/* 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"

#if 0
# define dbg(...) bb_error_msg(__VA_ARGS__)
#else
# define dbg(...) ((void)0)
#endif

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 */
        if (hostfirst) {
                dbg("gethostbyname(%s)", name);
                hp = gethostbyname(name);
                if (hp) {
                        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. */
        dbg("getnetbyname(%s)", name);
        np = getnetbyname(name);
        if (np) {
                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;
#endif
        dbg("gethostbyname(%s)", name);
        hp = gethostbyname(name);
        if (!hp) {
                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;
                uint32_t nip;
                smallint is_host;
                char name[1];
        };
        static struct addr *cache = NULL;

        struct addr *pn;
        char *name;
        uint32_t nip;
        smallint is_host;

        if (s_in->sin_family != AF_INET) {
                dbg("rresolve: unsupported address family %d!", s_in->sin_family);
                errno = EAFNOSUPPORT;
                return NULL;
        }
        nip = s_in->sin_addr.s_addr;
        dbg("rresolve: %08x mask:%08x num:%08x", (unsigned)nip, netmask, numeric);
        if (numeric & 0x0FFF)
                return xmalloc_sockaddr2dotted_noport((void*)s_in);
        if (nip == INADDR_ANY) {
                if (numeric & 0x8000)
                        return xstrdup("default");
                return xstrdup("*");
        }

        is_host = ((nip & (~netmask)) != 0 || (numeric & 0x4000));

        pn = cache;
        while (pn) {
                if (pn->nip == nip && pn->is_host == is_host) {
                        dbg("rresolve: found %s %08x in cache",
                                (is_host ? "host" : "net"), (unsigned)nip);
                        return xstrdup(pn->name);
                }
                pn = pn->next;
        }

        name = NULL;
        if (is_host) {
                dbg("sockaddr2host_noport(%08x)", (unsigned)nip);
                name = xmalloc_sockaddr2host_noport((void*)s_in);
        }
#if ENABLE_FEATURE_ETC_NETWORKS
        else {
                struct netent *np;
                dbg("getnetbyaddr(%08x)", (unsigned)ntohl(nip));
                np = getnetbyaddr(ntohl(nip), AF_INET);
                if (np)
                        name = xstrdup(np->n_name);
        }
#endif
        if (!name)
                name = xmalloc_sockaddr2dotted_noport((void*)s_in);

        pn = xmalloc(sizeof(*pn) + strlen(name)); /* no '+ 1', it's already accounted for */
        pn->next = cache;
        pn->nip = nip;
        pn->is_host = is_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));
        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)
{
        if (sin6->sin6_family != AF_INET6) {
                dbg("rresolve: unsupported address family %d!",
                                sin6->sin6_family);
                errno = EAFNOSUPPORT;
                return NULL;
        }
        if (numeric & 0x7FFF) {
                return xmalloc_sockaddr2dotted_noport((void*)sin6);
        }
        if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
                if (numeric & 0x8000)
                        return xstrdup("default");
                return xstrdup("*");
        }

        return xmalloc_sockaddr2host_noport((void*)sin6);
}

#endif  /* CONFIG_FEATURE_IPV6 */