X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/9a5a86734fdebb816d81b3276a82b8befc65a740..32f761755e2cfee243a1513c9ea9871586463fa6:/socket.c diff --git a/socket.c b/socket.c index 137d4800..bb7acc06 100644 --- a/socket.c +++ b/socket.c @@ -33,25 +33,18 @@ #include "rsync.h" -static int lookup_name(const struct sockaddr_storage *ss, - socklen_t ss_len, - char *name_buf, size_t name_buf_len, - char *port_buf, size_t port_buf_len); - -static int check_name(const struct sockaddr_storage *ss, - socklen_t ss_len, - const char *name_buf, - const char *port_buf); - -/* Establish a proxy connection on an open socket to a web roxy by - * using the CONNECT method. */ + +/** + * Establish a proxy connection on an open socket to a web proxy by + * using the HTTP CONNECT method. + **/ static int establish_proxy_connection(int fd, char *host, int port) { char buffer[1024]; char *cp; snprintf(buffer, sizeof(buffer), "CONNECT %s:%d HTTP/1.0\r\n\r\n", host, port); - if (write(fd, buffer, strlen(buffer)) != strlen(buffer)) { + if (write(fd, buffer, strlen(buffer)) != (int) strlen(buffer)) { rprintf(FERROR, "failed to write to proxy: %s\n", strerror(errno)); return -1; @@ -77,7 +70,7 @@ static int establish_proxy_connection(int fd, char *host, int port) buffer); return -1; } - for (cp = &buffer[5]; isdigit(*cp) || (*cp == '.'); cp++) + for (cp = &buffer[5]; isdigit(* (unsigned char *) cp) || (*cp == '.'); cp++) ; while (*cp == ' ') cp++; @@ -131,12 +124,14 @@ int try_bind_local(int s, for (r = bres_all; r; r = r->ai_next) { if (bind(s, r->ai_addr, r->ai_addrlen) == -1) continue; + freeaddrinfo(bres_all); return s; } /* no error message; there might be some problem that allows * creation of the socket but not binding, perhaps if the * machine has no ipv6 address of this name. */ + freeaddrinfo(bres_all); return -1; } @@ -191,6 +186,10 @@ int open_socket_out(char *host, int port, const char *bind_address, *cp++ = '\0'; strcpy(portbuf, cp); h = buffer; + if (verbose >= 2) { + rprintf(FINFO, "connection via http proxy %s port %s\n", + h, portbuf); + } } else { snprintf(portbuf, sizeof(portbuf), "%d", port); h = host; @@ -334,7 +333,8 @@ static int open_socket_in(int type, int port, const char *bind_address, close(s); continue; } - + + freeaddrinfo(all_ai); return s; } @@ -396,6 +396,7 @@ void start_accept_loop(int port, int (*fn)(int )) for each incoming connection */ while (1) { fd_set fds; + pid_t pid; int fd; struct sockaddr_storage addr; socklen_t addrlen = sizeof addr; @@ -427,15 +428,26 @@ void start_accept_loop(int port, int (*fn)(int )) while (waitpid(-1, NULL, WNOHANG) > 0); #endif - if (fork()==0) { + if ((pid = fork()) == 0) { close(s); /* open log file in child before possibly giving up privileges */ log_open(); _exit(fn(fd)); + } else if (pid < 0) { + rprintf(FERROR, + RSYNC_NAME + ": could not create child server process: %s\n", + strerror(errno)); + close(fd); + /* This might have happened because we're + * overloaded. Sleep briefly before trying to + * accept again. */ + sleep(2); + } else { + /* Parent doesn't need this fd anymore. */ + close(fd); } - - close(fd); } } @@ -484,9 +496,9 @@ struct -/**************************************************************************** -set user socket options -****************************************************************************/ +/** + * Set user socket options + **/ void set_socket_options(int fd, char *options) { char *tok; @@ -544,9 +556,9 @@ void set_socket_options(int fd, char *options) free(options); } -/**************************************************************************** -become a daemon, discarding the controlling terminal -****************************************************************************/ +/** + * Become a daemon, discarding the controlling terminal + **/ void become_daemon(void) { int i; @@ -575,182 +587,16 @@ void become_daemon(void) } } -/** - * Return the IP addr of the client as a string - **/ -char *client_addr(int fd) -{ - struct sockaddr_storage ss; - socklen_t length = sizeof ss; - static char addr_buf[100]; - static int initialised; - - if (initialised) return addr_buf; - - initialised = 1; - - if (getpeername(fd, (struct sockaddr *)&ss, &length)) { - exit_cleanup(RERR_SOCKETIO); - } - - getnameinfo((struct sockaddr *)&ss, length, - addr_buf, sizeof(addr_buf), NULL, 0, NI_NUMERICHOST); - return addr_buf; -} - - -static int get_sockaddr_family(const struct sockaddr_storage *ss) -{ - return ((struct sockaddr *) ss)->sa_family; -} - - -/** - * Return the DNS name of the client. - * - * The name is statically cached so that repeated lookups are quick, - * so there is a limit of one lookup per customer. - **/ -char *client_name(int fd) -{ - struct sockaddr_storage ss; - socklen_t ss_len = sizeof ss; - static char name_buf[100]; - static char port_buf[100]; - static int initialised; - - if (initialised) return name_buf; - - initialised = 1; - - if (getpeername(fd, (struct sockaddr *)&ss, &ss_len)) { - /* FIXME: Can we really not continue? */ - rprintf(FERROR, RSYNC_NAME ": getpeername on fd%d failed: %s\n", - fd, strerror(errno)); - exit_cleanup(RERR_SOCKETIO); - } - - if (!lookup_name(&ss, ss_len, name_buf, sizeof name_buf, port_buf, sizeof port_buf)) - check_name(&ss, ss_len, name_buf, port_buf); - - return name_buf; -} - /** - * Look up a name from @p ss into @p name_buf. + * This is like socketpair but uses tcp. It is used by the Samba + * regression test code. + * + * The function guarantees that nobody else can attach to the socket, + * or if they do that this function fails and the socket gets closed + * returns 0 on success, -1 on failure the resulting file descriptors + * are symmetrical. **/ -static int lookup_name(const struct sockaddr_storage *ss, - socklen_t ss_len, - char *name_buf, size_t name_buf_len, - char *port_buf, size_t port_buf_len) -{ - int name_err; - const char *def = "UNKNOWN"; - -#ifdef INET6 - if (get_sockaddr_family(ss) == AF_INET6 && - IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)ss)->sin6_addr)) { - /* OK, so ss is in the IPv6 family, but it is really - * an IPv4 address: something like - * "::ffff:10.130.1.2". If we use it as-is, then the - * reverse lookup might fail or perhaps something else - * bad might happen. So instead we convert it to an - * equivalent address in the IPv4 address family. */ - struct sockaddr_in6 sin6; - struct sockaddr_in *sin; - - memcpy(&sin6, ss, sizeof(sin6)); - sin = (struct sockaddr_in *)ss; - memset(sin, 0, sizeof(*sin)); - sin->sin_family = AF_INET; - ss_len = sizeof(struct sockaddr_in); -#ifdef HAVE_SOCKADDR_LEN - sin->sin_len = ss_len; -#endif - sin->sin_port = sin6.sin6_port; - /* FIXME: Isn't there a macro we can use here rather - * than grovelling through the struct? It might be - * wrong on some systems. */ - memcpy(&sin->sin_addr, &sin6.sin6_addr.s6_addr[12], - sizeof(sin->sin_addr)); - } -#endif - - /* reverse lookup */ - if (!(name_err = getnameinfo((struct sockaddr *) ss, ss_len, - name_buf, name_buf_len, - port_buf, port_buf_len, - NI_NAMEREQD | NI_NUMERICSERV))) { - strcpy(name_buf, def); - rprintf(FERROR, RSYNC_NAME ": reverse name lookup failed: %s\n", - gai_strerror(name_err)); - return name_err; - } - - return 0; -} - - - -/* Do a forward lookup on name_buf and make sure it corresponds to ss - * -- otherwise we may be being spoofed. If we suspect we are, then - * we don't abort the connection but just emit a warning. */ -static int check_name(const struct sockaddr_storage *ss, - socklen_t ss_len, - const char *name_buf, - const char *port_buf) -{ - struct addrinfo hints, *res, *res0; - int error; - - memset(&hints, 0, sizeof(hints)); - hints.ai_family = PF_UNSPEC; - hints.ai_flags = AI_CANONNAME; - hints.ai_socktype = SOCK_STREAM; - error = getaddrinfo(name_buf, port_buf, &hints, &res0); - if (error) { - /* We still use the name found by the reverse lookup, - * but emit a warning. */ - rprintf(FERROR, - RSYNC_NAME ": forward name lookup for %s:%s failed: %s\n", - name_buf, port_buf, - gai_strerror(error)); - return error; - } - - - /* We expect that one of the results will be the same as ss. */ - for (res = res0; res; res = res->ai_next) { - if (res->ai_family != get_sockaddr_family(ss)) - continue; - if (res->ai_addrlen != ss_len) - continue; - if (memcmp(res->ai_addr, ss, res->ai_addrlen) == 0) - break; - } - - if (res == NULL) { - /* We hit the end of the list without finding an - * address that was the same as ss. */ - rprintf(FERROR, RSYNC_NAME - ": no address record for \"%s\" corresponds to peer name: spoofed address?\n", - name_buf); - } - - freeaddrinfo(res0); - return 0; -} - - -/******************************************************************* -this is like socketpair but uses tcp. It is used by the Samba -regression test code -The function guarantees that nobody else can attach to the socket, -or if they do that this function fails and the socket gets closed -returns 0 on success, -1 on failure -the resulting file descriptors are symmetrical - ******************************************************************/ static int socketpair_tcp(int fd[2]) { int listener; @@ -766,7 +612,7 @@ static int socketpair_tcp(int fd[2]) if ((listener = socket(PF_INET, SOCK_STREAM, 0)) == -1) goto failed; memset(&sock2, 0, sizeof(sock2)); -#ifdef HAVE_SOCK_SIN_LEN +#ifdef HAVE_SOCKADDR_LEN sock2.sin_len = sizeof(sock2); #endif sock2.sin_family = PF_INET; @@ -810,16 +656,20 @@ static int socketpair_tcp(int fd[2]) } -/******************************************************************* -run a program on a local tcp socket, this is used to launch smbd -when regression testing -the return value is a socket which is attached to a subprocess -running "prog". stdin and stdout are attached. stderr is left -attached to the original stderr - ******************************************************************/ + +/** + * Run a program on a local tcp socket, so that we can talk to it's + * stdin and stdout. This is used to fake a connection to a daemon + * for testing -- not for the normal case of running SSH. + * + * @return a socket which is attached to a subprocess running + * "prog". stdin and stdout are attached. stderr is left attached to + * the original stderr + **/ int sock_exec(const char *prog) { int fd[2]; + if (socketpair_tcp(fd) != 0) { rprintf (FERROR, RSYNC_NAME ": socketpair_tcp failed (%s)\n", @@ -832,10 +682,12 @@ int sock_exec(const char *prog) close(1); dup(fd[1]); dup(fd[1]); - if (verbose > 3) + if (verbose > 3) { + /* Can't use rprintf because we've forked. */ fprintf (stderr, RSYNC_NAME ": execute socket program \"%s\"\n", prog); + } exit (system (prog)); } close (fd[1]);