/* vi: set sw=4 ts=4: */ /* * Utility routines. * * Connect to host at port using address resolution from getaddrinfo * */ #include #include "libbb.h" static const int one = 1; int setsockopt_reuseaddr(int fd) { return setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); } int setsockopt_broadcast(int fd) { return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one)); } 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 network byte ordered 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 = htons(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); if (tserv) port_nr = tserv->s_port; } else { port_nr = htons(port_nr); } errno = old_errno; } return 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 */ //extern int xsocket_stream_ip4or6(sa_family_t *fp); //extern len_and_sockaddr* dotted2sockaddr(const char *dotted, int def_port); /* peer: "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, 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; char service[sizeof(int)*3 + 1]; 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 ':' */ } else { utoa_to_buf(port, service, sizeof(service)); cp = service; } memset(&hint, 0 , sizeof(hint)); /* hint.ai_family = AF_UNSPEC; - zero anyway */ #if !ENABLE_FEATURE_IPV6 hint.ai_family = AF_INET; /* do not try to find IPv6 */ #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 | AI_NUMERICSERV; rc = getaddrinfo(host, cp, &hint, &result); if (rc || !result) bb_error_msg_and_die("bad address '%s'", org_host); r = xmalloc(offsetof(len_and_sockaddr, sa) + result->ai_addrlen); r->len = result->ai_addrlen; memcpy(&r->sa, result->ai_addr, result->ai_addrlen); freeaddrinfo(result); return r; } len_and_sockaddr* host2sockaddr(const char *host, int port) { return str2sockaddr(host, port, 0); } static len_and_sockaddr* dotted2sockaddr(const char *host, int port) { return str2sockaddr(host, port, NI_NUMERICHOST); } static int xsocket_stream_ip4or6(len_and_sockaddr *lsa) { int fd; #if ENABLE_FEATURE_IPV6 fd = socket(AF_INET6, SOCK_STREAM, 0); lsa->sa.sa_family = AF_INET6; lsa->len = sizeof(struct sockaddr_in6); if (fd >= 0) return fd; #endif fd = xsocket(AF_INET, SOCK_STREAM, 0); lsa->sa.sa_family = AF_INET; lsa->len = sizeof(struct sockaddr_in); return fd; } int create_and_bind_stream_or_die(const char *bindaddr, int port) { int fd; len_and_sockaddr *lsa; if (bindaddr && bindaddr[0]) { lsa = dotted2sockaddr(bindaddr, port); /* currently NULL check is in str2sockaddr */ //if (!lsa) // bb_error_msg_and_die("bad address '%s'", bindaddr); /* user specified bind addr dictates family */ fd = xsocket(lsa->sa.sa_family, SOCK_STREAM, 0); } else { lsa = xzalloc(offsetof(len_and_sockaddr, sa) + USE_FEATURE_IPV6(sizeof(struct sockaddr_in6)) SKIP_FEATURE_IPV6(sizeof(struct sockaddr_in)) ); fd = xsocket_stream_ip4or6(lsa); } setsockopt_reuseaddr(fd); xbind(fd, &lsa->sa, lsa->len); free(lsa); return fd; } int create_and_connect_stream_or_die(const char *peer, int port) { int fd; len_and_sockaddr *lsa; lsa = host2sockaddr(peer, port); /* currently NULL check is in str2sockaddr */ //if (!lsa) // bb_error_msg_and_die("bad address '%s'", peer); fd = xsocket(lsa->sa.sa_family, SOCK_STREAM, 0); setsockopt_reuseaddr(fd); xconnect(fd, &lsa->sa, lsa->len); free(lsa); return fd; }