queryperf/missing/getaddrinfo.c

/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <netdb.h>
#include <resolv.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <ctype.h>
#include <unistd.h>

#include "addrinfo.h"

#define SUCCESS 0
#define ANY 0
#define YES 1
#define NO  0

static const char in_addrany[] = { 0, 0, 0, 0 };
static const char in6_addrany[] = {
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
static const char in_loopback[] = { 127, 0, 0, 1 };
static const char in6_loopback[] = {
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
};

struct sockinet {
    u_char  si_len;
    u_char  si_family;
    u_short si_port;
};

static struct afd {
    int a_af;
    int a_addrlen;
    int a_socklen;
    int a_off;
    const char *a_addrany;
    const char *a_loopback;
} afdl [] = {
#ifdef INET6
#define N_INET6 0
    {PF_INET6, sizeof(struct in6_addr),
     sizeof(struct sockaddr_in6),
     offsetof(struct sockaddr_in6, sin6_addr),
     in6_addrany, in6_loopback},
#define N_INET  1
#else
#define N_INET  0
#endif
    {PF_INET, sizeof(struct in_addr),
     sizeof(struct sockaddr_in),
     offsetof(struct sockaddr_in, sin_addr),
     in_addrany, in_loopback},
    {0, 0, 0, 0, NULL, NULL},
};

#ifdef INET6
#define PTON_MAX    16
#else
#define PTON_MAX    4
#endif


static int get_name(const char *, struct afd *,
            struct addrinfo **, char *, struct addrinfo *,
            int);
static int get_addr(const char *, int, struct addrinfo **,
            struct addrinfo *, int);
static int get_addr0(const char *, int, struct addrinfo **,
             struct addrinfo *, int);
static int str_isnumber(const char *);

static char *ai_errlist[] = {
    "Success",
    "Address family for hostname not supported",    /* EAI_ADDRFAMILY */
    "Temporary failure in name resolution",     /* EAI_AGAIN      */
    "Invalid value for ai_flags",               /* EAI_BADFLAGS   */
    "Non-recoverable failure in name resolution",   /* EAI_FAIL       */
    "ai_family not supported",          /* EAI_FAMILY     */
    "Memory allocation failure",            /* EAI_MEMORY     */
    "No address associated with hostname",      /* EAI_NODATA     */
    "hostname nor servname provided, or not known",/* EAI_NONAME     */
    "servname not supported for ai_socktype",   /* EAI_SERVICE    */
    "ai_socktype not supported",            /* EAI_SOCKTYPE   */
    "System error returned in errno",       /* EAI_SYSTEM     */
    "Invalid value for hints",          /* EAI_BADHINTS   */
    "Resolved protocol is unknown",         /* EAI_PROTOCOL   */
    "Unknown error",                /* EAI_MAX        */
};

#define GET_CANONNAME(ai, str) \
if (pai->ai_flags & AI_CANONNAME) {\
    if (((ai)->ai_canonname = (char *)malloc(strlen(str) + 1)) != NULL) {\
        strcpy((ai)->ai_canonname, (str));\
    } else {\
        error = EAI_MEMORY;\
        goto free;\
    }\
}

#ifdef HAVE_SA_LEN
#define SET_AILEN(ai,l) (ai)->ai_addr->sa_len = (ai)->ai_addrlen = (l)
#else
#define SET_AILEN(ai,l) (ai)->ai_addrlen = (l)
#endif

#define GET_AI(ai, afd, addr, port) {\
    char *p;\
    if (((ai) = (struct addrinfo *)malloc(sizeof(struct addrinfo) +\
                          ((afd)->a_socklen)))\
        == NULL) {\
        error = EAI_MEMORY;\
        goto free;\
    }\
    memcpy(ai, pai, sizeof(struct addrinfo));\
    (ai)->ai_addr = (struct sockaddr *)((ai) + 1);\
    memset((ai)->ai_addr, 0, (afd)->a_socklen);\
    SET_AILEN((ai), (afd)->a_socklen);\
    (ai)->ai_addr->sa_family = (ai)->ai_family = (afd)->a_af;\
    ((struct sockinet *)(ai)->ai_addr)->si_port = port;\
    p = (char *)((ai)->ai_addr);\
    memcpy(p + (afd)->a_off, (addr), (afd)->a_addrlen);\
}

#define ERR(err) { error = (err); goto bad; }

char *
gai_strerror(ecode)
    int ecode;
{
    if (ecode < 0 || ecode > EAI_MAX)
        ecode = EAI_MAX;
    return ai_errlist[ecode];
}

void
freeaddrinfo(ai)
    struct addrinfo *ai;
{
    struct addrinfo *next;

    do {
        next = ai->ai_next;
        if (ai->ai_canonname)
            free(ai->ai_canonname);
        /* no need to free(ai->ai_addr) */
        free(ai);
    } while ((ai = next) != NULL);
}

static int
str_isnumber(p)
    const char *p;
{
    char *q = (char *)p;
    while (*q) {
        if (! isdigit(*q))
            return NO;
        q++;
    }
    return YES;
}

int
getaddrinfo(hostname, servname, hints, res)
    const char *hostname, *servname;
    const struct addrinfo *hints;
    struct addrinfo **res;
{
    struct addrinfo sentinel;
    struct addrinfo *top = NULL;
    struct addrinfo *cur;
    int i, error = 0;
    char pton[PTON_MAX];
    struct addrinfo ai;
    struct addrinfo *pai;
    u_short port;

    /* initialize file static vars */
    sentinel.ai_next = NULL;
    cur = &sentinel;
    pai = &ai;
    pai->ai_flags = 0;
    pai->ai_family = PF_UNSPEC;
    pai->ai_socktype = ANY;
    pai->ai_protocol = ANY;
    pai->ai_addrlen = 0;
    pai->ai_canonname = NULL;
    pai->ai_addr = NULL;
    pai->ai_next = NULL;
    port = ANY;

    if (hostname == NULL && servname == NULL)
        return EAI_NONAME;
    if (hints) {
        /* error check for hints */
        if (hints->ai_addrlen || hints->ai_canonname ||
            hints->ai_addr || hints->ai_next)
            ERR(EAI_BADHINTS); /* xxx */
        if (hints->ai_flags & ~AI_MASK)
            ERR(EAI_BADFLAGS);
        switch (hints->ai_family) {
        case PF_UNSPEC:
        case PF_INET:
#ifdef INET6
        case PF_INET6:
#endif
            break;
        default:
            ERR(EAI_FAMILY);
        }
        memcpy(pai, hints, sizeof(*pai));
        switch (pai->ai_socktype) {
        case ANY:
            switch (pai->ai_protocol) {
            case ANY:
                break;
            case IPPROTO_UDP:
                pai->ai_socktype = SOCK_DGRAM;
                break;
            case IPPROTO_TCP:
                pai->ai_socktype = SOCK_STREAM;
                break;
            default:
                pai->ai_socktype = SOCK_RAW;
                break;
            }
            break;
        case SOCK_RAW:
            break;
        case SOCK_DGRAM:
            if (pai->ai_protocol != IPPROTO_UDP &&
                pai->ai_protocol != ANY)
                ERR(EAI_BADHINTS);  /*xxx*/
            pai->ai_protocol = IPPROTO_UDP;
            break;
        case SOCK_STREAM:
            if (pai->ai_protocol != IPPROTO_TCP &&
                pai->ai_protocol != ANY)
                ERR(EAI_BADHINTS);  /*xxx*/
            pai->ai_protocol = IPPROTO_TCP;
            break;
        default:
            ERR(EAI_SOCKTYPE);
            break;
        }
    }

    /*
     * service port
     */
    if (servname) {
        if (str_isnumber(servname)) {
            if (pai->ai_socktype == ANY) {
                /* caller accept *ANY* socktype */
                pai->ai_socktype = SOCK_DGRAM;
                pai->ai_protocol = IPPROTO_UDP;
            }
            port = htons(atoi(servname));
        } else {
            struct servent *sp;
            char *proto;

            proto = NULL;
            switch (pai->ai_socktype) {
            case ANY:
                proto = NULL;
                break;
            case SOCK_DGRAM:
                proto = "udp";
                break;
            case SOCK_STREAM:
                proto = "tcp";
                break;
            default:
                fprintf(stderr, "panic!\n");
                break;
            }
            if ((sp = getservbyname(servname, proto)) == NULL)
                ERR(EAI_SERVICE);
            port = sp->s_port;
            if (pai->ai_socktype == ANY) {
                if (strcmp(sp->s_proto, "udp") == 0) {
                    pai->ai_socktype = SOCK_DGRAM;
                    pai->ai_protocol = IPPROTO_UDP;
                } else if (strcmp(sp->s_proto, "tcp") == 0) {
                    pai->ai_socktype = SOCK_STREAM;
                    pai->ai_protocol = IPPROTO_TCP;
                } else
                    ERR(EAI_PROTOCOL);  /*xxx*/
            }
        }
    }

    /*
     * hostname == NULL.
     * passive socket -> anyaddr (0.0.0.0 or ::)
     * non-passive socket -> localhost (127.0.0.1 or ::1)
     */
    if (hostname == NULL) {
        struct afd *afd;
        int s;

        for (afd = &afdl[0]; afd->a_af; afd++) {
            if (!(pai->ai_family == PF_UNSPEC
               || pai->ai_family == afd->a_af)) {
                continue;
            }

            /*
             * filter out AFs that are not supported by the kernel
             * XXX errno?
             */
            s = socket(afd->a_af, SOCK_DGRAM, 0);
            if (s < 0)
                continue;
            close(s);

            if (pai->ai_flags & AI_PASSIVE) {
                GET_AI(cur->ai_next, afd, afd->a_addrany, port);
                /* xxx meaningless?
                 * GET_CANONNAME(cur->ai_next, "anyaddr");
                 */
            } else {
                GET_AI(cur->ai_next, afd, afd->a_loopback,
                    port);
                /* xxx meaningless?
                 * GET_CANONNAME(cur->ai_next, "localhost");
                 */
            }
            cur = cur->ai_next;
        }
        top = sentinel.ai_next;
        if (top)
            goto good;
        else
            ERR(EAI_FAMILY);
    }

    /* hostname as numeric name */
    for (i = 0; afdl[i].a_af; i++) {
        if (inet_pton(afdl[i].a_af, hostname, pton) == 1) {
            u_long v4a;
            u_char pfx;

            switch (afdl[i].a_af) {
            case AF_INET:
                v4a = ntohl(((struct in_addr *)pton)->s_addr);
                if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
                    pai->ai_flags &= ~AI_CANONNAME;
                v4a >>= IN_CLASSA_NSHIFT;
                if (v4a == 0 || v4a == IN_LOOPBACKNET)
                    pai->ai_flags &= ~AI_CANONNAME;
                break;
#ifdef INET6
            case AF_INET6:
                pfx = ((struct in6_addr *)pton)->s6_addr[0];
                if (pfx == 0 || pfx == 0xfe || pfx == 0xff)
                    pai->ai_flags &= ~AI_CANONNAME;
                break;
#endif
            }

            if (pai->ai_family == afdl[i].a_af ||
                pai->ai_family == PF_UNSPEC) {
                if (! (pai->ai_flags & AI_CANONNAME)) {
                    GET_AI(top, &afdl[i], pton, port);
                    goto good;
                }
                /*
                 * if AI_CANONNAME and if reverse lookup
                 * fail, return ai anyway to pacify
                 * calling application.
                 *
                 * XXX getaddrinfo() is a name->address
                 * translation function, and it looks strange
                 * that we do addr->name translation here.
                 */
                get_name(pton, &afdl[i], &top, pton, pai, port);
                goto good;
            } else
                ERR(EAI_FAMILY);    /*xxx*/
        }
    }

    if (pai->ai_flags & AI_NUMERICHOST)
        ERR(EAI_NONAME);

    /* hostname as alphabetical name */
    error = get_addr(hostname, pai->ai_family, &top, pai, port);
    if (error == 0) {
        if (top) {
 good:
            *res = top;
            return SUCCESS;
        } else
            error = EAI_FAIL;
    }
 free:
    if (top)
        freeaddrinfo(top);
 bad:
    *res = NULL;
    return error;
}

static int
get_name(addr, afd, res, numaddr, pai, port0)
    const char *addr;
    struct afd *afd;
    struct addrinfo **res;
    char *numaddr;
    struct addrinfo *pai;
    int port0;
{
    u_short port = port0 & 0xffff;
    struct hostent *hp;
    struct addrinfo *cur;
    int error = 0;
    hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
    if (hp && hp->h_name && hp->h_name[0] && hp->h_addr_list[0]) {
        GET_AI(cur, afd, hp->h_addr_list[0], port);
        GET_CANONNAME(cur, hp->h_name);
    } else
        GET_AI(cur, afd, numaddr, port);

    *res = cur;
    return SUCCESS;
 free:
    if (cur)
        freeaddrinfo(cur);

 /* bad: */
    *res = NULL;
    return error;
}

static int
get_addr(hostname, af, res0, pai, port0)
    const char *hostname;
    int af;
    struct addrinfo **res0;
    struct addrinfo *pai;
    int port0;
{
    int i, error, ekeep;
    struct addrinfo *cur;
    struct addrinfo **res;
    int retry;
    int s;

    res = res0;
    ekeep = 0;
    error = 0;
    for (i = 0; afdl[i].a_af; i++) {
        retry = 0;
        if (af == AF_UNSPEC) {
            /*
             * filter out AFs that are not supported by the kernel
             * XXX errno?
             */
            s = socket(afdl[i].a_af, SOCK_DGRAM, 0);
            if (s < 0)
                continue;
            close(s);
        } else {
            if (af != afdl[i].a_af)
                continue;
        }
        /* It is WRONG, we need getipnodebyname(). */
again:
        error = get_addr0(hostname, afdl[i].a_af, res, pai, port0);
        switch (error) {
        case EAI_AGAIN:
            if (++retry < 3)
                goto again;
            /* FALL THROUGH*/
        default:
            if (ekeep == 0)
                ekeep = error;
            break;
        }
        if (*res) {
            /* make chain of addrs */
            for (cur = *res;
                 cur && cur->ai_next;
                 cur = cur->ai_next)
                ;
            if (!cur)
                return EAI_FAIL;
            res = &cur->ai_next;
        }
    }

    /* if we got something, it's okay */
    if (*res0)
        return 0;

    return error ? error : ekeep;
}

static int
get_addr0(hostname, af, res, pai, port0)
    const char *hostname;
    int af;
    struct addrinfo **res;
    struct addrinfo *pai;
    int port0;
{
    u_short port = port0 & 0xffff;
    struct addrinfo sentinel;
    struct hostent *hp;
    struct addrinfo *top, *cur;
    struct afd *afd;
    int i, error = 0, h_error;
    char *ap;

    top = NULL;
    sentinel.ai_next = NULL;
    cur = &sentinel;

#ifdef HAVE_GETHOSTBYNAME2
    if (af == AF_UNSPEC) {
        error = EAI_FAIL;
        goto bad;
    }
    hp = gethostbyname2(hostname, af);
#else
    if (af != AF_UNSPEC && af != AF_INET) {
        error = EAI_FAIL;
        goto bad;
    }
    hp = gethostbyname(hostname);
#endif
    h_error = h_errno;

    if (hp == NULL) {
        switch (h_error) {
        case HOST_NOT_FOUND:
        case NO_DATA:
            error = EAI_NODATA;
            break;
        case TRY_AGAIN:
            error = EAI_AGAIN;
            break;
        case NO_RECOVERY:
        case NETDB_INTERNAL:
        default:
            error = EAI_FAIL;
            break;
        }
        goto bad;
    }

    if ((hp->h_name == NULL) || (hp->h_name[0] == 0) ||
        (hp->h_addr_list[0] == NULL))
        ERR(EAI_FAIL);

    for (i = 0; (ap = hp->h_addr_list[i]) != NULL; i++) {
        switch (af) {
#ifdef INET6
        case AF_INET6:
            afd = &afdl[N_INET6];
            break;
#endif
#ifndef INET6
        default:    /* AF_UNSPEC */
#endif
        case AF_INET:
            afd = &afdl[N_INET];
            break;
#ifdef INET6
        default:    /* AF_UNSPEC */
            if (IN6_IS_ADDR_V4MAPPED((struct in6_addr *)ap)) {
                ap += sizeof(struct in6_addr) -
                    sizeof(struct in_addr);
                afd = &afdl[N_INET];
            } else
                afd = &afdl[N_INET6];
            break;
#endif
        }
        GET_AI(cur->ai_next, afd, ap, port);
        if (cur == &sentinel) {
            top = cur->ai_next;
            GET_CANONNAME(top, hp->h_name);
        }
        cur = cur->ai_next;
    }
    *res = top;
    return SUCCESS;
 free:
    if (top)
        freeaddrinfo(top);
 bad:
    *res = NULL;
    return error;
}