/* vi: set sw=4 ts=4: */ /* * Utility routines. * * Connect to host at port using address resolution from getaddrinfo * * Licensed under GPLv2, see file LICENSE in this source tree. */ #include <sys/types.h> #include <sys/socket.h> /* netinet/in.h needs it */ #include <netinet/in.h> #include <net/if.h> #include <sys/un.h> #include "libbb.h" void FAST_FUNC setsockopt_reuseaddr(int fd) { setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &const_int_1, sizeof(const_int_1)); } int FAST_FUNC setsockopt_broadcast(int fd) { return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &const_int_1, sizeof(const_int_1)); } #ifdef SO_BINDTODEVICE int FAST_FUNC setsockopt_bindtodevice(int fd, const char *iface) { int r; struct ifreq ifr; strncpy_IFNAMSIZ(ifr.ifr_name, iface); /* NB: passing (iface, strlen(iface) + 1) does not work! * (maybe it works on _some_ kernels, but not on 2.6.26) * Actually, ifr_name is at offset 0, and in practice * just giving char[IFNAMSIZ] instead of struct ifreq works too. * But just in case it's not true on some obscure arch... */ r = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)); if (r) bb_perror_msg("can't bind to interface %s", iface); return r; } #else int FAST_FUNC setsockopt_bindtodevice(int fd UNUSED_PARAM, const char *iface UNUSED_PARAM) { bb_error_msg("SO_BINDTODEVICE is not supported on this system"); return -1; } #endif static len_and_sockaddr* get_lsa(int fd, int (*get_name)(int fd, struct sockaddr *addr, socklen_t *addrlen)) { len_and_sockaddr lsa; len_and_sockaddr *lsa_ptr; lsa.len = LSA_SIZEOF_SA; if (get_name(fd, &lsa.u.sa, &lsa.len) != 0) return NULL; lsa_ptr = xzalloc(LSA_LEN_SIZE + lsa.len); if (lsa.len > LSA_SIZEOF_SA) { /* rarely (if ever) happens */ lsa_ptr->len = lsa.len; get_name(fd, &lsa_ptr->u.sa, &lsa_ptr->len); } else { memcpy(lsa_ptr, &lsa, LSA_LEN_SIZE + lsa.len); } return lsa_ptr; } len_and_sockaddr* FAST_FUNC get_sock_lsa(int fd) { return get_lsa(fd, getsockname); } len_and_sockaddr* FAST_FUNC get_peer_lsa(int fd) { return get_lsa(fd, getpeername); } void FAST_FUNC 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)", "can't connect to remote host", inet_ntoa(((struct sockaddr_in *)s_addr)->sin_addr)); bb_perror_msg_and_die("can't 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 FAST_FUNC 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; } /* "New" networking API */ int FAST_FUNC 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 FAST_FUNC set_nport(len_and_sockaddr *lsa, unsigned port) { #if ENABLE_FEATURE_IPV6 if (lsa->u.sa.sa_family == AF_INET6) { lsa->u.sin6.sin6_port = port; return; } #endif if (lsa->u.sa.sa_family == AF_INET) { lsa->u.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, IF_FEATURE_IPV6(sa_family_t af,) int ai_flags) { IF_NOT_FEATURE_IPV6(sa_family_t af = AF_INET;) int rc; len_and_sockaddr *r; struct addrinfo *result = NULL; struct addrinfo *used_res; const char *org_host = host; /* only for error msg */ const char *cp; struct addrinfo hint; if (ENABLE_FEATURE_UNIX_LOCAL && strncmp(host, "local:", 6) == 0) { struct sockaddr_un *sun; r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_un)); r->len = sizeof(struct sockaddr_un); r->u.sa.sa_family = AF_UNIX; sun = (struct sockaddr_un *)&r->u.sa; safe_strncpy(sun->sun_path, host + 6, sizeof(sun->sun_path)); return r; } r = NULL; /* Ugly parsing of host:addr */ if (ENABLE_FEATURE_IPV6 && host[0] == '[') { /* Even uglier parsing of [xx]:nn */ host++; cp = strchr(host, ']'); if (!cp || (cp[1] != ':' && cp[1] != '\0')) { /* Malformed: must be [xx]:nn or [xx] */ bb_error_msg("bad address '%s'", org_host); if (ai_flags & DIE_ON_ERROR) xfunc_die(); 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) { /* points to ":" or "]:" */ int sz = cp - host + 1; host = safe_strncpy(alloca(sz), host, sz); if (ENABLE_FEATURE_IPV6 && *cp != ':') { cp++; /* skip ']' */ if (*cp == '\0') /* [xx] without port */ goto skip; } cp++; /* skip ':' */ port = bb_strtou(cp, NULL, 10); if (errno || (unsigned)port > 0xffff) { bb_error_msg("bad port spec '%s'", org_host); if (ai_flags & DIE_ON_ERROR) xfunc_die(); return NULL; } skip: ; } /* Next two if blocks allow to skip getaddrinfo() * in case host name is a numeric IP(v6) address. * getaddrinfo() initializes DNS resolution machinery, * scans network config and such - tens of syscalls. */ /* If we were not asked specifically for IPv6, * check whether this is a numeric IPv4 */ IF_FEATURE_IPV6(if(af != AF_INET6)) { struct in_addr in4; if (inet_aton(host, &in4) != 0) { r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_in)); r->len = sizeof(struct sockaddr_in); r->u.sa.sa_family = AF_INET; r->u.sin.sin_addr = in4; goto set_port; } } #if ENABLE_FEATURE_IPV6 /* If we were not asked specifically for IPv4, * check whether this is a numeric IPv6 */ if (af != AF_INET) { struct in6_addr in6; if (inet_pton(AF_INET6, host, &in6) > 0) { r = xzalloc(LSA_LEN_SIZE + sizeof(struct sockaddr_in6)); r->len = sizeof(struct sockaddr_in6); r->u.sa.sa_family = AF_INET6; r->u.sin6.sin6_addr = in6; goto set_port; } } #endif memset(&hint, 0 , sizeof(hint)); hint.ai_family = af; /* 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; } used_res = result; #if ENABLE_FEATURE_PREFER_IPV4_ADDRESS while (1) { if (used_res->ai_family == AF_INET) break; used_res = used_res->ai_next; if (!used_res) { used_res = result; break; } } #endif r = xmalloc(LSA_LEN_SIZE + used_res->ai_addrlen); r->len = used_res->ai_addrlen; memcpy(&r->u.sa, used_res->ai_addr, used_res->ai_addrlen); set_port: 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* FAST_FUNC host_and_af2sockaddr(const char *host, int port, sa_family_t af) { return str2sockaddr(host, port, af, 0); } len_and_sockaddr* FAST_FUNC xhost_and_af2sockaddr(const char *host, int port, sa_family_t af) { return str2sockaddr(host, port, af, DIE_ON_ERROR); } #endif len_and_sockaddr* FAST_FUNC host2sockaddr(const char *host, int port) { return str2sockaddr(host, port, AF_UNSPEC, 0); } len_and_sockaddr* FAST_FUNC xhost2sockaddr(const char *host, int port) { return str2sockaddr(host, port, AF_UNSPEC, DIE_ON_ERROR); } len_and_sockaddr* FAST_FUNC xdotted2sockaddr(const char *host, int port) { return str2sockaddr(host, port, AF_UNSPEC, AI_NUMERICHOST | DIE_ON_ERROR); } #undef xsocket_type int FAST_FUNC xsocket_type(len_and_sockaddr **lsap, IF_FEATURE_IPV6(int family,) int sock_type) { IF_NOT_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(LSA_LEN_SIZE + len); lsa->len = len; lsa->u.sa.sa_family = family; *lsap = lsa; return fd; } int FAST_FUNC xsocket_stream(len_and_sockaddr **lsap) { return xsocket_type(lsap, IF_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->u.sa.sa_family, sock_type, 0); } else { fd = xsocket_type(&lsa, IF_FEATURE_IPV6(AF_UNSPEC,) sock_type); set_nport(lsa, htons(port)); } setsockopt_reuseaddr(fd); xbind(fd, &lsa->u.sa, lsa->len); free(lsa); return fd; } int FAST_FUNC create_and_bind_stream_or_die(const char *bindaddr, int port) { return create_and_bind_or_die(bindaddr, port, SOCK_STREAM); } int FAST_FUNC create_and_bind_dgram_or_die(const char *bindaddr, int port) { return create_and_bind_or_die(bindaddr, port, SOCK_DGRAM); } int FAST_FUNC create_and_connect_stream_or_die(const char *peer, int port) { int fd; len_and_sockaddr *lsa; lsa = xhost2sockaddr(peer, port); fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0); setsockopt_reuseaddr(fd); xconnect(fd, &lsa->u.sa, lsa->len); free(lsa); return fd; } int FAST_FUNC xconnect_stream(const len_and_sockaddr *lsa) { int fd = xsocket(lsa->u.sa.sa_family, SOCK_STREAM, 0); xconnect(fd, &lsa->u.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* FAST_FUNC sockaddr2str(const struct sockaddr *sa, int flags) { char host[128]; char serv[16]; int rc; socklen_t salen; if (ENABLE_FEATURE_UNIX_LOCAL && sa->sa_family == AF_UNIX) { struct sockaddr_un *sun = (struct sockaddr_un *)sa; return xasprintf("local:%.*s", (int) sizeof(sun->sun_path), sun->sun_path); } 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* FAST_FUNC xmalloc_sockaddr2host(const struct sockaddr *sa) { return sockaddr2str(sa, 0); } char* FAST_FUNC xmalloc_sockaddr2host_noport(const struct sockaddr *sa) { return sockaddr2str(sa, IGNORE_PORT); } char* FAST_FUNC xmalloc_sockaddr2hostonly_noport(const struct sockaddr *sa) { return sockaddr2str(sa, NI_NAMEREQD | IGNORE_PORT); } char* FAST_FUNC xmalloc_sockaddr2dotted(const struct sockaddr *sa) { return sockaddr2str(sa, NI_NUMERICHOST); } char* FAST_FUNC xmalloc_sockaddr2dotted_noport(const struct sockaddr *sa) { return sockaddr2str(sa, NI_NUMERICHOST | IGNORE_PORT); }