Changeset 1765 in MondoRescue for branches/2.2.5/mindi-busybox/archival/libunarchive/get_header_tar.c

Timestamp:

Nov 4, 2007, 3:16:40 AM (16 years ago)

Author:

Bruno Cornec

Message:

Update to busybox 1.7.2

File:

• branches/2.2.5/mindi-busybox/archival/libunarchive/get_header_tar.c (modified) (4 diffs)

branches/2.2.5/mindi-busybox/archival/libunarchive/get_header_tar.c

@@ +1 @@
+/* vi: set sw=4 ts=4: */
 /* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  *
@@ -11 +12 @@
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/sysmacros.h>  /* For makedev */
+#include "libbb.h"
 #include "unarchive.h"
-#include "libbb.h"
-
-#ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
-static char *longname = NULL;
-static char *linkname = NULL;
-#endif
-
+
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+static char *longname;
+static char *linkname;
+#else
+enum {
+    longname = 0,
+    linkname = 0,
+};
+#endif
+
+/* NB: _DESTROYS_ str[len] character! */
+static unsigned long long getOctal(char *str, int len)
+{
+    unsigned long long v;
+    /* Actually, tar header allows leading spaces also.
+     * Oh well, we will be liberal and skip this...
+     * The only downside probably is that we allow "-123" too :)
+    if (*str < '0' || *str > '7')
+        bb_error_msg_and_die("corrupted octal value in tar header");
+    */
+    str[len] = '\0';
+    v = strtoull(str, &str, 8);
+    if (*str && (!ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY || *str != ' '))
+        bb_error_msg_and_die("corrupted octal value in tar header");
+    return v;
+}
+#define GET_OCTAL(a) getOctal((a), sizeof(a))
+
+void BUG_tar_header_size(void);
 char get_header_tar(archive_handle_t *archive_handle)
 {
+    static smallint end;
+
     file_header_t *file_header = archive_handle->file_header;
-    union {
+    struct {
         /* ustar header, Posix 1003.1 */
-        unsigned char raw[512];
-        struct {
-            char name[100]; /*   0-99 */
-            char mode[8];   /* 100-107 */
-            char uid[8];    /* 108-115 */
-            char gid[8];    /* 116-123 */
-            char size[12];  /* 124-135 */
-            char mtime[12]; /* 136-147 */
-            char chksum[8]; /* 148-155 */
-            char typeflag;  /* 156-156 */
-            char linkname[100]; /* 157-256 */
-            char magic[6];  /* 257-262 */
-            char version[2];    /* 263-264 */
-            char uname[32]; /* 265-296 */
-            char gname[32]; /* 297-328 */
-            char devmajor[8];   /* 329-336 */
-            char devminor[8];   /* 337-344 */
-            char prefix[155];   /* 345-499 */
-            char padding[12];   /* 500-512 */
-        } formated;
+        char name[100];     /*   0-99 */
+        char mode[8];       /* 100-107 */
+        char uid[8];        /* 108-115 */
+        char gid[8];        /* 116-123 */
+        char size[12];      /* 124-135 */
+        char mtime[12];     /* 136-147 */
+        char chksum[8];     /* 148-155 */
+        char typeflag;      /* 156-156 */
+        char linkname[100]; /* 157-256 */
+        char magic[6];      /* 257-262 */
+        char version[2];    /* 263-264 */
+        char uname[32];     /* 265-296 */
+        char gname[32];     /* 297-328 */
+        char devmajor[8];   /* 329-336 */
+        char devminor[8];   /* 337-344 */
+        char prefix[155];   /* 345-499 */
+        char padding[12];   /* 500-512 */
     } tar;
-    long sum = 0;
-    long i;
-    static int end = 0;
-
+    char *cp;
+    int i, sum_u, sum;
+#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY
+    int sum_s;
+#endif
+    int parse_names;
+
+    if (sizeof(tar) != 512)
+        BUG_tar_header_size();
+
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+ again:
+#endif
     /* Align header */
     data_align(archive_handle, 512);
 
-    if (bb_full_read(archive_handle->src_fd, tar.raw, 512) != 512) {
-        /* Assume end of file */
-        bb_error_msg_and_die("Short header");
-        //return(EXIT_FAILURE);
-    }
+ again_after_align:
+
+    xread(archive_handle->src_fd, &tar, 512);
     archive_handle->offset += 512;
 
     /* If there is no filename its an empty header */
-    if (tar.formated.name[0] == 0) {
+    if (tar.name[0] == 0) {
         if (end) {
             /* This is the second consecutive empty header! End of archive!
              * Read until the end to empty the pipe from gz or bz2
              */
-            while (bb_full_read(archive_handle->src_fd, tar.raw, 512) == 512);
-            return(EXIT_FAILURE);
+            while (full_read(archive_handle->src_fd, &tar, 512) == 512)
+                /* repeat */;
+            return EXIT_FAILURE;
         }
         end = 1;
-        return(EXIT_SUCCESS);
+        return EXIT_SUCCESS;
     }
     end = 0;
@@ -80 +108 @@
      * 0's are for the old tar format
      */
-    if (strncmp(tar.formated.magic, "ustar", 5) != 0) {
-#ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATIBILITY
-        if (strncmp(tar.formated.magic, "\0\0\0\0\0", 5) != 0)
-#endif
-            bb_error_msg_and_die("Invalid tar magic");
-    }
-    /* Do checksum on headers */
-    for (i =  0; i < 148 ; i++) {
-        sum += tar.raw[i];
-    }
-    sum += ' ' * 8;
-    for (i =  156; i < 512 ; i++) {
-        sum += tar.raw[i];
-    }
-    if (sum != strtol(tar.formated.chksum, NULL, 8)) {
-        bb_error_msg("Invalid tar header checksum");
-        return(EXIT_FAILURE);
-    }
-
-#ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
+    if (strncmp(tar.magic, "ustar", 5) != 0) {
+#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
+        if (memcmp(tar.magic, "\0\0\0\0", 5) != 0)
+#endif
+            bb_error_msg_and_die("invalid tar magic");
+    }
+
+    /* Do checksum on headers.
+     * POSIX says that checksum is done on unsigned bytes, but
+     * Sun and HP-UX gets it wrong... more details in
+     * GNU tar source. */
+#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY
+    sum_s = ' ' * sizeof(tar.chksum);
+#endif
+    sum_u = ' ' * sizeof(tar.chksum);
+    for (i = 0; i < 148; i++) {
+        sum_u += ((unsigned char*)&tar)[i];
+#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY
+        sum_s += ((signed char*)&tar)[i];
+#endif
+    }
+    for (i = 156; i < 512; i++) {
+        sum_u += ((unsigned char*)&tar)[i];
+#if ENABLE_FEATURE_TAR_OLDSUN_COMPATIBILITY
+        sum_s += ((signed char*)&tar)[i];
+#endif
+    }
+#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
+    sum = strtoul(tar.chksum, &cp, 8);
+    if ((*cp && *cp != ' ')
+     || (sum_u != sum USE_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum))
+    ) {
+        bb_error_msg_and_die("invalid tar header checksum");
+    }
+#else
+    /* This field does not need special treatment (getOctal) */
+    sum = xstrtoul(tar.chksum, 8);
+    if (sum_u != sum USE_FEATURE_TAR_OLDSUN_COMPATIBILITY(&& sum_s != sum)) {
+        bb_error_msg_and_die("invalid tar header checksum");
+    }
+#endif
+
+    /* 0 is reserved for high perf file, treat as normal file */
+    if (!tar.typeflag) tar.typeflag = '0';
+    parse_names = (tar.typeflag >= '0' && tar.typeflag <= '7');
+
+    /* getOctal trashes subsequent field, therefore we call it
+     * on fields in reverse order */
+    if (tar.devmajor[0]) {
+        unsigned minor = GET_OCTAL(tar.devminor);
+        unsigned major = GET_OCTAL(tar.devmajor);
+        file_header->device = makedev(major, minor);
+    }
+    file_header->link_target = NULL;
+    if (!linkname && parse_names && tar.linkname[0]) {
+        /* we trash magic[0] here, it's ok */
+        tar.linkname[sizeof(tar.linkname)] = '\0';
+        file_header->link_target = xstrdup(tar.linkname);
+        /* FIXME: what if we have non-link object with link_target? */
+        /* Will link_target be free()ed? */
+    }
+    file_header->mtime = GET_OCTAL(tar.mtime);
+    file_header->size = GET_OCTAL(tar.size);
+    file_header->gid = GET_OCTAL(tar.gid);
+    file_header->uid = GET_OCTAL(tar.uid);
+    /* Set bits 0-11 of the files mode */
+    file_header->mode = 07777 & GET_OCTAL(tar.mode);
+
+    file_header->name = NULL;
+    if (!longname && parse_names) {
+        /* we trash mode[0] here, it's ok */
+        tar.name[sizeof(tar.name)] = '\0';
+        if (tar.prefix[0]) {
+            /* and padding[0] */
+            tar.prefix[sizeof(tar.prefix)] = '\0';
+            file_header->name = concat_path_file(tar.prefix, tar.name);
+        } else
+            file_header->name = xstrdup(tar.name);
+    }
+
+    /* Set bits 12-15 of the files mode */
+    /* (typeflag was not trashed because chksum does not use getOctal) */
+    switch (tar.typeflag) {
+    /* busybox identifies hard links as being regular files with 0 size and a link name */
+    case '1':
+        file_header->mode |= S_IFREG;
+        break;
+    case '7':
+    /* case 0: */
+    case '0':
+#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
+        if (last_char_is(file_header->name, '/')) {
+            file_header->mode |= S_IFDIR;
+        } else
+#endif
+        file_header->mode |= S_IFREG;
+        break;
+    case '2':
+        file_header->mode |= S_IFLNK;
+        break;
+    case '3':
+        file_header->mode |= S_IFCHR;
+        break;
+    case '4':
+        file_header->mode |= S_IFBLK;
+        break;
+    case '5':
+        file_header->mode |= S_IFDIR;
+        break;
+    case '6':
+        file_header->mode |= S_IFIFO;
+        break;
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+    case 'L':
+        /* free: paranoia: tar with several consecutive longnames */
+        free(longname);
+        /* For paranoia reasons we allocate extra NUL char */
+        longname = xzalloc(file_header->size + 1);
+        /* We read ASCIZ string, including NUL */
+        xread(archive_handle->src_fd, longname, file_header->size);
+        archive_handle->offset += file_header->size;
+        /* return get_header_tar(archive_handle); */
+        /* gcc 4.1.1 didn't optimize it into jump */
+        /* so we will do it ourself, this also saves stack */
+        goto again;
+    case 'K':
+        free(linkname);
+        linkname = xzalloc(file_header->size + 1);
+        xread(archive_handle->src_fd, linkname, file_header->size);
+        archive_handle->offset += file_header->size;
+        /* return get_header_tar(archive_handle); */
+        goto again;
+    case 'D':   /* GNU dump dir */
+    case 'M':   /* Continuation of multi volume archive */
+    case 'N':   /* Old GNU for names > 100 characters */
+    case 'S':   /* Sparse file */
+    case 'V':   /* Volume header */
+#endif
+    case 'g':   /* pax global header */
+    case 'x': { /* pax extended header */
+        off_t sz;
+        bb_error_msg("warning: skipping header '%c'", tar.typeflag);
+        sz = (file_header->size + 511) & ~(off_t)511;
+        archive_handle->offset += sz;
+        sz >>= 9; /* sz /= 512 but w/o contortions for signed div */
+        while (sz--)
+            xread(archive_handle->src_fd, &tar, 512);
+        /* return get_header_tar(archive_handle); */
+        goto again_after_align;
+    }
+    default:
+        bb_error_msg_and_die("unknown typeflag: 0x%x", tar.typeflag);
+    }
+
+#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
     if (longname) {
         file_header->name = longname;
         longname = NULL;
     }
-    else if (linkname) {
-        file_header->name = linkname;
+    if (linkname) {
+        file_header->link_target = linkname;
         linkname = NULL;
-    } else
-#endif
-    {
-        file_header->name = bb_xstrndup(tar.formated.name,100);
-
-        if (tar.formated.prefix[0]) {
-            char *temp = file_header->name;
-            file_header->name = concat_path_file(tar.formated.prefix, temp);
-            free(temp);
-        }
-    }
-
-    file_header->uid = strtol(tar.formated.uid, NULL, 8);
-    file_header->gid = strtol(tar.formated.gid, NULL, 8);
-    file_header->size = strtol(tar.formated.size, NULL, 8);
-    file_header->mtime = strtol(tar.formated.mtime, NULL, 8);
-    file_header->link_name = (tar.formated.linkname[0] != '\0') ?
-        bb_xstrdup(tar.formated.linkname) : NULL;
-    file_header->device = makedev(strtol(tar.formated.devmajor, NULL, 8),
-        strtol(tar.formated.devminor, NULL, 8));
-
-    /* Set bits 0-11 of the files mode */
-    file_header->mode = 07777 & strtol(tar.formated.mode, NULL, 8);
-
-    /* Set bits 12-15 of the files mode */
-    switch (tar.formated.typeflag) {
-    /* busybox identifies hard links as being regular files with 0 size and a link name */
-    case '1':
-        file_header->mode |= S_IFREG;
-        break;
-    case '7':
-        /* Reserved for high performance files, treat as normal file */
-    case 0:
-    case '0':
-#ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATIBILITY
-        if (last_char_is(file_header->name, '/')) {
-            file_header->mode |= S_IFDIR;
-        } else
-#endif
-            file_header->mode |= S_IFREG;
-        break;
-    case '2':
-        file_header->mode |= S_IFLNK;
-        break;
-    case '3':
-        file_header->mode |= S_IFCHR;
-        break;
-    case '4':
-        file_header->mode |= S_IFBLK;
-        break;
-    case '5':
-        file_header->mode |= S_IFDIR;
-        break;
-    case '6':
-        file_header->mode |= S_IFIFO;
-        break;
-#ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
-    case 'L': {
-            longname = xzalloc(file_header->size + 1);
-            archive_xread_all(archive_handle, longname, file_header->size);
-            archive_handle->offset += file_header->size;
-
-            return(get_header_tar(archive_handle));
-        }
-    case 'K': {
-            linkname = xzalloc(file_header->size + 1);
-            archive_xread_all(archive_handle, linkname, file_header->size);
-            archive_handle->offset += file_header->size;
-
-            file_header->name = linkname;
-            return(get_header_tar(archive_handle));
-        }
-    case 'D':   /* GNU dump dir */
-    case 'M':   /* Continuation of multi volume archive*/
-    case 'N':   /* Old GNU for names > 100 characters */
-    case 'S':   /* Sparse file */
-    case 'V':   /* Volume header */
-#endif
-    case 'g':   /* pax global header */
-    case 'x':   /* pax extended header */
-        bb_error_msg("Ignoring extension type %c", tar.formated.typeflag);
-        break;
-    default:
-        bb_error_msg("Unknown typeflag: 0x%x", tar.formated.typeflag);
-    }
-    {   /* Strip trailing '/' in directories */
-        /* Must be done after mode is set as '/' is used to check if its a directory */
-        char *tmp = last_char_is(file_header->name, '/');
-        if (tmp) {
-            *tmp = '\0';
-        }
-    }
+    }
+#endif
+    if (!strncmp(file_header->name, "/../"+1, 3)
+     || strstr(file_header->name, "/../")
+    ) {
+        bb_error_msg_and_die("name with '..' encountered: '%s'",
+                file_header->name);
+    }
+
+    /* Strip trailing '/' in directories */
+    /* Must be done after mode is set as '/' is used to check if it's a directory */
+    cp = last_char_is(file_header->name, '/');
 
     if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
         archive_handle->action_header(archive_handle->file_header);
+        /* Note that we kill the '/' only after action_header() */
+        /* (like GNU tar 1.15.1: verbose mode outputs "dir/dir/") */
+        if (cp) *cp = '\0';
         archive_handle->flags |= ARCHIVE_EXTRACT_QUIET;
         archive_handle->action_data(archive_handle);
@@ -207 +293 @@
     } else {
         data_skip(archive_handle);
+        free(file_header->name);
     }
     archive_handle->offset += file_header->size;
 
-    free(file_header->link_name);
-
-    return(EXIT_SUCCESS);
+    free(file_header->link_target);
+    /* Do not free(file_header->name)! */
+
+    return EXIT_SUCCESS;
 }