From 9de420c27cbbbd99bedc95782a6937039ff071bb Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Wed, 10 Jan 2007 09:28:01 +0000 Subject: [PATCH] Improve generic ipv4+ipv6 support in libbb. Convert telnet to it. Now this works: telnetd -b [::1]:1234 - bind to IPv6 non-standard port telnet [::1]:1234 - connect to IPv6 non-standard port telnet ::1 1234 - same This does not require ANY ipv6-specific code in applets (no struct sockaddr_in6. In fact, no sockaddr_in, too). --- include/libbb.h | 21 ++- libbb/xconnect.c | 298 ++++++++++++++++++++++++++----------------- networking/telnet.c | 31 ++--- networking/telnetd.c | 2 +- 4 files changed, 204 insertions(+), 148 deletions(-) diff --git a/include/libbb.h b/include/libbb.h index 6f66c8545..16f092f60 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -293,18 +293,17 @@ extern void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen); extern int xconnect_tcp_v4(struct sockaddr_in *s_addr); extern struct hostent *xgethostbyname(const char *name); extern struct hostent *xgethostbyname2(const char *name, int af); -extern int xsocket_stream_ip4or6(sa_family_t *fp); -typedef union { - struct sockaddr sa; - struct sockaddr_in sin; -#if ENABLE_FEATURE_IPV6 - struct sockaddr_in6 sin6; -#endif -} sockaddr_inet; -extern int dotted2sockaddr(const char *dotted, struct sockaddr* sp, int socklen); -extern int create_and_bind_socket_ip4or6(const char *hostaddr, int port); + extern int setsockopt_reuseaddr(int fd); extern int setsockopt_broadcast(int fd); +/* Create server TCP socket bound to bindaddr:port. bindaddr can be NULL, + * numeric IP ("N.N.N.N") or numeric IPv6 address, + * and can have ":PORT" suffix. If no suffix trere, second argument is used */ +extern int create_and_bind_stream_or_die(const char *bindaddr, int port); +/* Create client TCP socket connected to peer:port. Peer cannot be NULL. + * Peer can be numeric IP ("N.N.N.N"), numeric IPv6 address or hostname, + * and can have ":PORT" suffix. If no suffix trere, second argument is used */ +extern int create_and_connect_stream_or_die(const char *peer, int def_port); extern char *xstrdup(const char *s); @@ -506,7 +505,7 @@ USE_DESKTOP(long long) int uncompress(int fd_in, int fd_out); int inflate(int in, int out); -unsigned short bb_lookup_port(const char *port, const char *protocol, unsigned short default_port); +unsigned bb_lookup_port(const char *port, const char *protocol, unsigned default_port); void bb_lookup_host(struct sockaddr_in *s_in, const char *host); int bb_make_directory(char *path, long mode, int flags); diff --git a/libbb/xconnect.c b/libbb/xconnect.c index bc0691531..93c3cd5c6 100644 --- a/libbb/xconnect.c +++ b/libbb/xconnect.c @@ -6,68 +6,9 @@ * */ +#include #include "libbb.h" -/* 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 short bb_lookup_port(const char *port, const char *protocol, unsigned short default_port) -{ - unsigned short port_nr = htons(default_port); - if (port) { - char *endptr; - int old_errno; - long port_long; - - /* 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; - errno = 0; - port_long = strtol(port, &endptr, 10); - if (errno != 0 || *endptr!='\0' || endptr==port || port_long < 0 || port_long > 65535) { - struct servent *tserv = getservbyname(port, protocol); - if (tserv) { - port_nr = tserv->s_port; - } - } else { - port_nr = htons(port_long); - } - errno = old_errno; - } - return port_nr; -} - -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); -} - -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"); - } -} - -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; -} - static const int one = 1; int setsockopt_reuseaddr(int fd) { @@ -78,77 +19,204 @@ int setsockopt_broadcast(int fd) return setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one)); } -int dotted2sockaddr(const char *dotted, struct sockaddr* sp, int socklen) +void xconnect(int s, const struct sockaddr *s_addr, socklen_t addrlen) { - union { - struct in_addr a4; -#if ENABLE_FEATURE_IPV6 - struct in6_addr a6; -#endif - } a; - - /* TODO maybe: port spec? like n.n.n.n:nn */ - -#if ENABLE_FEATURE_IPV6 - if (socklen >= sizeof(struct sockaddr_in6) - && inet_pton(AF_INET6, dotted, &a.a6) > 0 - ) { - ((struct sockaddr_in6*)sp)->sin6_family = AF_INET6; - ((struct sockaddr_in6*)sp)->sin6_addr = a.a6; - /* ((struct sockaddr_in6*)sp)->sin6_port = */ - return 0; /* success */ + 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"); } -#endif - if (socklen >= sizeof(struct sockaddr_in) - && inet_pton(AF_INET, dotted, &a.a4) > 0 - ) { - ((struct sockaddr_in*)sp)->sin_family = AF_INET; - ((struct sockaddr_in*)sp)->sin_addr = a.a4; - /* ((struct sockaddr_in*)sp)->sin_port = */ - return 0; /* success */ - } - return 1; } -int xsocket_stream_ip4or6(sa_family_t *fp) +/* 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 */ + + +/* So far we do not expose struct and helpers to libbb */ +typedef struct len_and_sockaddr { + int len; + union { + struct sockaddr sa; + struct sockaddr_in sin; +#if ENABLE_FEATURE_IPV6 + struct sockaddr_in6 sin6; +#endif + }; +} len_and_sockaddr; +//extern int xsocket_stream_ip4or6(sa_family_t *fp); +//extern len_and_sockaddr* host2sockaddr(const char *host, int def_port); +//extern len_and_sockaddr* dotted2sockaddr(const char *dotted, int def_port); + +/* peer: "1.2.3.4[:port]", "www.google.com[:port]" + * def_port: if neither of above specifies port # + */ +static len_and_sockaddr* str2sockaddr(const char *host, int def_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) { + host = safe_strncpy(alloca(cp - host + 1), host, cp - host); + if (ENABLE_FEATURE_IPV6 && *cp != ':') + cp++; /* skip ']' */ + cp++; /* skip ':' */ + } else { + utoa_to_buf(def_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; +} + +static len_and_sockaddr* host2sockaddr(const char *host, int def_port) +{ + return str2sockaddr(host, def_port, 0); +} + +static len_and_sockaddr* dotted2sockaddr(const char *host, int def_port) +{ + return str2sockaddr(host, def_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); - if (fp) *fp = AF_INET6; - if (fd < 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); - if (fp) *fp = AF_INET; - } + 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_socket_ip4or6(const char *hostaddr, int port) +int create_and_bind_stream_or_die(const char *bindaddr, int port) { int fd; - sockaddr_inet sa; + len_and_sockaddr *lsa; - memset(&sa, 0, sizeof(sa)); - if (hostaddr) { - if (dotted2sockaddr(hostaddr, &sa.sa, sizeof(sa))) - bb_error_msg_and_die("bad address '%s'", hostaddr); + if (bindaddr) { + 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(sa.sa.sa_family, SOCK_STREAM, 0); - } else - fd = xsocket_stream_ip4or6(&sa.sa.sa_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); - - /* if (port >= 0) { */ -#if ENABLE_FEATURE_IPV6 - if (sa.sa.sa_family == AF_INET6 /* && !sa.sin6.sin6_port */) - sa.sin6.sin6_port = htons(port); -#endif - if (sa.sa.sa_family == AF_INET /* && !sa.sin.sin_port */) - sa.sin.sin_port = htons(port); - /* } */ - - xbind(fd, &sa.sa, sizeof(sa)); + 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; } diff --git a/networking/telnet.c b/networking/telnet.c index e65b6918d..5ca64e133 100644 --- a/networking/telnet.c +++ b/networking/telnet.c @@ -22,15 +22,7 @@ */ #include -#include -#include -#include -#include -#include -#include #include -#include -#include #include #include "busybox.h" @@ -593,8 +585,9 @@ static void cookmode(void) int telnet_main(int argc, char** argv) { + char *host; + int port; int len; - struct sockaddr_in s_in; #ifdef USE_POLL struct pollfd ufds[2]; #else @@ -610,11 +603,10 @@ int telnet_main(int argc, char** argv) ttype = getenv("TERM"); #endif - memset(&G, 0, sizeof G); + /* memset(&G, 0, sizeof G); - already is */ if (tcgetattr(0, &G.termios_def) >= 0) { G.do_termios = 1; - G.termios_raw = G.termios_def; cfmakeraw(&G.termios_raw); } @@ -627,19 +619,18 @@ int telnet_main(int argc, char** argv) autologin = getenv("USER"); if (optind < argc) { - bb_lookup_host(&s_in, argv[optind++]); - s_in.sin_port = bb_lookup_port((optind < argc) ? argv[optind++] : + host = argv[optind++]; + port = bb_lookup_port((optind < argc) ? argv[optind++] : "telnet", "tcp", 23); if (optind < argc) bb_show_usage(); } else bb_show_usage(); #else - bb_lookup_host(&s_in, argv[1]); - s_in.sin_port = bb_lookup_port((argc == 3) ? argv[2] : "telnet", "tcp", 23); + host = argv[1]; + port = bb_lookup_port((argc > 2) ? argv[2] : "telnet", "tcp", 23); #endif - - G.netfd = xconnect_tcp_v4(&s_in); + G.netfd = create_and_connect_stream_or_die(host, port); setsockopt(G.netfd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof one); @@ -655,8 +646,7 @@ int telnet_main(int argc, char** argv) maxfd = G.netfd + 1; #endif - while (1) - { + while (1) { #ifndef USE_POLL fd_set rfds = readfds; @@ -700,8 +690,7 @@ int telnet_main(int argc, char** argv) { len = read(G.netfd, G.buf, DATABUFSIZE); - if (len <= 0) - { + if (len <= 0) { WriteCS(1, "Connection closed by foreign host.\r\n"); doexit(1); } diff --git a/networking/telnetd.c b/networking/telnetd.c index 604f65c91..a0ee2c345 100644 --- a/networking/telnetd.c +++ b/networking/telnetd.c @@ -414,7 +414,7 @@ telnetd_main(int argc, char **argv) if (IS_INETD) { sessions = make_new_session(0, 1); } else { - master_fd = create_and_bind_socket_ip4or6(opt_bindaddr, portnbr); + master_fd = create_and_bind_stream_or_die(opt_bindaddr, portnbr); xlisten(master_fd, 1); if (!(opt & OPT_FOREGROUND)) xdaemon(0, 0);