/* -*- c-file-style: "linux" -*- Copyright (C) 1998-2001 by Andrew Tridgell Copyright (C) 2001 by Martin Pool This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* socket functions used in rsync */ #include "rsync.h" /* Establish a proxy connection on an open socket to a web roxy by * using the 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)) { rprintf(FERROR, "failed to write to proxy: %s\n", strerror(errno)); return -1; } for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; cp++) { if (read(fd, cp, 1) != 1) { rprintf(FERROR, "failed to read from proxy: %s\n", strerror(errno)); return -1; } if (*cp == '\n') break; } if (*cp != '\n') cp++; *cp-- = '\0'; if (*cp == '\r') *cp = '\0'; if (strncmp(buffer, "HTTP/", 5) != 0) { rprintf(FERROR, "bad response from proxy - %s\n", buffer); return -1; } for (cp = &buffer[5]; isdigit(*cp) || (*cp == '.'); cp++) ; while (*cp == ' ') cp++; if (*cp != '2') { rprintf(FERROR, "bad response from proxy - %s\n", buffer); return -1; } /* throw away the rest of the HTTP header */ while (1) { for (cp = buffer; cp < &buffer[sizeof(buffer) - 1]; cp++) { if (read(fd, cp, 1) != 1) { rprintf(FERROR, "failed to read from proxy: %s\n", strerror(errno)); return -1; } if (*cp == '\n') break; } if ((cp > buffer) && (*cp == '\n')) cp--; if ((cp == buffer) && ((*cp == '\n') || (*cp == '\r'))) break; } return 0; } /* open a socket to a tcp remote host with the specified port based on code from Warren proxy support by Stephen Rothwell */ int open_socket_out(char *host, int port, struct in_addr *address) { int type = SOCK_STREAM; struct sockaddr_in sock_out; struct sockaddr_in sock; int res; struct hostent *hp; char *h; unsigned p; int proxied = 0; char buffer[1024]; char *cp; /* if we have a RSYNC_PROXY env variable then redirect our * connetcion via a web proxy at the given address. The format * is hostname:port */ h = getenv("RSYNC_PROXY"); proxied = (h != NULL) && (*h != '\0'); if (proxied) { strlcpy(buffer, h, sizeof(buffer)); cp = strchr(buffer, ':'); if (cp == NULL) { rprintf(FERROR, "invalid proxy specification: should be HOST:PORT\n"); return -1; } *cp++ = '\0'; p = atoi(cp); h = buffer; } else { h = host; p = port; } res = socket(PF_INET, type, 0); if (res == -1) { return -1; } hp = gethostbyname(h); if (!hp) { rprintf(FERROR,"unknown host: \"%s\"\n", h); close(res); return -1; } memcpy(&sock_out.sin_addr, hp->h_addr, hp->h_length); sock_out.sin_port = htons(p); sock_out.sin_family = PF_INET; if (address) { sock.sin_addr = *address; sock.sin_port = 0; sock.sin_family = hp->h_addrtype; bind(res, (struct sockaddr * ) &sock,sizeof(sock)); } if (connect(res,(struct sockaddr *)&sock_out,sizeof(sock_out))) { rprintf(FERROR,"failed to connect to %s - %s\n", h, strerror(errno)); close(res); return -1; } if (proxied && establish_proxy_connection(res, host, port) != 0) { close(res); return -1; } return res; } /**************************************************************************** open a socket of the specified type, port and address for incoming data ****************************************************************************/ static int open_socket_in(int type, int port, struct in_addr *address) { struct sockaddr_in sock; int res; int one=1; memset((char *)&sock,0,sizeof(sock)); sock.sin_port = htons(port); sock.sin_family = AF_INET; if (address) { sock.sin_addr = *address; } else { sock.sin_addr.s_addr = INADDR_ANY; } res = socket(AF_INET, type, 0); if (res == -1) { rprintf(FERROR,"socket failed: %s\n", strerror(errno)); return -1; } setsockopt(res,SOL_SOCKET,SO_REUSEADDR,(char *)&one,sizeof(one)); /* now we've got a socket - we need to bind it */ if (bind(res, (struct sockaddr * ) &sock,sizeof(sock)) == -1) { rprintf(FERROR,"bind failed on port %d: %s\n", port, strerror(errno)); if (errno == EACCES && port < 1024) { rprintf(FERROR, "Note: you must be root to bind " "to low-numbered ports"); } close(res); return -1; } return res; } /* * Determine if a file descriptor is in fact a socket */ int is_a_socket(int fd) { int v; socklen_t l; l = sizeof(int); /* Parameters to getsockopt, setsockopt etc are very * unstandardized across platforms, so don't be surprised if * there are compiler warnings on e.g. SCO OpenSwerver or AIX. * It seems they all eventually get the right idea. * * Debian says: ``The fifth argument of getsockopt and * setsockopt is in reality an int [*] (and this is what BSD * 4.* and libc4 and libc5 have). Some POSIX confusion * resulted in the present socklen_t. The draft standard has * not been adopted yet, but glibc2 already follows it and * also has socklen_t [*]. See also accept(2).'' * * We now return to your regularly scheduled programming. */ return(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&v, &l) == 0); } void start_accept_loop(int port, int (*fn)(int )) { int s; extern struct in_addr socket_address; /* open an incoming socket */ s = open_socket_in(SOCK_STREAM, port, &socket_address); if (s == -1) exit_cleanup(RERR_SOCKETIO); /* ready to listen */ if (listen(s, 5) == -1) { close(s); exit_cleanup(RERR_SOCKETIO); } /* now accept incoming connections - forking a new process for each incoming connection */ while (1) { fd_set fds; int fd; struct sockaddr addr; socklen_t in_addrlen = sizeof(addr); /* close log file before the potentially very long select so file can be trimmed by another process instead of growing forever */ log_close(); FD_ZERO(&fds); FD_SET(s, &fds); if (select(s+1, &fds, NULL, NULL, NULL) != 1) { continue; } if(!FD_ISSET(s, &fds)) continue; /* See note above prototypes. */ fd = accept(s,&addr, &in_addrlen); if (fd == -1) continue; signal(SIGCHLD, SIG_IGN); /* we shouldn't have any children left hanging around but I have had reports that on Digital Unix zombies are produced, so this ensures that they are reaped */ #ifdef WNOHANG while (waitpid(-1, NULL, WNOHANG) > 0); #endif if (fork()==0) { close(s); /* open log file in child before possibly giving up privileges */ log_open(); _exit(fn(fd)); } close(fd); } } enum SOCK_OPT_TYPES {OPT_BOOL,OPT_INT,OPT_ON}; struct { char *name; int level; int option; int value; int opttype; } socket_options[] = { {"SO_KEEPALIVE", SOL_SOCKET, SO_KEEPALIVE, 0, OPT_BOOL}, {"SO_REUSEADDR", SOL_SOCKET, SO_REUSEADDR, 0, OPT_BOOL}, {"SO_BROADCAST", SOL_SOCKET, SO_BROADCAST, 0, OPT_BOOL}, #ifdef TCP_NODELAY {"TCP_NODELAY", IPPROTO_TCP, TCP_NODELAY, 0, OPT_BOOL}, #endif #ifdef IPTOS_LOWDELAY {"IPTOS_LOWDELAY", IPPROTO_IP, IP_TOS, IPTOS_LOWDELAY, OPT_ON}, #endif #ifdef IPTOS_THROUGHPUT {"IPTOS_THROUGHPUT", IPPROTO_IP, IP_TOS, IPTOS_THROUGHPUT, OPT_ON}, #endif #ifdef SO_SNDBUF {"SO_SNDBUF", SOL_SOCKET, SO_SNDBUF, 0, OPT_INT}, #endif #ifdef SO_RCVBUF {"SO_RCVBUF", SOL_SOCKET, SO_RCVBUF, 0, OPT_INT}, #endif #ifdef SO_SNDLOWAT {"SO_SNDLOWAT", SOL_SOCKET, SO_SNDLOWAT, 0, OPT_INT}, #endif #ifdef SO_RCVLOWAT {"SO_RCVLOWAT", SOL_SOCKET, SO_RCVLOWAT, 0, OPT_INT}, #endif #ifdef SO_SNDTIMEO {"SO_SNDTIMEO", SOL_SOCKET, SO_SNDTIMEO, 0, OPT_INT}, #endif #ifdef SO_RCVTIMEO {"SO_RCVTIMEO", SOL_SOCKET, SO_RCVTIMEO, 0, OPT_INT}, #endif {NULL,0,0,0,0}}; /**************************************************************************** set user socket options ****************************************************************************/ void set_socket_options(int fd, char *options) { char *tok; if (!options || !*options) return; options = strdup(options); if (!options) out_of_memory("set_socket_options"); for (tok=strtok(options, " \t,"); tok; tok=strtok(NULL," \t,")) { int ret=0,i; int value = 1; char *p; int got_value = 0; if ((p = strchr(tok,'='))) { *p = 0; value = atoi(p+1); got_value = 1; } for (i=0;socket_options[i].name;i++) if (strcmp(socket_options[i].name,tok)==0) break; if (!socket_options[i].name) { rprintf(FERROR,"Unknown socket option %s\n",tok); continue; } switch (socket_options[i].opttype) { case OPT_BOOL: case OPT_INT: ret = setsockopt(fd,socket_options[i].level, socket_options[i].option,(char *)&value,sizeof(int)); break; case OPT_ON: if (got_value) rprintf(FERROR,"syntax error - %s does not take a value\n",tok); { int on = socket_options[i].value; ret = setsockopt(fd,socket_options[i].level, socket_options[i].option,(char *)&on,sizeof(int)); } break; } if (ret != 0) rprintf(FERROR, "failed to set socket option %s: %s\n", tok, strerror(errno)); } free(options); } /**************************************************************************** become a daemon, discarding the controlling terminal ****************************************************************************/ void become_daemon(void) { int i; if (fork()) { _exit(0); } /* detach from the terminal */ #ifdef HAVE_SETSID setsid(); #else #ifdef TIOCNOTTY i = open("/dev/tty", O_RDWR); if (i >= 0) { ioctl(i, (int) TIOCNOTTY, (char *)0); close(i); } #endif /* TIOCNOTTY */ #endif /* make sure that stdin, stdout an stderr don't stuff things up (library functions, for example) */ for (i=0;i<3;i++) { close(i); open("/dev/null", O_RDWR); } } /******************************************************************* return the IP addr of the client as a string ******************************************************************/ char *client_addr(int fd) { struct sockaddr sa; struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa); socklen_t length = sizeof(sa); static char addr_buf[100]; static int initialised; if (initialised) return addr_buf; initialised = 1; if (getpeername(fd, &sa, &length)) { exit_cleanup(RERR_SOCKETIO); } strlcpy(addr_buf,(char *)inet_ntoa(sockin->sin_addr), sizeof(addr_buf)); return addr_buf; } /******************************************************************* return the DNS name of the client ******************************************************************/ char *client_name(int fd) { struct sockaddr sa; struct sockaddr_in *sockin = (struct sockaddr_in *) (&sa); socklen_t length = sizeof(sa); static char name_buf[100]; struct hostent *hp; char **p; char *def = "UNKNOWN"; static int initialised; if (initialised) return name_buf; initialised = 1; strcpy(name_buf,def); if (getpeername(fd, &sa, &length)) { exit_cleanup(RERR_SOCKETIO); } /* Look up the remote host name. */ if ((hp = gethostbyaddr((char *) &sockin->sin_addr, sizeof(sockin->sin_addr), AF_INET))) { strlcpy(name_buf,(char *)hp->h_name,sizeof(name_buf)); } /* do a forward lookup as well to prevent spoofing */ hp = gethostbyname(name_buf); if (!hp) { strcpy (name_buf,def); rprintf (FERROR, "reverse name lookup for \"%s\" failed\n", name_buf); } else { for (p=hp->h_addr_list;*p;p++) { if (memcmp(*p, &sockin->sin_addr, hp->h_length) == 0) { break; } } if (!*p) { strcpy(name_buf,def); rprintf(FERROR,"reverse name lookup mismatch - spoofed address?\n"); } } return name_buf; } /** Convert a string to an IP address. The string can be a name or dotted decimal number. Returns a pointer to a static in_addr struct -- if you call this more than once then you should copy it. */ struct in_addr *ip_address(const char *str) { static struct in_addr ret; struct hostent *hp; if (!str) { rprintf (FERROR, "ip_address received NULL name\n"); return NULL; } /* try as an IP address */ if (inet_aton(str, &ret) != 0) { return &ret; } /* otherwise assume it's a network name of some sort and use gethostbyname */ if ((hp = gethostbyname (str)) == 0) { rprintf(FERROR, "gethostbyname failed for \"%s\": unknown host?\n",str); return NULL; } if (hp->h_addr == NULL) { rprintf(FERROR, "gethostbyname: host address is invalid for host \"%s\"\n",str); return NULL; } if (hp->h_length > sizeof ret) { rprintf(FERROR, "gethostbyname: host address for \"%s\" is too large\n", str); return NULL; } if (hp->h_addrtype != AF_INET) { rprintf (FERROR, "gethostname: host address for \"%s\" is not IPv4\n", str); return NULL; } /* This is kind of difficult. The only field in ret is s_addr, which is the IP address as a 32-bit int. On UNICOS, s_addr is in fact a *bitfield* for reasons best know to Cray. This means we can't memcpy in to it. On the other hand, h_addr is a char*, so we can't just assign. Since there's meant to be only one field inside the in_addr structure we will try just copying over the top and see how that goes. */ memcpy (&ret, hp->h_addr, hp->h_length); return &ret; }