = search_status_hashtable(package_name);
    const unsigned status_package_num = status_hashtable[status_num]->package;
    char *info_prefix;
    char *list_filename;
    archive_handle_t *archive_handle;
    FILE *out_stream;
    llist_t *accept_list;
    llist_t *conffile_list;
    int i;

    /* If existing version, remove it first */
    conffile_list = NULL;
    if (strcmp(name_hashtable[get_status(status_num, 3)], "installed") == 0) {
        /* Package is already installed, remove old version first */
        printf("Preparing to replace %s %s (using %s)...\n", package_name,
            name_hashtable[package_hashtable[status_package_num]->version],
            deb_file->filename);

        /* Read md5sums from old package */
        if (!(option_mask32 & OPT_force_confold))
            append_control_file_to_llist(package_name, "md5sums", &conffile_list);

        remove_package(status_package_num, 0);
    } else {
        printf("Unpacking %s (from %s)...\n", package_name, deb_file->filename);
    }

    /* Extract control.tar.gz to /var/lib/dpkg/info/<package>.filename */
    info_prefix = xasprintf("/var/lib/dpkg/info/%s.%s", package_name, "");
    archive_handle = init_archive_deb_ar(deb_file->filename);
    init_archive_deb_control(archive_handle);

    accept_list = NULL;
    i = 0;
    while (i < ARRAY_SIZE(all_control_files)) {
        char *c = xasprintf("./%s", all_control_files[i]);
        llist_add_to(&accept_list, c);
        i++;
    }
    archive_handle->dpkg__sub_archive->accept = accept_list;
    archive_handle->dpkg__sub_archive->filter = filter_accept_list;
    archive_handle->dpkg__sub_archive->action_data = data_extract_all_prefix;
    archive_handle->dpkg__sub_archive->dpkg__buffer = info_prefix;
    archive_handle->dpkg__sub_archive->ah_flags |= ARCHIVE_UNLINK_OLD;
    unpack_ar_archive(archive_handle);

    /* Run the preinst prior to extracting */
    run_package_script_or_die(package_name, "preinst");

    /* Don't overwrite existing config files */
    if (!(option_mask32 & OPT_force_confnew))
        append_control_file_to_llist(package_name, "conffiles", &conffile_list);

    /* Extract data.tar.gz to the root directory */
    archive_handle = init_archive_deb_ar(deb_file->filename);
    init_archive_deb_data(archive_handle);
    archive_handle->dpkg__sub_archive->accept = conffile_list;
    /* Why ARCHIVE_REMEMBER_NAMES?
     * We want names collected in ->passed list even if conffile_list
     * is NULL (otherwise get_header_tar may optimize name saving out):
     */
    archive_handle->dpkg__sub_archive->ah_flags |= ARCHIVE_REMEMBER_NAMES | ARCHIVE_UNLINK_OLD;
    archive_handle->dpkg__sub_archive->filter = filter_rename_config;
    archive_handle->dpkg__sub_archive->action_data = data_extract_all_prefix;
    archive_handle->dpkg__sub_archive->dpkg__buffer = (char*)"/"; /* huh? */
    unpack_ar_archive(archive_handle);

    /* Create the list file */
    list_filename = xasprintf("/var/lib/dpkg/info/%s.%s", package_name, "list");
    out_stream = xfopen_for_write(list_filename);
    archive_handle->dpkg__sub_archive->passed = llist_rev(archive_handle->dpkg__sub_archive->passed);
    while (archive_handle->dpkg__sub_archive->passed) {
        char *filename = llist_pop(&archive_handle->dpkg__sub_archive->passed);
        /* the leading . has been stripped by data_extract_all_prefix already */
        fprintf(out_stream, "%s\n", filename);
        free(filename);
    }
    fclose(out_stream);

    /* change status */
    set_status(status_num, "install", 1);
    set_status(status_num, "unpacked", 3);

    free(info_prefix);
    free(list_filename);
}

static void configure_package(deb_file_t *deb_file)
{
    const char *package_name = name_hashtable[package_hashtable[deb_file->package]->name];
    const char *package_version = name_hashtable[package_hashtable[deb_file->package]->version];
    const int status_num = search_status_hashtable(package_name);

    printf("Setting up %s (%s)...\n", package_name, package_version);

    /* Run the postinst script */
    /* TODO: handle failure gracefully */
    run_package_script_or_die(package_name, "postinst");

    /* Change status to reflect success */
    set_status(status_num, "install", 1);
    set_status(status_num, "installed", 3);
}

int dpkg_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int dpkg_main(int argc UNUSED_PARAM, char **argv)
{
    deb_file_t **deb_file = NULL;
    status_node_t *status_node;
    char *str_f;
    int opt;
    int package_num;
    int deb_count = 0;
    int state_status;
    int status_num;
    int i;
#if ENABLE_LONG_OPTS
    static const char dpkg_longopts[] ALIGN1 =
// FIXME: we use -C non-compatibly, should be:
// "-C|--audit Check for broken package(s)"
        "configure\0"      No_argument        "C"
        "force\0"          Required_argument  "F"
        "install\0"        No_argument        "i"
        "list\0"           No_argument        "l"
        "purge\0"          No_argument        "P"
        "remove\0"         No_argument        "r"
        "unpack\0"         No_argument        "u"
        "force-depends\0"  No_argument        "\xff"
        "force-confnew\0"  No_argument        "\xfe"
        "force-confold\0"  No_argument        "\xfd"
        ;
#endif

    INIT_G();

    IF_LONG_OPTS(applet_long_options = dpkg_longopts);
    opt = getopt32(argv, "CilPruF:", &str_f);
    argv += optind;
    //if (opt & OPT_configure) ... // -C
    if (opt & OPT_force) { // -F (--force in official dpkg)
        if (strcmp(str_f, "depends") == 0)
            opt |= OPT_force_ignore_depends;
        else if (strcmp(str_f, "confnew") == 0)
            opt |= OPT_force_confnew;
        else if (strcmp(str_f, "confold") == 0)
            opt |= OPT_force_confold;
        else
            bb_show_usage();
        option_mask32 = opt;
    }
    //if (opt & OPT_install) ... // -i
    //if (opt & OPT_list_installed) ... // -l
    //if (opt & OPT_purge) ... // -P
    //if (opt & OPT_remove) ... // -r
    //if (opt & OPT_unpack) ... // -u (--unpack in official dpkg)
    if (!(opt & OPTMASK_cmd) /* no cmd */
     || ((opt & OPTMASK_cmd) & ((opt & OPTMASK_cmd)-1)) /* more than one cmd */
    ) {
        bb_show_usage();
    }

/*  puts("(Reading database ... xxxxx files and directories installed.)"); */
    index_status_file("/var/lib/dpkg/status");

    /* if the list action was given print the installed packages and exit */
    if (opt & OPT_list_installed) {
        list_packages(argv[0]); /* param can be NULL */
        return EXIT_SUCCESS;
    }

    /* Read arguments and store relevant info in structs */
    while (*argv) {
        /* deb_count = nb_elem - 1 and we need nb_elem + 1 to allocate terminal node [NULL pointer] */
        deb_file = xrealloc_vector(deb_file, 2, deb_count);
        deb_file[deb_count] = xzalloc(sizeof(deb_file[0][0]));
        if (opt & (OPT_install | OPT_unpack)) {
            /* -i/-u: require filename */
            archive_handle_t *archive_handle;
            llist_t *control_list = NULL;

            /* Extract the control file */
            llist_add_to(&control_list, (char*)"./control");
            archive_handle = init_archive_deb_ar(argv[0]);
            init_archive_deb_control(archive_handle);
            deb_file[deb_count]->control_file = deb_extract_control_file_to_buffer(archive_handle, control_list);
            if (deb_file[deb_count]->control_file == NULL) {
                bb_error_msg_and_die("can't extract control file");
            }
            deb_file[deb_count]->filename = xstrdup(argv[0]);
            package_num = fill_package_struct(deb_file[deb_count]->control_file);

            if (package_num == -1) {
                bb_error_msg("invalid control file in %s", argv[0]);
                argv++;
                continue;
            }
            deb_file[deb_count]->package = (unsigned) package_num;

            /* Add the package to the status hashtable */
            if (opt & (OPT_unpack | OPT_install)) {
                /* Try and find a currently installed version of this package */
                status_num = search_status_hashtable(name_hashtable[package_hashtable[deb_file[deb_count]->package]->name]);
                /* If no previous entry was found initialise a new entry */
                if (status_hashtable[status_num] == NULL
                 || status_hashtable[status_num]->status == 0
                ) {
                    status_node = xmalloc(sizeof(status_node_t));
                    status_node->package = deb_file[deb_count]->package;
                    /* reinstreq isnt changed to "ok" until the package control info
                     * is written to the status file*/
                    status_node->status = search_name_hashtable("install reinstreq not-installed");
                    status_hashtable[status_num] = status_node;
                } else {
                    set_status(status_num, "install", 1);
                    set_status(status_num, "reinstreq", 2);
                }
            }
        } else if (opt & (OPT_configure | OPT_purge | OPT_remove)) {
            /* -C/-p/-r: require package name */
            deb_file[deb_count]->package = search_package_hashtable(
                    search_name_hashtable(argv[0]),
                    search_name_hashtable("ANY"), VER_ANY);
            if (package_hashtable[deb_file[deb_count]->package] == NULL) {
                bb_error_msg_and_die("package %s is uninstalled or unknown", argv[0]);
            }
            package_num = deb_file[deb_count]->package;
            status_num = search_status_hashtable(name_hashtable[package_hashtable[package_num]->name]);
            state_status = get_status(status_num, 3);

            /* check package status is "installed" */
            if (opt & OPT_remove) {
                if (strcmp(name_hashtable[state_status], "not-installed") == 0
                 || strcmp(name_hashtable[state_status], "config-files") == 0
                ) {
                    bb_error_msg_and_die("%s is already removed", name_hashtable[package_hashtable[package_num]->name]);
                }
                set_status(status_num, "deinstall", 1);
            } else if (opt & OPT_purge) {
                /* if package status is "conf-files" then its ok */
                if (strcmp(name_hashtable[state_status], "not-installed") == 0) {
                    bb_error_msg_and_die("%s is already purged", name_hashtable[package_hashtable[package_num]->name]);
                }
                set_status(status_num, "purge", 1);
            }
        }
        deb_count++;
        argv++;
    }
    if (!deb_count)
        bb_error_msg_and_die("no package files specified");
    deb_file[deb_count] = NULL;

    /* Check that the deb file arguments are installable */
    if (!(opt & OPT_force_ignore_depends)) {
        if (!check_deps(deb_file, 0 /*, deb_count*/)) {
            bb_error_msg_and_die("dependency check failed");
        }
    }

    /* TODO: install or remove packages in the correct dependency order */
    for (i = 0; i < deb_count; i++) {
        /* Remove or purge packages */
        if (opt & OPT_remove) {
            remove_package(deb_file[i]->package, 1);
        }
        else if (opt & OPT_purge) {
            purge_package(deb_file[i]->package);
        }
        else if (opt & OPT_unpack) {
            unpack_package(deb_file[i]);
        }
        else if (opt & OPT_install) {
            unpack_package(deb_file[i]);
            /* package is configured in second pass below */
        }
        else if (opt & OPT_configure) {
            configure_package(deb_file[i]);
        }
    }
    /* configure installed packages */
    if (opt & OPT_install) {
        for (i = 0; i < deb_count; i++)
            configure_package(deb_file[i]);
    }

    write_status_file(deb_file);

    if (ENABLE_FEATURE_CLEAN_UP) {
        for (i = 0; i < deb_count; i++) {
            free(deb_file[i]->control_file);
            free(deb_file[i]->filename);
            free(deb_file[i]);
        }

        free(deb_file);

        for (i = 0; i < NAME_HASH_PRIME; i++) {
            free(name_hashtable[i]);
        }

        for (i = 0; i < PACKAGE_HASH_PRIME; i++) {
            free_package(package_hashtable[i]);
        }

        for (i = 0; i < STATUS_HASH_PRIME; i++) {
            free(status_hashtable[i]);
        }

        free(status_hashtable);
        free(package_hashtable);
        free(name_hashtable);
    }

    return EXIT_SUCCESS;
}