/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2012, Daniel Stenberg, , et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at http://curl.haxx.se/docs/copyright.html. * * You may opt to use, copy, modify, merge, publish, distribute and/or sell * copies of the Software, and permit persons to whom the Software is * furnished to do so, under the terms of the COPYING file. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ***************************************************************************/ #include "server_setup.h" /* Purpose * * 1. Accept a TCP connection on a custom port (ipv4 or ipv6), or connect * to a given (localhost) port. * * 2. Get commands on STDIN. Pass data on to the TCP stream. * Get data from TCP stream and pass on to STDOUT. * * This program is made to perform all the socket/stream/connection stuff for * the test suite's (perl) FTP server. Previously the perl code did all of * this by its own, but I decided to let this program do the socket layer * because of several things: * * o We want the perl code to work with rather old perl installations, thus * we cannot use recent perl modules or features. * * o We want IPv6 support for systems that provide it, and doing optional IPv6 * support in perl seems if not impossible so at least awkward. * * o We want FTP-SSL support, which means that a connection that starts with * plain sockets needs to be able to "go SSL" in the midst. This would also * require some nasty perl stuff I'd rather avoid. * * (Source originally based on sws.c) */ /* * Signal handling notes for sockfilt * ---------------------------------- * * This program is a single-threaded process. * * This program is intended to be highly portable and as such it must be kept as * simple as possible, due to this the only signal handling mechanisms used will * be those of ANSI C, and used only in the most basic form which is good enough * for the purpose of this program. * * For the above reason and the specific needs of this program signals SIGHUP, * SIGPIPE and SIGALRM will be simply ignored on systems where this can be done. * If possible, signals SIGINT and SIGTERM will be handled by this program as an * indication to cleanup and finish execution as soon as possible. This will be * achieved with a single signal handler 'exit_signal_handler' for both signals. * * The 'exit_signal_handler' upon the first SIGINT or SIGTERM received signal * will just set to one the global var 'got_exit_signal' storing in global var * 'exit_signal' the signal that triggered this change. * * Nothing fancy that could introduce problems is used, the program at certain * points in its normal flow checks if var 'got_exit_signal' is set and in case * this is true it just makes its way out of loops and functions in structured * and well behaved manner to achieve proper program cleanup and termination. * * Even with the above mechanism implemented it is worthwile to note that other * signals might still be received, or that there might be systems on which it * is not possible to trap and ignore some of the above signals. This implies * that for increased portability and reliability the program must be coded as * if no signal was being ignored or handled at all. Enjoy it! */ #ifdef HAVE_SIGNAL_H #include #endif #ifdef HAVE_NETINET_IN_H #include #endif #ifdef HAVE_ARPA_INET_H #include #endif #ifdef HAVE_NETDB_H #include #endif #ifdef WIN32 #include #include #endif #define ENABLE_CURLX_PRINTF /* make the curlx header define all printf() functions to use the curlx_* versions instead */ #include "curlx.h" /* from the private lib dir */ #include "getpart.h" #include "inet_pton.h" #include "util.h" #include "server_sockaddr.h" /* include memdebug.h last */ #include "memdebug.h" #define DEFAULT_PORT 8999 #ifndef DEFAULT_LOGFILE #define DEFAULT_LOGFILE "log/sockfilt.log" #endif const char *serverlogfile = DEFAULT_LOGFILE; static bool verbose = FALSE; static bool bind_only = FALSE; #ifdef ENABLE_IPV6 static bool use_ipv6 = FALSE; #endif static const char *ipv_inuse = "IPv4"; static unsigned short port = DEFAULT_PORT; static unsigned short connectport = 0; /* if non-zero, we activate this mode */ enum sockmode { PASSIVE_LISTEN, /* as a server waiting for connections */ PASSIVE_CONNECT, /* as a server, connected to a client */ ACTIVE, /* as a client, connected to a server */ ACTIVE_DISCONNECT /* as a client, disconnected from server */ }; /* do-nothing macro replacement for systems which lack siginterrupt() */ #ifndef HAVE_SIGINTERRUPT #define siginterrupt(x,y) do {} while(0) #endif /* vars used to keep around previous signal handlers */ typedef RETSIGTYPE (*SIGHANDLER_T)(int); #ifdef SIGHUP static SIGHANDLER_T old_sighup_handler = SIG_ERR; #endif #ifdef SIGPIPE static SIGHANDLER_T old_sigpipe_handler = SIG_ERR; #endif #ifdef SIGALRM static SIGHANDLER_T old_sigalrm_handler = SIG_ERR; #endif #ifdef SIGINT static SIGHANDLER_T old_sigint_handler = SIG_ERR; #endif #ifdef SIGTERM static SIGHANDLER_T old_sigterm_handler = SIG_ERR; #endif /* var which if set indicates that the program should finish execution */ SIG_ATOMIC_T got_exit_signal = 0; /* if next is set indicates the first signal handled in exit_signal_handler */ static volatile int exit_signal = 0; /* signal handler that will be triggered to indicate that the program should finish its execution in a controlled manner as soon as possible. The first time this is called it will set got_exit_signal to one and store in exit_signal the signal that triggered its execution. */ static RETSIGTYPE exit_signal_handler(int signum) { int old_errno = ERRNO; if(got_exit_signal == 0) { got_exit_signal = 1; exit_signal = signum; } (void)signal(signum, exit_signal_handler); SET_ERRNO(old_errno); } static void install_signal_handlers(void) { #ifdef SIGHUP /* ignore SIGHUP signal */ if((old_sighup_handler = signal(SIGHUP, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGHUP handler: %s", strerror(ERRNO)); #endif #ifdef SIGPIPE /* ignore SIGPIPE signal */ if((old_sigpipe_handler = signal(SIGPIPE, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGPIPE handler: %s", strerror(ERRNO)); #endif #ifdef SIGALRM /* ignore SIGALRM signal */ if((old_sigalrm_handler = signal(SIGALRM, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGALRM handler: %s", strerror(ERRNO)); #endif #ifdef SIGINT /* handle SIGINT signal with our exit_signal_handler */ if((old_sigint_handler = signal(SIGINT, exit_signal_handler)) == SIG_ERR) logmsg("cannot install SIGINT handler: %s", strerror(ERRNO)); else siginterrupt(SIGINT, 1); #endif #ifdef SIGTERM /* handle SIGTERM signal with our exit_signal_handler */ if((old_sigterm_handler = signal(SIGTERM, exit_signal_handler)) == SIG_ERR) logmsg("cannot install SIGTERM handler: %s", strerror(ERRNO)); else siginterrupt(SIGTERM, 1); #endif } static void restore_signal_handlers(void) { #ifdef SIGHUP if(SIG_ERR != old_sighup_handler) (void)signal(SIGHUP, old_sighup_handler); #endif #ifdef SIGPIPE if(SIG_ERR != old_sigpipe_handler) (void)signal(SIGPIPE, old_sigpipe_handler); #endif #ifdef SIGALRM if(SIG_ERR != old_sigalrm_handler) (void)signal(SIGALRM, old_sigalrm_handler); #endif #ifdef SIGINT if(SIG_ERR != old_sigint_handler) (void)signal(SIGINT, old_sigint_handler); #endif #ifdef SIGTERM if(SIG_ERR != old_sigterm_handler) (void)signal(SIGTERM, old_sigterm_handler); #endif } /* * fullread is a wrapper around the read() function. This will repeat the call * to read() until it actually has read the complete number of bytes indicated * in nbytes or it fails with a condition that cannot be handled with a simple * retry of the read call. */ static ssize_t fullread(int filedes, void *buffer, size_t nbytes) { int error; ssize_t rc; ssize_t nread = 0; do { rc = read(filedes, (unsigned char *)buffer + nread, nbytes - nread); if(got_exit_signal) { logmsg("signalled to die"); return -1; } if(rc < 0) { error = ERRNO; if((error == EINTR) || (error == EAGAIN)) continue; logmsg("unrecoverable read() failure: (%d) %s", error, strerror(error)); return -1; } if(rc == 0) { logmsg("got 0 reading from stdin"); return 0; } nread += rc; } while((size_t)nread < nbytes); if(verbose) logmsg("read %zd bytes", nread); return nread; } /* * fullwrite is a wrapper around the write() function. This will repeat the * call to write() until it actually has written the complete number of bytes * indicated in nbytes or it fails with a condition that cannot be handled * with a simple retry of the write call. */ static ssize_t fullwrite(int filedes, const void *buffer, size_t nbytes) { int error; ssize_t wc; ssize_t nwrite = 0; do { wc = write(filedes, (unsigned char *)buffer + nwrite, nbytes - nwrite); if(got_exit_signal) { logmsg("signalled to die"); return -1; } if(wc < 0) { error = ERRNO; if((error == EINTR) || (error == EAGAIN)) continue; logmsg("unrecoverable write() failure: (%d) %s", error, strerror(error)); return -1; } if(wc == 0) { logmsg("put 0 writing to stdout"); return 0; } nwrite += wc; } while((size_t)nwrite < nbytes); if(verbose) logmsg("wrote %zd bytes", nwrite); return nwrite; } /* * read_stdin tries to read from stdin nbytes into the given buffer. This is a * blocking function that will only return TRUE when nbytes have actually been * read or FALSE when an unrecoverable error has been detected. Failure of this * function is an indication that the sockfilt process should terminate. */ static bool read_stdin(void *buffer, size_t nbytes) { ssize_t nread = fullread(fileno(stdin), buffer, nbytes); if(nread != (ssize_t)nbytes) { logmsg("exiting..."); return FALSE; } return TRUE; } /* * write_stdout tries to write to stdio nbytes from the given buffer. This is a * blocking function that will only return TRUE when nbytes have actually been * written or FALSE when an unrecoverable error has been detected. Failure of * this function is an indication that the sockfilt process should terminate. */ static bool write_stdout(const void *buffer, size_t nbytes) { ssize_t nwrite = fullwrite(fileno(stdout), buffer, nbytes); if(nwrite != (ssize_t)nbytes) { logmsg("exiting..."); return FALSE; } return TRUE; } static void lograw(unsigned char *buffer, ssize_t len) { char data[120]; ssize_t i; unsigned char *ptr = buffer; char *optr = data; ssize_t width=0; for(i=0; i60) { logmsg("'%s'", data); width = 0; optr = data; } } if(width) logmsg("'%s'", data); } /* * WinSock select() does not support standard file descriptors, * it can only check SOCKETs. The following function is an attempt * to re-create a select() function with support for other handle types. */ #ifdef USE_WINSOCK /* * select() function with support for WINSOCK2 sockets and all * other handle types supported by WaitForMultipleObjectsEx(). * * TODO: Differentiate between read/write/except for non-SOCKET handles. * * http://msdn.microsoft.com/en-us/library/windows/desktop/ms687028.aspx * http://msdn.microsoft.com/en-us/library/windows/desktop/ms741572.aspx */ static int select_ws(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout) { long networkevents; DWORD milliseconds, wait, idx, avail, events, inputs; WSAEVENT wsaevent, *wsaevents; WSANETWORKEVENTS wsanetevents; INPUT_RECORD *inputrecords; HANDLE handle, *handles; curl_socket_t sock, *fdarr, *wsasocks; int error, fds; DWORD nfd = 0, wsa = 0; int ret = 0; /* check if the input value is valid */ if(nfds < 0) { SET_SOCKERRNO(EINVAL); return -1; } /* check if we got descriptors, sleep in case we got none */ if(!nfds) { Sleep((timeout->tv_sec * 1000) + (timeout->tv_usec / 1000)); return 0; } /* allocate internal array for the original input handles */ fdarr = malloc(nfds * sizeof(curl_socket_t)); if(fdarr == NULL) { SET_SOCKERRNO(ENOMEM); return -1; } /* allocate internal array for the internal event handles */ handles = malloc(nfds * sizeof(HANDLE)); if(handles == NULL) { SET_SOCKERRNO(ENOMEM); return -1; } /* allocate internal array for the internal socket handles */ wsasocks = malloc(nfds * sizeof(curl_socket_t)); if(wsasocks == NULL) { SET_SOCKERRNO(ENOMEM); return -1; } /* allocate internal array for the internal WINSOCK2 events */ wsaevents = malloc(nfds * sizeof(WSAEVENT)); if(wsaevents == NULL) { SET_SOCKERRNO(ENOMEM); return -1; } /* loop over the handles in the input descriptor sets */ for(fds = 0; fds < nfds; fds++) { networkevents = 0; handles[nfd] = 0; if(FD_ISSET(fds, readfds)) networkevents |= FD_READ|FD_ACCEPT|FD_CLOSE; if(FD_ISSET(fds, writefds)) networkevents |= FD_WRITE|FD_CONNECT; if(FD_ISSET(fds, exceptfds)) networkevents |= FD_OOB; /* only wait for events for which we actually care */ if(networkevents) { fdarr[nfd] = (curl_socket_t)fds; if(fds == fileno(stdin)) { handles[nfd] = GetStdHandle(STD_INPUT_HANDLE); } else if(fds == fileno(stdout)) { handles[nfd] = GetStdHandle(STD_OUTPUT_HANDLE); } else if(fds == fileno(stderr)) { handles[nfd] = GetStdHandle(STD_ERROR_HANDLE); } else { wsaevent = WSACreateEvent(); if(wsaevent != WSA_INVALID_EVENT) { error = WSAEventSelect(fds, wsaevent, networkevents); if(error != SOCKET_ERROR) { handles[nfd] = wsaevent; wsasocks[wsa] = (curl_socket_t)fds; wsaevents[wsa] = wsaevent; wsa++; } else { handles[nfd] = (HANDLE)fds; WSACloseEvent(wsaevent); } } } nfd++; } } /* convert struct timeval to milliseconds */ if(timeout) { milliseconds = ((timeout->tv_sec * 1000) + (timeout->tv_usec / 1000)); } else { milliseconds = INFINITE; } /* wait for one of the internal handles to trigger */ wait = WaitForMultipleObjectsEx(nfd, handles, FALSE, milliseconds, FALSE); /* loop over the internal handles returned in the descriptors */ for(idx = 0; idx < nfd; idx++) { fds = fdarr[idx]; handle = handles[idx]; sock = (curl_socket_t)fds; /* check if the current internal handle was triggered */ if(wait != WAIT_FAILED && (wait - WAIT_OBJECT_0) >= idx && WaitForSingleObjectEx(handle, 0, FALSE) == WAIT_OBJECT_0) { /* try to handle the event with STD* handle functions */ if(fds == fileno(stdin)) { /* check if there is no data in the input buffer */ if(!stdin->_cnt) { /* check if we are getting data from a PIPE */ if(!GetConsoleMode(handle, &avail)) { /* check if there is no data from PIPE input */ if(!PeekNamedPipe(handle, NULL, 0, NULL, &avail, NULL)) avail = 0; if(!avail) FD_CLR(sock, readfds); } /* check if there is no data from keyboard input */ else if (!_kbhit()) { /* check if there are INPUT_RECORDs in the input buffer */ if(GetNumberOfConsoleInputEvents(handle, &events)) { if(events > 0) { /* remove INPUT_RECORDs from the input buffer */ inputrecords = (INPUT_RECORD*)malloc(events * sizeof(INPUT_RECORD)); if(inputrecords) { if(!ReadConsoleInput(handle, inputrecords, events, &inputs)) inputs = 0; free(inputrecords); } /* check if we got all inputs, otherwise clear buffer */ if(events != inputs) FlushConsoleInputBuffer(handle); } } /* remove from descriptor set since there is no real data */ FD_CLR(sock, readfds); } } /* stdin is never ready for write or exceptional */ FD_CLR(sock, writefds); FD_CLR(sock, exceptfds); } else if(fds == fileno(stdout) || fds == fileno(stderr)) { /* stdout and stderr are never ready for read or exceptional */ FD_CLR(sock, readfds); FD_CLR(sock, exceptfds); } else { /* try to handle the event with the WINSOCK2 functions */ error = WSAEnumNetworkEvents(fds, NULL, &wsanetevents); if(error != SOCKET_ERROR) { /* remove from descriptor set if not ready for read/accept/close */ if(!(wsanetevents.lNetworkEvents & (FD_READ|FD_ACCEPT|FD_CLOSE))) FD_CLR(sock, readfds); /* remove from descriptor set if not ready for write/connect */ if(!(wsanetevents.lNetworkEvents & (FD_WRITE|FD_CONNECT))) FD_CLR(sock, writefds); /* remove from descriptor set if not exceptional */ if(!(wsanetevents.lNetworkEvents & FD_OOB)) FD_CLR(sock, exceptfds); } } /* check if the event has not been filtered using specific tests */ if(FD_ISSET(sock, readfds) || FD_ISSET(sock, writefds) || FD_ISSET(sock, exceptfds)) { ret++; } } else { /* remove from all descriptor sets since this handle did not trigger */ FD_CLR(sock, readfds); FD_CLR(sock, writefds); FD_CLR(sock, exceptfds); } } for(idx = 0; idx < wsa; idx++) { WSAEventSelect(wsasocks[idx], NULL, 0); WSACloseEvent(wsaevents[idx]); } free(wsaevents); free(wsasocks); free(handles); free(fdarr); return ret; } #define select(a,b,c,d,e) select_ws(a,b,c,d,e) #endif /* sockfdp is a pointer to an established stream or CURL_SOCKET_BAD if sockfd is CURL_SOCKET_BAD, listendfd is a listening socket we must accept() */ static bool juggle(curl_socket_t *sockfdp, curl_socket_t listenfd, enum sockmode *mode) { struct timeval timeout; fd_set fds_read; fd_set fds_write; fd_set fds_err; curl_socket_t sockfd = CURL_SOCKET_BAD; int maxfd = -99; ssize_t rc; ssize_t nread_socket; ssize_t bytes_written; ssize_t buffer_len; int error = 0; /* 'buffer' is this excessively large only to be able to support things like test 1003 which tests exceedingly large server response lines */ unsigned char buffer[17010]; char data[16]; if(got_exit_signal) { logmsg("signalled to die, exiting..."); return FALSE; } #ifdef HAVE_GETPPID /* As a last resort, quit if sockfilt process becomes orphan. Just in case parent ftpserver process has died without killing its sockfilt children */ if(getppid() <= 1) { logmsg("process becomes orphan, exiting"); return FALSE; } #endif timeout.tv_sec = 120; timeout.tv_usec = 0; FD_ZERO(&fds_read); FD_ZERO(&fds_write); FD_ZERO(&fds_err); FD_SET((curl_socket_t)fileno(stdin), &fds_read); switch(*mode) { case PASSIVE_LISTEN: /* server mode */ sockfd = listenfd; /* there's always a socket to wait for */ FD_SET(sockfd, &fds_read); maxfd = (int)sockfd; break; case PASSIVE_CONNECT: sockfd = *sockfdp; if(CURL_SOCKET_BAD == sockfd) { /* eeek, we are supposedly connected and then this cannot be -1 ! */ logmsg("socket is -1! on %s:%d", __FILE__, __LINE__); maxfd = 0; /* stdin */ } else { /* there's always a socket to wait for */ FD_SET(sockfd, &fds_read); maxfd = (int)sockfd; } break; case ACTIVE: sockfd = *sockfdp; /* sockfd turns CURL_SOCKET_BAD when our connection has been closed */ if(CURL_SOCKET_BAD != sockfd) { FD_SET(sockfd, &fds_read); maxfd = (int)sockfd; } else { logmsg("No socket to read on"); maxfd = 0; } break; case ACTIVE_DISCONNECT: logmsg("disconnected, no socket to read on"); maxfd = 0; sockfd = CURL_SOCKET_BAD; break; } /* switch(*mode) */ do { /* select() blocking behavior call on blocking descriptors please */ rc = select(maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout); if(got_exit_signal) { logmsg("signalled to die, exiting..."); return FALSE; } } while((rc == -1) && ((error = SOCKERRNO) == EINTR)); if(rc < 0) { logmsg("select() failed with error: (%d) %s", error, strerror(error)); return FALSE; } if(rc == 0) /* timeout */ return TRUE; if(FD_ISSET(fileno(stdin), &fds_read)) { /* read from stdin, commands/data to be dealt with and possibly passed on to the socket protocol: 4 letter command + LF [mandatory] 4-digit hexadecimal data length + LF [if the command takes data] data [the data being as long as set above] Commands: DATA - plain pass-thru data */ if(!read_stdin(buffer, 5)) return FALSE; logmsg("Received %c%c%c%c (on stdin)", buffer[0], buffer[1], buffer[2], buffer[3] ); if(!memcmp("PING", buffer, 4)) { /* send reply on stdout, just proving we are alive */ if(!write_stdout("PONG\n", 5)) return FALSE; } else if(!memcmp("PORT", buffer, 4)) { /* Question asking us what PORT number we are listening to. Replies to PORT with "IPv[num]/[port]" */ sprintf((char *)buffer, "%s/%hu\n", ipv_inuse, port); buffer_len = (ssize_t)strlen((char *)buffer); snprintf(data, sizeof(data), "PORT\n%04zx\n", buffer_len); if(!write_stdout(data, 10)) return FALSE; if(!write_stdout(buffer, buffer_len)) return FALSE; } else if(!memcmp("QUIT", buffer, 4)) { /* just die */ logmsg("quits"); return FALSE; } else if(!memcmp("DATA", buffer, 4)) { /* data IN => data OUT */ if(!read_stdin(buffer, 5)) return FALSE; buffer[5] = '\0'; buffer_len = (ssize_t)strtol((char *)buffer, NULL, 16); if (buffer_len > (ssize_t)sizeof(buffer)) { logmsg("ERROR: Buffer size (%zu bytes) too small for data size " "(%zd bytes)", sizeof(buffer), buffer_len); return FALSE; } logmsg("> %zd bytes data, server => client", buffer_len); if(!read_stdin(buffer, buffer_len)) return FALSE; lograw(buffer, buffer_len); if(*mode == PASSIVE_LISTEN) { logmsg("*** We are disconnected!"); if(!write_stdout("DISC\n", 5)) return FALSE; } else { /* send away on the socket */ bytes_written = swrite(sockfd, buffer, buffer_len); if(bytes_written != buffer_len) { logmsg("Not all data was sent. Bytes to send: %zd sent: %zd", buffer_len, bytes_written); } } } else if(!memcmp("DISC", buffer, 4)) { /* disconnect! */ if(!write_stdout("DISC\n", 5)) return FALSE; if(sockfd != CURL_SOCKET_BAD) { logmsg("====> Client forcibly disconnected"); sclose(sockfd); *sockfdp = CURL_SOCKET_BAD; if(*mode == PASSIVE_CONNECT) *mode = PASSIVE_LISTEN; else *mode = ACTIVE_DISCONNECT; } else logmsg("attempt to close already dead connection"); return TRUE; } } if((sockfd != CURL_SOCKET_BAD) && (FD_ISSET(sockfd, &fds_read)) ) { if(*mode == PASSIVE_LISTEN) { /* there's no stream set up yet, this is an indication that there's a client connecting. */ listenfd = sockfd; sockfd = accept(listenfd, NULL, NULL); if(CURL_SOCKET_BAD == sockfd) { error = SOCKERRNO; logmsg("accept(%d, NULL, NULL) failed with error: (%d) %s", listenfd, error, strerror(error)); } else { logmsg("====> Client connect"); if(!write_stdout("CNCT\n", 5)) return FALSE; *sockfdp = sockfd; /* store the new socket */ *mode = PASSIVE_CONNECT; /* we have connected */ } return TRUE; } /* read from socket, pass on data to stdout */ nread_socket = sread(sockfd, buffer, sizeof(buffer)); if(nread_socket <= 0) { logmsg("====> Client disconnect"); if(!write_stdout("DISC\n", 5)) return FALSE; sclose(sockfd); *sockfdp = CURL_SOCKET_BAD; if(*mode == PASSIVE_CONNECT) *mode = PASSIVE_LISTEN; else *mode = ACTIVE_DISCONNECT; return TRUE; } snprintf(data, sizeof(data), "DATA\n%04zx\n", nread_socket); if(!write_stdout(data, 10)) return FALSE; if(!write_stdout(buffer, nread_socket)) return FALSE; logmsg("< %zd bytes data, client => server", nread_socket); lograw(buffer, nread_socket); } return TRUE; } static curl_socket_t sockdaemon(curl_socket_t sock, unsigned short *listenport) { /* passive daemon style */ srvr_sockaddr_union_t listener; int flag; int rc; int totdelay = 0; int maxretr = 10; int delay= 20; int attempt = 0; int error = 0; do { attempt++; flag = 1; rc = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&flag, sizeof(flag)); if(rc) { error = SOCKERRNO; logmsg("setsockopt(SO_REUSEADDR) failed with error: (%d) %s", error, strerror(error)); if(maxretr) { rc = wait_ms(delay); if(rc) { /* should not happen */ error = SOCKERRNO; logmsg("wait_ms() failed with error: (%d) %s", error, strerror(error)); sclose(sock); return CURL_SOCKET_BAD; } if(got_exit_signal) { logmsg("signalled to die, exiting..."); sclose(sock); return CURL_SOCKET_BAD; } totdelay += delay; delay *= 2; /* double the sleep for next attempt */ } } } while(rc && maxretr--); if(rc) { logmsg("setsockopt(SO_REUSEADDR) failed %d times in %d ms. Error: (%d) %s", attempt, totdelay, error, strerror(error)); logmsg("Continuing anyway..."); } /* When the specified listener port is zero, it is actually a request to let the system choose a non-zero available port. */ #ifdef ENABLE_IPV6 if(!use_ipv6) { #endif memset(&listener.sa4, 0, sizeof(listener.sa4)); listener.sa4.sin_family = AF_INET; listener.sa4.sin_addr.s_addr = INADDR_ANY; listener.sa4.sin_port = htons(*listenport); rc = bind(sock, &listener.sa, sizeof(listener.sa4)); #ifdef ENABLE_IPV6 } else { memset(&listener.sa6, 0, sizeof(listener.sa6)); listener.sa6.sin6_family = AF_INET6; listener.sa6.sin6_addr = in6addr_any; listener.sa6.sin6_port = htons(*listenport); rc = bind(sock, &listener.sa, sizeof(listener.sa6)); } #endif /* ENABLE_IPV6 */ if(rc) { error = SOCKERRNO; logmsg("Error binding socket on port %hu: (%d) %s", *listenport, error, strerror(error)); sclose(sock); return CURL_SOCKET_BAD; } if(!*listenport) { /* The system was supposed to choose a port number, figure out which port we actually got and update the listener port value with it. */ curl_socklen_t la_size; srvr_sockaddr_union_t localaddr; #ifdef ENABLE_IPV6 if(!use_ipv6) #endif la_size = sizeof(localaddr.sa4); #ifdef ENABLE_IPV6 else la_size = sizeof(localaddr.sa6); #endif memset(&localaddr.sa, 0, (size_t)la_size); if(getsockname(sock, &localaddr.sa, &la_size) < 0) { error = SOCKERRNO; logmsg("getsockname() failed with error: (%d) %s", error, strerror(error)); sclose(sock); return CURL_SOCKET_BAD; } switch (localaddr.sa.sa_family) { case AF_INET: *listenport = ntohs(localaddr.sa4.sin_port); break; #ifdef ENABLE_IPV6 case AF_INET6: *listenport = ntohs(localaddr.sa6.sin6_port); break; #endif default: break; } if(!*listenport) { /* Real failure, listener port shall not be zero beyond this point. */ logmsg("Apparently getsockname() succeeded, with listener port zero."); logmsg("A valid reason for this failure is a binary built without"); logmsg("proper network library linkage. This might not be the only"); logmsg("reason, but double check it before anything else."); sclose(sock); return CURL_SOCKET_BAD; } } /* bindonly option forces no listening */ if(bind_only) { logmsg("instructed to bind port without listening"); return sock; } /* start accepting connections */ rc = listen(sock, 5); if(0 != rc) { error = SOCKERRNO; logmsg("listen(%d, 5) failed with error: (%d) %s", sock, error, strerror(error)); sclose(sock); return CURL_SOCKET_BAD; } return sock; } int main(int argc, char *argv[]) { srvr_sockaddr_union_t me; curl_socket_t sock = CURL_SOCKET_BAD; curl_socket_t msgsock = CURL_SOCKET_BAD; int wrotepidfile = 0; char *pidname= (char *)".sockfilt.pid"; bool juggle_again; int rc; int error; int arg=1; enum sockmode mode = PASSIVE_LISTEN; /* default */ const char *addr = NULL; while(argc>arg) { if(!strcmp("--version", argv[arg])) { printf("sockfilt IPv4%s\n", #ifdef ENABLE_IPV6 "/IPv6" #else "" #endif ); return 0; } else if(!strcmp("--verbose", argv[arg])) { verbose = TRUE; arg++; } else if(!strcmp("--pidfile", argv[arg])) { arg++; if(argc>arg) pidname = argv[arg++]; } else if(!strcmp("--logfile", argv[arg])) { arg++; if(argc>arg) serverlogfile = argv[arg++]; } else if(!strcmp("--ipv6", argv[arg])) { #ifdef ENABLE_IPV6 ipv_inuse = "IPv6"; use_ipv6 = TRUE; #endif arg++; } else if(!strcmp("--ipv4", argv[arg])) { /* for completeness, we support this option as well */ #ifdef ENABLE_IPV6 ipv_inuse = "IPv4"; use_ipv6 = FALSE; #endif arg++; } else if(!strcmp("--bindonly", argv[arg])) { bind_only = TRUE; arg++; } else if(!strcmp("--port", argv[arg])) { arg++; if(argc>arg) { char *endptr; unsigned long ulnum = strtoul(argv[arg], &endptr, 10); if((endptr != argv[arg] + strlen(argv[arg])) || ((ulnum != 0UL) && ((ulnum < 1025UL) || (ulnum > 65535UL)))) { fprintf(stderr, "sockfilt: invalid --port argument (%s)\n", argv[arg]); return 0; } port = curlx_ultous(ulnum); arg++; } } else if(!strcmp("--connect", argv[arg])) { /* Asked to actively connect to the specified local port instead of doing a passive server-style listening. */ arg++; if(argc>arg) { char *endptr; unsigned long ulnum = strtoul(argv[arg], &endptr, 10); if((endptr != argv[arg] + strlen(argv[arg])) || (ulnum < 1025UL) || (ulnum > 65535UL)) { fprintf(stderr, "sockfilt: invalid --connect argument (%s)\n", argv[arg]); return 0; } connectport = curlx_ultous(ulnum); arg++; } } else if(!strcmp("--addr", argv[arg])) { /* Set an IP address to use with --connect; otherwise use localhost */ arg++; if(argc>arg) { addr = argv[arg]; arg++; } } else { puts("Usage: sockfilt [option]\n" " --version\n" " --verbose\n" " --logfile [file]\n" " --pidfile [file]\n" " --ipv4\n" " --ipv6\n" " --bindonly\n" " --port [port]\n" " --connect [port]\n" " --addr [address]"); return 0; } } #ifdef WIN32 win32_init(); atexit(win32_cleanup); setmode(fileno(stdin), O_BINARY); setmode(fileno(stdout), O_BINARY); setmode(fileno(stderr), O_BINARY); #endif install_signal_handlers(); #ifdef ENABLE_IPV6 if(!use_ipv6) #endif sock = socket(AF_INET, SOCK_STREAM, 0); #ifdef ENABLE_IPV6 else sock = socket(AF_INET6, SOCK_STREAM, 0); #endif if(CURL_SOCKET_BAD == sock) { error = SOCKERRNO; logmsg("Error creating socket: (%d) %s", error, strerror(error)); write_stdout("FAIL\n", 5); goto sockfilt_cleanup; } if(connectport) { /* Active mode, we should connect to the given port number */ mode = ACTIVE; #ifdef ENABLE_IPV6 if(!use_ipv6) { #endif memset(&me.sa4, 0, sizeof(me.sa4)); me.sa4.sin_family = AF_INET; me.sa4.sin_port = htons(connectport); me.sa4.sin_addr.s_addr = INADDR_ANY; if (!addr) addr = "127.0.0.1"; Curl_inet_pton(AF_INET, addr, &me.sa4.sin_addr); rc = connect(sock, &me.sa, sizeof(me.sa4)); #ifdef ENABLE_IPV6 } else { memset(&me.sa6, 0, sizeof(me.sa6)); me.sa6.sin6_family = AF_INET6; me.sa6.sin6_port = htons(connectport); if (!addr) addr = "::1"; Curl_inet_pton(AF_INET6, addr, &me.sa6.sin6_addr); rc = connect(sock, &me.sa, sizeof(me.sa6)); } #endif /* ENABLE_IPV6 */ if(rc) { error = SOCKERRNO; logmsg("Error connecting to port %hu: (%d) %s", connectport, error, strerror(error)); write_stdout("FAIL\n", 5); goto sockfilt_cleanup; } logmsg("====> Client connect"); msgsock = sock; /* use this as stream */ } else { /* passive daemon style */ sock = sockdaemon(sock, &port); if(CURL_SOCKET_BAD == sock) { write_stdout("FAIL\n", 5); goto sockfilt_cleanup; } msgsock = CURL_SOCKET_BAD; /* no stream socket yet */ } logmsg("Running %s version", ipv_inuse); if(connectport) logmsg("Connected to port %hu", connectport); else if(bind_only) logmsg("Bound without listening on port %hu", port); else logmsg("Listening on port %hu", port); wrotepidfile = write_pidfile(pidname); if(!wrotepidfile) { write_stdout("FAIL\n", 5); goto sockfilt_cleanup; } do { juggle_again = juggle(&msgsock, sock, &mode); } while(juggle_again); sockfilt_cleanup: if((msgsock != sock) && (msgsock != CURL_SOCKET_BAD)) sclose(msgsock); if(sock != CURL_SOCKET_BAD) sclose(sock); if(wrotepidfile) unlink(pidname); restore_signal_handlers(); if(got_exit_signal) { logmsg("============> sockfilt exits with signal (%d)", exit_signal); /* * To properly set the return status of the process we * must raise the same signal SIGINT or SIGTERM that we * caught and let the old handler take care of it. */ raise(exit_signal); } logmsg("============> sockfilt quits"); return 0; }