source: MondoRescue/branches/2.2.5/mindi-busybox/libbb/xconnect.c

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Connect to host at port using address resolution from getaddrinfo
 *
 */

#include <netinet/in.h>
#include "libbb.h"

void setsockopt_reuseaddr(int fd)
{
    setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &const_int_1, sizeof(const_int_1));
}
int setsockopt_broadcast(int fd)
{
    return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &const_int_1, sizeof(const_int_1));
}

void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen)
{
    if (connect(s, s_addr, addrlen) < 0) {
        if (ENABLE_FEATURE_CLEAN_UP)
            close(s);
        if (s_addr->sa_family == AF_INET)
            bb_perror_msg_and_die("%s (%s)",
                "cannot connect to remote host",
                inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr));
        bb_perror_msg_and_die("cannot connect to remote host");
    }
}

/* Return port number for a service.
 * If "port" is a number use it as the port.
 * If "port" is a name it is looked up in /etc/services, if it isnt found return
 * default_port */
unsigned bb_lookup_port(const char *port, const char *protocol, unsigned default_port)
{
    unsigned port_nr = default_port;
    if (port) {
        int old_errno;

        /* Since this is a lib function, we're not allowed to reset errno to 0.
         * Doing so could break an app that is deferring checking of errno. */
        old_errno = errno;
        port_nr = bb_strtou(port, NULL, 10);
        if (errno || port_nr > 65535) {
            struct servent *tserv = getservbyname(port, protocol);
            port_nr = default_port;
            if (tserv)
                port_nr = ntohs(tserv->s_port);
        }
        errno = old_errno;
    }
    return (uint16_t)port_nr;
}


/* "Old" networking API - only IPv4 */

/*
void bb_lookup_host(struct sockaddr_in *s_in, const char *host)
{
    struct hostent *he;

    memset(s_in, 0, sizeof(struct sockaddr_in));
    s_in->sin_family = AF_INET;
    he = xgethostbyname(host);
    memcpy(&(s_in->sin_addr), he->h_addr_list[0], he->h_length);
}


int xconnect_tcp_v4(struct sockaddr_in *s_addr)
{
    int s = xsocket(AF_INET, SOCK_STREAM, 0);
    xconnect(s, (struct sockaddr*) s_addr, sizeof(*s_addr));
    return s;
}
*/

/* "New" networking API */


int get_nport(const struct sockaddr *sa)
{
#if ENABLE_FEATURE_IPV6
    if (sa->sa_family == AF_INET6) {
        return ((struct sockaddr_in6*)sa)->sin6_port;
    }
#endif
    if (sa->sa_family == AF_INET) {
        return ((struct sockaddr_in*)sa)->sin_port;
    }
    /* What? UNIX socket? IPX?? :) */
    return -1;
}

void set_nport(len_and_sockaddr *lsa, unsigned port)
{
#if ENABLE_FEATURE_IPV6
    if (lsa->sa.sa_family == AF_INET6) {
        lsa->sin6.sin6_port = port;
        return;
    }
#endif
    if (lsa->sa.sa_family == AF_INET) {
        lsa->sin.sin_port = port;
        return;
    }
    /* What? UNIX socket? IPX?? :) */
}

/* We hijack this constant to mean something else */
/* It doesn't hurt because we will remove this bit anyway */
#define DIE_ON_ERROR AI_CANONNAME

/* host: "1.2.3.4[:port]", "www.google.com[:port]"
 * port: if neither of above specifies port # */
static len_and_sockaddr* str2sockaddr(
        const char *host, int port,
USE_FEATURE_IPV6(sa_family_t af,)
        int ai_flags)
{
    int rc;
    len_and_sockaddr *r = NULL;
    struct addrinfo *result = NULL;
    const char *org_host = host; /* only for error msg */
    const char *cp;
    struct addrinfo hint;

    /* Ugly parsing of host:addr */
    if (ENABLE_FEATURE_IPV6 && host[0] == '[') {
        host++;
        cp = strchr(host, ']');
        if (!cp || cp[1] != ':') /* Malformed: must have [xx]:nn */
            bb_error_msg_and_die("bad address '%s'", org_host);
            //return r; /* return NULL */
    } else {
        cp = strrchr(host, ':');
        if (ENABLE_FEATURE_IPV6 && cp && strchr(host, ':') != cp) {
            /* There is more than one ':' (e.g. "::1") */
            cp = NULL; /* it's not a port spec */
        }
    }
    if (cp) {
        int sz = cp - host + 1;
        host = safe_strncpy(alloca(sz), host, sz);
        if (ENABLE_FEATURE_IPV6 && *cp != ':')
            cp++; /* skip ']' */
        cp++; /* skip ':' */
        port = xatou16(cp);
    }

    memset(&hint, 0 , sizeof(hint));
#if !ENABLE_FEATURE_IPV6
    hint.ai_family = AF_INET; /* do not try to find IPv6 */
#else
    hint.ai_family = af;
#endif
    /* Needed. Or else we will get each address thrice (or more)
     * for each possible socket type (tcp,udp,raw...): */
    hint.ai_socktype = SOCK_STREAM;
    hint.ai_flags = ai_flags & ~DIE_ON_ERROR;
    rc = getaddrinfo(host, NULL, &hint, &result);
    if (rc || !result) {
        bb_error_msg("bad address '%s'", org_host);
        if (ai_flags & DIE_ON_ERROR)
            xfunc_die();
        goto ret;
    }
    r = xmalloc(offsetof(len_and_sockaddr, sa) + result->ai_addrlen);
    r->len = result->ai_addrlen;
    memcpy(&r->sa, result->ai_addr, result->ai_addrlen);
    set_nport(r, htons(port));
 ret:
    freeaddrinfo(result);
    return r;
}
#if !ENABLE_FEATURE_IPV6
#define str2sockaddr(host, port, af, ai_flags) str2sockaddr(host, port, ai_flags)
#endif

#if ENABLE_FEATURE_IPV6
len_and_sockaddr* host_and_af2sockaddr(const char *host, int port, sa_family_t af)
{
    return str2sockaddr(host, port, af, 0);
}

len_and_sockaddr* xhost_and_af2sockaddr(const char *host, int port, sa_family_t af)
{
    return str2sockaddr(host, port, af, DIE_ON_ERROR);
}
#endif

len_and_sockaddr* host2sockaddr(const char *host, int port)
{
    return str2sockaddr(host, port, AF_UNSPEC, 0);
}

len_and_sockaddr* xhost2sockaddr(const char *host, int port)
{
    return str2sockaddr(host, port, AF_UNSPEC, DIE_ON_ERROR);
}

len_and_sockaddr* xdotted2sockaddr(const char *host, int port)
{
    return str2sockaddr(host, port, AF_UNSPEC, AI_NUMERICHOST | DIE_ON_ERROR);
}

int xsocket_type(len_and_sockaddr **lsap, USE_FEATURE_IPV6(int family,) int sock_type)
{
    SKIP_FEATURE_IPV6(enum { family = AF_INET };)
    len_and_sockaddr *lsa;
    int fd;
    int len;

#if ENABLE_FEATURE_IPV6
    if (family == AF_UNSPEC) {
        fd = socket(AF_INET6, sock_type, 0);
        if (fd >= 0) {
            family = AF_INET6;
            goto done;
        }
        family = AF_INET;
    }
#endif
    fd = xsocket(family, sock_type, 0);
    len = sizeof(struct sockaddr_in);
#if ENABLE_FEATURE_IPV6
    if (family == AF_INET6) {
 done:
        len = sizeof(struct sockaddr_in6);
    }
#endif
    lsa = xzalloc(offsetof(len_and_sockaddr, sa) + len);
    lsa->len = len;
    lsa->sa.sa_family = family;
    *lsap = lsa;
    return fd;
}

int xsocket_stream(len_and_sockaddr **lsap)
{
    return xsocket_type(lsap, USE_FEATURE_IPV6(AF_UNSPEC,) SOCK_STREAM);
}

static int create_and_bind_or_die(const char *bindaddr, int port, int sock_type)
{
    int fd;
    len_and_sockaddr *lsa;

    if (bindaddr && bindaddr[0]) {
        lsa = xdotted2sockaddr(bindaddr, port);
        /* user specified bind addr dictates family */
        fd = xsocket(lsa->sa.sa_family, sock_type, 0);
    } else {
        fd = xsocket_type(&lsa, USE_FEATURE_IPV6(AF_UNSPEC,) sock_type);
        set_nport(lsa, htons(port));
    }
    setsockopt_reuseaddr(fd);
    xbind(fd, &lsa->sa, lsa->len);
    free(lsa);
    return fd;
}

int create_and_bind_stream_or_die(const char *bindaddr, int port)
{
    return create_and_bind_or_die(bindaddr, port, SOCK_STREAM);
}

int create_and_bind_dgram_or_die(const char *bindaddr, int port)
{
    return create_and_bind_or_die(bindaddr, port, SOCK_DGRAM);
}


int create_and_connect_stream_or_die(const char *peer, int port)
{
    int fd;
    len_and_sockaddr *lsa;

    lsa = xhost2sockaddr(peer, port);
    fd = xsocket(lsa->sa.sa_family, SOCK_STREAM, 0);
    setsockopt_reuseaddr(fd);
    xconnect(fd, &lsa->sa, lsa->len);
    free(lsa);
    return fd;
}

int xconnect_stream(const len_and_sockaddr *lsa)
{
    int fd = xsocket(lsa->sa.sa_family, SOCK_STREAM, 0);
    xconnect(fd, &lsa->sa, lsa->len);
    return fd;
}

/* We hijack this constant to mean something else */
/* It doesn't hurt because we will add this bit anyway */
#define IGNORE_PORT NI_NUMERICSERV
static char* sockaddr2str(const struct sockaddr *sa, int flags)
{
    char host[128];
    char serv[16];
    int rc;
    socklen_t salen;

    salen = LSA_SIZEOF_SA;
#if ENABLE_FEATURE_IPV6
    if (sa->sa_family == AF_INET)
        salen = sizeof(struct sockaddr_in);
    if (sa->sa_family == AF_INET6)
        salen = sizeof(struct sockaddr_in6);
#endif
    rc = getnameinfo(sa, salen,
            host, sizeof(host),
    /* can do ((flags & IGNORE_PORT) ? NULL : serv) but why bother? */
            serv, sizeof(serv),
            /* do not resolve port# into service _name_ */
            flags | NI_NUMERICSERV
    );
    if (rc)
        return NULL;
    if (flags & IGNORE_PORT)
        return xstrdup(host);
#if ENABLE_FEATURE_IPV6
    if (sa->sa_family == AF_INET6) {
        if (strchr(host, ':')) /* heh, it's not a resolved hostname */
            return xasprintf("[%s]:%s", host, serv);
        /*return xasprintf("%s:%s", host, serv);*/
        /* - fall through instead */
    }
#endif
    /* For now we don't support anything else, so it has to be INET */
    /*if (sa->sa_family == AF_INET)*/
        return xasprintf("%s:%s", host, serv);
    /*return xstrdup(host);*/
}

char* xmalloc_sockaddr2host(const struct sockaddr *sa)
{
    return sockaddr2str(sa, 0);
}

char* xmalloc_sockaddr2host_noport(const struct sockaddr *sa)
{
    return sockaddr2str(sa, IGNORE_PORT);
}

char* xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa)
{
    return sockaddr2str(sa, NI_NAMEREQD | IGNORE_PORT);
}
char* xmalloc_sockaddr2dotted(const struct sockaddr *sa)
{
    return sockaddr2str(sa, NI_NUMERICHOST);
}

char* xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa)
{
    return sockaddr2str(sa, NI_NUMERICHOST | IGNORE_PORT);
}