source: MondoRescue/branches/3.2/mindi-busybox/libbb/inet_common.c@ 3232

/* vi: set sw=4 ts=4: */
/*
 * stolen from net-tools-1.59 and stripped down for busybox by
 *                      Erik Andersen <andersen@codepoet.org>
 *
 * Heavily modified by Manuel Novoa III       Mar 12, 2001
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */

#include "libbb.h"
#include "inet_common.h"

int FAST_FUNC INET_resolve(const char *name, struct sockaddr_in *s_in, int hostfirst)
{
    struct hostent *hp;
#if ENABLE_FEATURE_ETC_NETWORKS
    struct netent *np;
#endif

    /* Grmpf. -FvK */
    s_in->sin_family = AF_INET;
    s_in->sin_port = 0;

    /* Default is special, meaning 0.0.0.0. */
    if (strcmp(name, "default") == 0) {
        s_in->sin_addr.s_addr = INADDR_ANY;
        return 1;
    }
    /* Look to see if it's a dotted quad. */
    if (inet_aton(name, &s_in->sin_addr)) {
        return 0;
    }
    /* If we expect this to be a hostname, try hostname database first */
#ifdef DEBUG
    if (hostfirst) {
        bb_error_msg("gethostbyname(%s)", name);
    }
#endif
    if (hostfirst) {
        hp = gethostbyname(name);
        if (hp != NULL) {
            memcpy(&s_in->sin_addr, hp->h_addr_list[0],
                sizeof(struct in_addr));
            return 0;
        }
    }
#if ENABLE_FEATURE_ETC_NETWORKS
    /* Try the NETWORKS database to see if this is a known network. */
#ifdef DEBUG
    bb_error_msg("getnetbyname(%s)", name);
#endif
    np = getnetbyname(name);
    if (np != NULL) {
        s_in->sin_addr.s_addr = htonl(np->n_net);
        return 1;
    }
#endif
    if (hostfirst) {
        /* Don't try again */
        return -1;
    }
#ifdef DEBUG
    res_init();
    _res.options |= RES_DEBUG;
    bb_error_msg("gethostbyname(%s)", name);
#endif
    hp = gethostbyname(name);
    if (hp == NULL) {
        return -1;
    }
    memcpy(&s_in->sin_addr, hp->h_addr_list[0], sizeof(struct in_addr));
    return 0;
}


/* numeric: & 0x8000: default instead of *,
 *          & 0x4000: host instead of net,
 *          & 0x0fff: don't resolve
 */
char* FAST_FUNC INET_rresolve(struct sockaddr_in *s_in, int numeric, uint32_t netmask)
{
    /* addr-to-name cache */
    struct addr {
        struct addr *next;
        struct sockaddr_in addr;
        int host;
        char name[1];
    };
    static struct addr *cache = NULL;

    struct addr *pn;
    char *name;
    uint32_t ad, host_ad;
    int host = 0;

    if (s_in->sin_family != AF_INET) {
#ifdef DEBUG
        bb_error_msg("rresolve: unsupported address family %d!",
                s_in->sin_family);
#endif
        errno = EAFNOSUPPORT;
        return NULL;
    }
    ad = s_in->sin_addr.s_addr;
#ifdef DEBUG
    bb_error_msg("rresolve: %08x, mask %08x, num %08x", (unsigned)ad, netmask, numeric);
#endif
    if (ad == INADDR_ANY) {
        if ((numeric & 0x0FFF) == 0) {
            if (numeric & 0x8000)
                return xstrdup("default");
            return xstrdup("*");
        }
    }
    if (numeric & 0x0FFF)
        return xstrdup(inet_ntoa(s_in->sin_addr));

    if ((ad & (~netmask)) != 0 || (numeric & 0x4000))
        host = 1;
    pn = cache;
    while (pn) {
        if (pn->addr.sin_addr.s_addr == ad && pn->host == host) {
#ifdef DEBUG
            bb_error_msg("rresolve: found %s %08x in cache",
                      (host ? "host" : "net"), (unsigned)ad);
#endif
            return xstrdup(pn->name);
        }
        pn = pn->next;
    }

    host_ad = ntohl(ad);
    name = NULL;
    if (host) {
        struct hostent *ent;
#ifdef DEBUG
        bb_error_msg("gethostbyaddr (%08x)", (unsigned)ad);
#endif
        ent = gethostbyaddr((char *) &ad, 4, AF_INET);
        if (ent)
            name = xstrdup(ent->h_name);
    } else if (ENABLE_FEATURE_ETC_NETWORKS) {
        struct netent *np;
#ifdef DEBUG
        bb_error_msg("getnetbyaddr (%08x)", (unsigned)host_ad);
#endif
        np = getnetbyaddr(host_ad, AF_INET);
        if (np)
            name = xstrdup(np->n_name);
    }
    if (!name)
        name = xstrdup(inet_ntoa(s_in->sin_addr));
    pn = xmalloc(sizeof(*pn) + strlen(name)); /* no '+ 1', it's already accounted for */
    pn->next = cache;
    pn->addr = *s_in;
    pn->host = host;
    strcpy(pn->name, name);
    cache = pn;
    return name;
}

#if ENABLE_FEATURE_IPV6

int FAST_FUNC INET6_resolve(const char *name, struct sockaddr_in6 *sin6)
{
    struct addrinfo req, *ai = NULL;
    int s;

    memset(&req, 0, sizeof(req));
    req.ai_family = AF_INET6;
    s = getaddrinfo(name, NULL, &req, &ai);
    if (s != 0) {
        bb_error_msg("getaddrinfo: %s: %d", name, s);
        return -1;
    }
    memcpy(sin6, ai->ai_addr, sizeof(*sin6));
    if (ai)
        freeaddrinfo(ai);
    return 0;
}

#ifndef IN6_IS_ADDR_UNSPECIFIED
# define IN6_IS_ADDR_UNSPECIFIED(a) \
    (((uint32_t *) (a))[0] == 0 && ((uint32_t *) (a))[1] == 0 && \
     ((uint32_t *) (a))[2] == 0 && ((uint32_t *) (a))[3] == 0)
#endif


char* FAST_FUNC INET6_rresolve(struct sockaddr_in6 *sin6, int numeric)
{
    char name[128];
    int s;

    if (sin6->sin6_family != AF_INET6) {
#ifdef DEBUG
        bb_error_msg("rresolve: unsupported address family %d!",
                sin6->sin6_family);
#endif
        errno = EAFNOSUPPORT;
        return NULL;
    }
    if (numeric & 0x7FFF) {
        inet_ntop(AF_INET6, &sin6->sin6_addr, name, sizeof(name));
        return xstrdup(name);
    }
    if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
        if (numeric & 0x8000)
            return xstrdup("default");
        return xstrdup("*");
    }

    s = getnameinfo((struct sockaddr *) sin6, sizeof(*sin6),
                name, sizeof(name),
                /*serv,servlen:*/ NULL, 0,
                0);
    if (s != 0) {
        bb_error_msg("getnameinfo failed");
        return NULL;
    }
    return xstrdup(name);
}

#endif  /* CONFIG_FEATURE_IPV6 */