/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2008, 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. * * $Id$ ***************************************************************************/ /* 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! */ #include "setup.h" /* portability help from the lib directory */ #ifdef HAVE_SIGNAL_H #include #endif #ifdef HAVE_UNISTD_H #include #endif #ifdef HAVE_SYS_SOCKET_H #include #endif #ifdef HAVE_NETINET_IN_H #include #endif #ifdef _XOPEN_SOURCE_EXTENDED /* This define is "almost" required to build on HPUX 11 */ #include #endif #ifdef HAVE_NETDB_H #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 memdebug.h last */ #include "memdebug.h" #define DEFAULT_PORT 8999 #ifndef DEFAULT_LOGFILE #define DEFAULT_LOGFILE "log/sockfilt.log" #endif const char *serverlogfile = (char *)DEFAULT_LOGFILE; bool verbose = FALSE; bool use_ipv6 = FALSE; unsigned short port = DEFAULT_PORT; 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); static SIGHANDLER_T old_sighup_handler = SIG_ERR; static SIGHANDLER_T old_sigpipe_handler = SIG_ERR; static SIGHANDLER_T old_sigalrm_handler = SIG_ERR; static SIGHANDLER_T old_sigint_handler = SIG_ERR; static SIGHANDLER_T old_sigterm_handler = SIG_ERR; /* 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: 5s", strerror(ERRNO)); #endif #ifdef SIGPIPE /* ignore SIGPIPE signal */ if((old_sigpipe_handler = signal(SIGPIPE, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGPIPE handler: 5s", strerror(ERRNO)); #endif #ifdef SIGALRM /* ignore SIGALRM signal */ if((old_sigalrm_handler = signal(SIGALRM, SIG_IGN)) == SIG_ERR) logmsg("cannot install SIGALRM handler: 5s", 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: 5s", 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: 5s", 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: %s", 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 %ld bytes", (long)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: %s", 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 %ld bytes", (long)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); } /* 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_t maxfd; ssize_t rc; ssize_t nread_socket; ssize_t bytes_written; ssize_t buffer_len; int error; /* '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(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 = 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 = 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 = 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 { rc = select((int)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, "IPv%d/%d\n", use_ipv6?6:4, (int)port); buffer_len = (ssize_t)strlen((char *)buffer); snprintf(data, sizeof(data), "PORT\n%04x\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 (%ld bytes) too small for data size " "(%ld bytes)", (long)sizeof(buffer), (long)buffer_len); return FALSE; } logmsg("> %d 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: %d sent: %d", 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. */ sockfd = accept(sockfd, NULL, NULL); if(CURL_SOCKET_BAD == sockfd) logmsg("accept() failed"); 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%04x\n", nread_socket); if(!write_stdout(data, 10)) return FALSE; if(!write_stdout(buffer, nread_socket)) return FALSE; logmsg("< %d 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 */ struct sockaddr_in me; #ifdef ENABLE_IPV6 struct sockaddr_in6 me6; #endif /* ENABLE_IPV6 */ int flag = 1; int rc; int totdelay = 0; int maxretr = 10; int delay= 20; int attempt = 0; int error = 0; do { attempt++; rc = setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&flag, sizeof(flag)); if(rc) { error = SOCKERRNO; if(maxretr) { rc = wait_ms(delay); if(rc) { /* should not happen */ error = SOCKERRNO; logmsg("wait_ms() failed: (%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..."); } #ifdef ENABLE_IPV6 if(!use_ipv6) { #endif memset(&me, 0, sizeof(me)); me.sin_family = AF_INET; me.sin_addr.s_addr = INADDR_ANY; me.sin_port = htons(*listenport); rc = bind(sock, (struct sockaddr *) &me, sizeof(me)); #ifdef ENABLE_IPV6 } else { memset(&me6, 0, sizeof(me6)); me6.sin6_family = AF_INET6; me6.sin6_addr = in6addr_any; me6.sin6_port = htons(*listenport); rc = bind(sock, (struct sockaddr *) &me6, sizeof(me6)); } #endif /* ENABLE_IPV6 */ if(rc) { error = SOCKERRNO; logmsg("Error binding socket: (%d) %s", error, strerror(error)); sclose(sock); return CURL_SOCKET_BAD; } if(!*listenport) { /* The system picked a port number, now figure out which port we actually got */ /* we succeeded to bind */ struct sockaddr_in add; socklen_t socksize = sizeof(add); if(getsockname(sock, (struct sockaddr *) &add, &socksize)<0) { error = SOCKERRNO; logmsg("getsockname() failed with error: (%d) %s", error, strerror(error)); sclose(sock); return CURL_SOCKET_BAD; } *listenport = ntohs(add.sin_port); } /* start accepting connections */ rc = listen(sock, 5); if(0 != rc) { error = SOCKERRNO; logmsg("listen() failed with error: (%d) %s", error, strerror(error)); sclose(sock); return CURL_SOCKET_BAD; } return sock; } int main(int argc, char *argv[]) { struct sockaddr_in me; #ifdef ENABLE_IPV6 struct sockaddr_in6 me6; #endif /* ENABLE_IPV6 */ curl_socket_t sock = CURL_SOCKET_BAD; curl_socket_t msgsock = CURL_SOCKET_BAD; int wrotepidfile = 0; char *pidname= (char *)".sockfilt.pid"; 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 use_ipv6=TRUE; #endif arg++; } else if(!strcmp("--ipv4", argv[arg])) { /* for completeness, we support this option as well */ use_ipv6=FALSE; arg++; } else if(!strcmp("--port", argv[arg])) { arg++; if(argc>arg) { port = (unsigned short)atoi(argv[arg]); 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) { connectport = (unsigned short)atoi(argv[arg]); 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" " --port [port]\n" " --connect [port]\n" " --addr [address]"); return 0; } } #ifdef WIN32 win32_init(); atexit(win32_cleanup); #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)); 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, 0, sizeof(me)); me.sin_family = AF_INET; me.sin_port = htons(connectport); me.sin_addr.s_addr = INADDR_ANY; if (!addr) addr = "127.0.0.1"; Curl_inet_pton(AF_INET, addr, &me.sin_addr); rc = connect(sock, (struct sockaddr *) &me, sizeof(me)); #ifdef ENABLE_IPV6 } else { memset(&me6, 0, sizeof(me6)); me6.sin6_family = AF_INET6; me6.sin6_port = htons(connectport); if (!addr) addr = "::1"; Curl_inet_pton(AF_INET6, addr, &me6.sin6_addr); rc = connect(sock, (struct sockaddr *) &me6, sizeof(me6)); } #endif /* ENABLE_IPV6 */ if(rc) { error = SOCKERRNO; logmsg("Error connecting to port %d: (%d) %s", port, error, strerror(error)); 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) goto sockfilt_cleanup; msgsock = CURL_SOCKET_BAD; /* no stream socket yet */ } logmsg("Running IPv%d version", (use_ipv6?6:4)); if(connectport) logmsg("Connected to port %d", connectport); else logmsg("Listening on port %d", port); wrotepidfile = write_pidfile(pidname); if(!wrotepidfile) goto sockfilt_cleanup; while(juggle(&msgsock, sock, &mode)); 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; }