LXR busybox/libbb/xconnect.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Utility routines.
   4 *
   5 * Connect to host at port using address resolution from getaddrinfo
   6 *
   7 * Licensed under GPLv2, see file LICENSE in this tarball for details.
   8 */
   9
  10#include <netinet/in.h>
  11#include <net/if.h>
  12#include <sys/un.h>
  13#include "libbb.h"
  14
  15void FAST_FUNC setsockopt_reuseaddr(int fd)
  16{
  17        setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &const_int_1, sizeof(const_int_1));
  18}
  19int FAST_FUNC setsockopt_broadcast(int fd)
  20{
  21        return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &const_int_1, sizeof(const_int_1));
  22}
  23int FAST_FUNC setsockopt_bindtodevice(int fd, const char *iface)
  24{
  25        int r;
  26        struct ifreq ifr;
  27        strncpy_IFNAMSIZ(ifr.ifr_name, iface);
  28        /* NB: passing (iface, strlen(iface) + 1) does not work!
  29         * (maybe it works on _some_ kernels, but not on 2.6.26)
  30         * Actually, ifr_name is at offset 0, and in practice
  31         * just giving char[IFNAMSIZ] instead of struct ifreq works too.
  32         * But just in case it's not true on some obscure arch... */
  33        r = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));
  34        if (r)
  35                bb_perror_msg("can't bind to interface %s", iface);
  36        return r;
  37}
  38
  39len_and_sockaddr* FAST_FUNC get_sock_lsa(int fd)
  40{
  41        len_and_sockaddr lsa;
  42        len_and_sockaddr *lsa_ptr;
  43
  44        lsa.len = LSA_SIZEOF_SA;
  45        if (getsockname(fd, &lsa.u.sa, &lsa.len) != 0)
  46                return NULL;
  47
  48        lsa_ptr = xzalloc(LSA_LEN_SIZE + lsa.len);
  49        if (lsa.len > LSA_SIZEOF_SA) { /* rarely (if ever) happens */
  50                lsa_ptr->len = lsa.len;
  51                getsockname(fd, &lsa_ptr->u.sa, &lsa_ptr->len);
  52        } else {
  53                memcpy(lsa_ptr, &lsa, LSA_LEN_SIZE + lsa.len);
  54        }
  55        return lsa_ptr;
  56}
  57
  58void FAST_FUNC xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen)
  59{
  60        if (connect(s, s_addr, addrlen) < 0) {
  61                if (ENABLE_FEATURE_CLEAN_UP)
  62                        close(s);
  63                if (s_addr->sa_family == AF_INET)
  64                        bb_perror_msg_and_die("%s (%s)",
  65                                "cannot connect to remote host",
  66                                inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr));
  67                bb_perror_msg_and_die("cannot connect to remote host");
  68        }
  69}
  70
  71/* Return port number for a service.
  72 * If "port" is a number use it as the port.
  73 * If "port" is a name it is looked up in /etc/services,
  74 * if it isnt found return default_port
  75 */
  76unsigned FAST_FUNC bb_lookup_port(const char *port, const char *protocol, unsigned default_port)
  77{
  78        unsigned port_nr = default_port;
  79        if (port) {
  80                int old_errno;
  81
  82                /* Since this is a lib function, we're not allowed to reset errno to 0.
  83                 * Doing so could break an app that is deferring checking of errno. */
  84                old_errno = errno;
  85                port_nr = bb_strtou(port, NULL, 10);
  86                if (errno || port_nr > 65535) {
  87                        struct servent *tserv = getservbyname(port, protocol);
  88                        port_nr = default_port;
  89                        if (tserv)
  90                                port_nr = ntohs(tserv->s_port);
  91                }
  92                errno = old_errno;
  93        }
  94        return (uint16_t)port_nr;
  95}
  96
  97
  98/* "Old" networking API - only IPv4 */
  99
 100/*
 101void FAST_FUNC bb_lookup_host(struct sockaddr_in *s_in, const char *host)
 102{
 103        struct hostent *he;
 104
 105        memset(s_in, 0, sizeof(struct sockaddr_in));
 106        s_in->sin_family = AF_INET;
 107        he = xgethostbyname(host);
 108        memcpy(&(s_in->sin_addr), he->h_addr_list[0], he->h_length);
 109}
 110
 111
 112int FAST_FUNC xconnect_tcp_v4(struct sockaddr_in *s_addr)
 113{
 114        int s = xsocket(AF_INET, SOCK_STREAM, 0);
 115        xconnect(s, (struct sockaddr*) s_addr, sizeof(*s_addr));
 116        return s;
 117}
 118*/
 119
 120/* "New" networking API */
 121
 122
 123int FAST_FUNC get_nport(const struct sockaddr *sa)
 124{
 125#if ENABLE_FEATURE_IPV6
 126        if (sa->sa_family == AF_INET6) {
 127                return ((struct sockaddr_in6*)sa)->sin6_port;
 128        }
 129#endif
 130        if (sa->sa_family == AF_INET) {
 131                return ((struct sockaddr_in*)sa)->sin_port;
 132        }
 133        /* What? UNIX socket? IPX?? :) */
 134        return -1;
 135}
 136
 137void FAST_FUNC set_nport(len_and_sockaddr *lsa, unsigned port)
 138{
 139#if ENABLE_FEATURE_IPV6
 140        if (lsa->u.sa.sa_family == AF_INET6) {
 141                lsa->u.sin6.sin6_port = port;
 142                return;
 143        }
 144#endif
 145        if (lsa->u.sa.sa_family == AF_INET) {
 146                lsa->u.sin.sin_port = port;
 147                return;
 148        }
 149        /* What? UNIX socket? IPX?? :) */
 150}
 151
 152/* We hijack this constant to mean something else */
 153/* It doesn't hurt because we will remove this bit anyway */
 154#define DIE_ON_ERROR AI_CANONNAME
 155
 156/* host: "1.2.3.4[:port]", "www.google.com[:port]"
 157 * port: if neither of above specifies port # */
 158static len_and_sockaddr* str2sockaddr(
 159                const char *host, int port,
 160IF_FEATURE_IPV6(sa_family_t af,)
 161                int ai_flags)
 162{
 163        int rc;
 164        len_and_sockaddr *r;
 165        struct addrinfo *result = NULL;
 166        struct addrinfo *used_res;
 167        const char *org_host = host; /* only for error msg */
 168        const char *cp;
 169        struct addrinfo hint;
 170
 171        if (ENABLE_FEATURE_UNIX_LOCAL && strncmp(host, "local:", 6) == 0) {
 172                struct sockaddr_un *sun;
 173
 174                r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_un));
 175                r->len = sizeof(struct sockaddr_un);
 176                r->u.sa.sa_family = AF_UNIX;
 177                sun = (struct sockaddr_un *)&r->u.sa;
 178                safe_strncpy(sun->sun_path, host + 6, sizeof(sun->sun_path));
 179                return r;
 180        }
 181
 182        r = NULL;
 183
 184        /* Ugly parsing of host:addr */
 185        if (ENABLE_FEATURE_IPV6 && host[0] == '[') {
 186                /* Even uglier parsing of [xx]:nn */
 187                host++;
 188                cp = strchr(host, ']');
 189                if (!cp || (cp[1] != ':' && cp[1] != '\0')) {
 190                        /* Malformed: must be [xx]:nn or [xx] */
 191                        bb_error_msg("bad address '%s'", org_host);
 192                        if (ai_flags & DIE_ON_ERROR)
 193                                xfunc_die();
 194                        return NULL;
 195                }
 196        } else {
 197                cp = strrchr(host, ':');
 198                if (ENABLE_FEATURE_IPV6 && cp && strchr(host, ':') != cp) {
 199                        /* There is more than one ':' (e.g. "::1") */
 200                        cp = NULL; /* it's not a port spec */
 201                }
 202        }
 203        if (cp) { /* points to ":" or "]:" */
 204                int sz = cp - host + 1;
 205
 206                host = safe_strncpy(alloca(sz), host, sz);
 207                if (ENABLE_FEATURE_IPV6 && *cp != ':') {
 208                        cp++; /* skip ']' */
 209                        if (*cp == '\0') /* [xx] without port */
 210                                goto skip;
 211                }
 212                cp++; /* skip ':' */
 213                port = bb_strtou(cp, NULL, 10);
 214                if (errno || (unsigned)port > 0xffff) {
 215                        bb_error_msg("bad port spec '%s'", org_host);
 216                        if (ai_flags & DIE_ON_ERROR)
 217                                xfunc_die();
 218                        return NULL;
 219                }
 220 skip: ;
 221        }
 222
 223        memset(&hint, 0 , sizeof(hint));
 224#if !ENABLE_FEATURE_IPV6
 225        hint.ai_family = AF_INET; /* do not try to find IPv6 */
 226#else
 227        hint.ai_family = af;
 228#endif
 229        /* Needed. Or else we will get each address thrice (or more)
 230         * for each possible socket type (tcp,udp,raw...): */
 231        hint.ai_socktype = SOCK_STREAM;
 232        hint.ai_flags = ai_flags & ~DIE_ON_ERROR;
 233        rc = getaddrinfo(host, NULL, &hint, &result);
 234        if (rc || !result) {
 235                bb_error_msg("bad address '%s'", org_host);
 236                if (ai_flags & DIE_ON_ERROR)
 237                        xfunc_die();
 238                goto ret;
 239        }
 240        used_res = result;
 241#if ENABLE_FEATURE_PREFER_IPV4_ADDRESS
 242        while (1) {
 243                if (used_res->ai_family == AF_INET)
 244                        break;
 245                used_res = used_res->ai_next;
 246                if (!used_res) {
 247                        used_res = result;
 248                        break;
 249                }
 250        }
 251#endif
 252        r = xmalloc(offsetof(len_and_sockaddr, u.sa) + used_res->ai_addrlen);
 253        r->len = used_res->ai_addrlen;
 254        memcpy(&r->u.sa, used_res->ai_addr, used_res->ai_addrlen);
 255        set_nport(r, htons(port));
 256 ret:
 257        freeaddrinfo(result);
 258        return r;
 259}
 260#if !ENABLE_FEATURE_IPV6
 261#define str2sockaddr(host, port, af, ai_flags) str2sockaddr(host, port, ai_flags)
 262#endif
 263
 264#if ENABLE_FEATURE_IPV6
 265len_and_sockaddr* FAST_FUNC host_and_af2sockaddr(const char *host, int port, sa_family_t af)
 266{
 267        return str2sockaddr(host, port, af, 0);
 268}
 269
 270len_and_sockaddr* FAST_FUNC xhost_and_af2sockaddr(const char *host, int port, sa_family_t af)
 271{
 272        return str2sockaddr(host, port, af, DIE_ON_ERROR);
 273}
 274#endif
 275
 276len_and_sockaddr* FAST_FUNC host2sockaddr(const char *host, int port)
 277{
 278        return str2sockaddr(host, port, AF_UNSPEC, 0);
 279}
 280
 281len_and_sockaddr* FAST_FUNC xhost2sockaddr(const char *host, int port)
 282{
 283        return str2sockaddr(host, port, AF_UNSPEC, DIE_ON_ERROR);
 284}
 285
 286len_and_sockaddr* FAST_FUNC xdotted2sockaddr(const char *host, int port)
 287{
 288        return str2sockaddr(host, port, AF_UNSPEC, AI_NUMERICHOST | DIE_ON_ERROR);
 289}
 290
 291#undef xsocket_type
 292int FAST_FUNC xsocket_type(len_and_sockaddr **lsap, IF_FEATURE_IPV6(int family,) int sock_type)
 293{
 294        IF_NOT_FEATURE_IPV6(enum { family = AF_INET };)
 295        len_and_sockaddr *lsa;
 296        int fd;
 297        int len;
 298
 299#if ENABLE_FEATURE_IPV6
 300        if (family == AF_UNSPEC) {
 301                fd = socket(AF_INET6, sock_type, 0);
 302                if (fd >= 0) {
 303                        family = AF_INET6;
 304                        goto done;
 305                }
 306                family = AF_INET;
 307        }
 308#endif
 309        fd = xsocket(family, sock_type, 0);
 310        len = sizeof(struct sockaddr_in);
 311#if ENABLE_FEATURE_IPV6
 312        if (family == AF_INET6) {
 313 done:
 314                len = sizeof(struct sockaddr_in6);
 315        }
 316#endif
 317        lsa = xzalloc(offsetof(len_and_sockaddr, u.sa) + len);
 318        lsa->len = len;
 319        lsa->u.sa.sa_family = family;
 320        *lsap = lsa;
 321        return fd;
 322}
 323
 324int FAST_FUNC xsocket_stream(len_and_sockaddr **lsap)
 325{
 326        return xsocket_type(lsap, IF_FEATURE_IPV6(AF_UNSPEC,) SOCK_STREAM);
 327}
 328
 329static int create_and_bind_or_die(const char *bindaddr, int port, int sock_type)
 330{
 331        int fd;
 332        len_and_sockaddr *lsa;
 333
 334        if (bindaddr && bindaddr[0]) {
 335                lsa = xdotted2sockaddr(bindaddr, port);
 336                /* user specified bind addr dictates family */
 337                fd = xsocket(lsa->u.sa.sa_family, sock_type, 0);
 338        } else {
 339                fd = xsocket_type(&lsa, IF_FEATURE_IPV6(AF_UNSPEC,) sock_type);
 340                set_nport(lsa, htons(port));
 341        }
 342        setsockopt_reuseaddr(fd);
 343        xbind(fd, &lsa->u.sa, lsa->len);
 344        free(lsa);
 345        return fd;
 346}
 347
 348int FAST_FUNC create_and_bind_stream_or_die(const char *bindaddr, int port)
 349{
 350        return create_and_bind_or_die(bindaddr, port, SOCK_STREAM);
 351}
 352
 353int FAST_FUNC create_and_bind_dgram_or_die(const char *bindaddr, int port)
 354{
 355        return create_and_bind_or_die(bindaddr, port, SOCK_DGRAM);
 356}
 357
 358
 359int FAST_FUNC create_and_connect_stream_or_die(const char *peer, int port)
 360{
 361        int fd;
 362        len_and_sockaddr *lsa;
 363
 364        lsa = xhost2sockaddr(peer, port);
 365        fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
 366        setsockopt_reuseaddr(fd);
 367        xconnect(fd, &lsa->u.sa, lsa->len);
 368        free(lsa);
 369        return fd;
 370}
 371
 372int FAST_FUNC xconnect_stream(const len_and_sockaddr *lsa)
 373{
 374        int fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
 375        xconnect(fd, &lsa->u.sa, lsa->len);
 376        return fd;
 377}
 378
 379/* We hijack this constant to mean something else */
 380/* It doesn't hurt because we will add this bit anyway */
 381#define IGNORE_PORT NI_NUMERICSERV
 382static char* FAST_FUNC sockaddr2str(const struct sockaddr *sa, int flags)
 383{
 384        char host[128];
 385        char serv[16];
 386        int rc;
 387        socklen_t salen;
 388
 389        if (ENABLE_FEATURE_UNIX_LOCAL && sa->sa_family == AF_UNIX) {
 390                struct sockaddr_un *sun = (struct sockaddr_un *)sa;
 391                return xasprintf("local:%.*s",
 392                                (int) sizeof(sun->sun_path),
 393                                sun->sun_path);
 394        }
 395
 396        salen = LSA_SIZEOF_SA;
 397#if ENABLE_FEATURE_IPV6
 398        if (sa->sa_family == AF_INET)
 399                salen = sizeof(struct sockaddr_in);
 400        if (sa->sa_family == AF_INET6)
 401                salen = sizeof(struct sockaddr_in6);
 402#endif
 403        rc = getnameinfo(sa, salen,
 404                        host, sizeof(host),
 405        /* can do ((flags & IGNORE_PORT) ? NULL : serv) but why bother? */
 406                        serv, sizeof(serv),
 407                        /* do not resolve port# into service _name_ */
 408                        flags | NI_NUMERICSERV
 409        );
 410        if (rc)
 411                return NULL;
 412        if (flags & IGNORE_PORT)
 413                return xstrdup(host);
 414#if ENABLE_FEATURE_IPV6
 415        if (sa->sa_family == AF_INET6) {
 416                if (strchr(host, ':')) /* heh, it's not a resolved hostname */
 417                        return xasprintf("[%s]:%s", host, serv);
 418                /*return xasprintf("%s:%s", host, serv);*/
 419                /* - fall through instead */
 420        }
 421#endif
 422        /* For now we don't support anything else, so it has to be INET */
 423        /*if (sa->sa_family == AF_INET)*/
 424                return xasprintf("%s:%s", host, serv);
 425        /*return xstrdup(host);*/
 426}
 427
 428char* FAST_FUNC xmalloc_sockaddr2host(const struct sockaddr *sa)
 429{
 430        return sockaddr2str(sa, 0);
 431}
 432
 433char* FAST_FUNC xmalloc_sockaddr2host_noport(const struct sockaddr *sa)
 434{
 435        return sockaddr2str(sa, IGNORE_PORT);
 436}
 437
 438char* FAST_FUNC xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa)
 439{
 440        return sockaddr2str(sa, NI_NAMEREQD | IGNORE_PORT);
 441}
 442char* FAST_FUNC xmalloc_sockaddr2dotted(const struct sockaddr *sa)
 443{
 444        return sockaddr2str(sa, NI_NUMERICHOST);
 445}
 446
 447char* FAST_FUNC xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa)
 448{
 449        return sockaddr2str(sa, NI_NUMERICHOST | IGNORE_PORT);
 450}
 451