/* process command to relay udp traffic * */ static int udp_relay( int sockfd, const char* param, size_t plen, const struct in_addr* mifaddr, struct server_ctx* ctx ) { char mcast_addr[ IPADDR_STR_SIZE ]; struct sockaddr_in addr; uint16_t port; pid_t new_pid; int rc = 0, flags; int msockfd = -1, sfilefd = -1, dfilefd = -1, srcfd = -1; char dfile_name[ MAXPATHLEN ]; size_t rcvbuf_len = 0; assert( (sockfd > 0) && param && plen && ctx ); TRACE( (void)tmfprintf( g_flog, "udp_relay : new_socket=[%d] param=[%s]\n", sockfd, param) ); do { rc = parse_udprelay( param, plen, mcast_addr, IPADDR_STR_SIZE, &port ); if( 0 != rc ) { (void) tmfprintf( g_flog, "Error [%d] parsing parameters [%s]\n", rc, param ); break; } if( 1 != inet_aton(mcast_addr, &addr.sin_addr) ) { (void) tmfprintf( g_flog, "Invalid address: [%s]\n", mcast_addr ); rc = ERR_INTERNAL; break; } addr.sin_family = AF_INET; addr.sin_port = htons( (short)port ); } while(0); if( 0 != rc ) { (void) send_http_response( sockfd, 500, "Service error" ); return rc; } /* start the (new) process to relay traffic */ if( 0 != (new_pid = fork()) ) { rc = add_client( ctx, new_pid, mcast_addr, port, sockfd ); return rc; /* parent returns */ } /* child process: */ TRACE( (void)tmfprintf( g_flog, "Client process=[%d] started " "for socket=[%d]\n", getpid(), sockfd) ); (void) get_pidstr( PID_RESET, "c" ); (void)close( ctx->lsockfd ); /* close the reading end of the comm. pipe */ (void)close( ctx->cpipe[0] ); ctx->cpipe[0] = -1; do { /* make write end of pipe non-blocking (we don't want to * block on pipe write while relaying traffic) */ if( -1 == (flags = fcntl( ctx->cpipe[1], F_GETFL )) || -1 == fcntl( ctx->cpipe[1], F_SETFL, flags | O_NONBLOCK ) ) { mperror( g_flog, errno, "%s: fcntl", __func__ ); rc = -1; break; } if( NULL != g_uopt.dstfile ) { (void) snprintf( dfile_name, MAXPATHLEN - 1, "%s.%d", g_uopt.dstfile, getpid() ); dfilefd = creat( dfile_name, S_IRUSR | S_IWUSR | S_IRGRP ); if( -1 == dfilefd ) { mperror( g_flog, errno, "%s: g_uopt.dstfile open", __func__ ); rc = -1; break; } TRACE( (void)tmfprintf( g_flog, "Dest file [%s] opened as fd=[%d]\n", dfile_name, dfilefd ) ); } else dfilefd = -1; if( NULL != g_uopt.srcfile ) { sfilefd = open( g_uopt.srcfile, O_RDONLY | O_NOCTTY ); if( -1 == sfilefd ) { mperror( g_flog, errno, "%s: g_uopt.srcfile open", __func__ ); rc = -1; } else { TRACE( (void) tmfprintf( g_flog, "Source file [%s] opened\n", g_uopt.srcfile ) ); srcfd = sfilefd; } } else { rc = calc_buf_settings( NULL, &rcvbuf_len ); if (0 == rc ) { rc = setup_mcast_listener( &addr, mifaddr, &msockfd, (g_uopt.nosync_sbuf ? 0 : rcvbuf_len) ); srcfd = msockfd; } } if( 0 != rc ) break; rc = relay_traffic( srcfd, sockfd, ctx, dfilefd, mifaddr ); if( 0 != rc ) break; } while(0); if( msockfd > 0 ) { close_mcast_listener( msockfd, mifaddr ); } if( sfilefd > 0 ) { (void) close( sfilefd ); TRACE( (void) tmfprintf( g_flog, "Source file [%s] closed\n", g_uopt.srcfile ) ); } if( dfilefd > 0 ) { (void) close( dfilefd ); TRACE( (void) tmfprintf( g_flog, "Dest file [%s] closed\n", dfile_name ) ); } if( 0 != rc ) { (void) send_http_response( sockfd, 500, "Service error" ); } (void) close( sockfd ); free_server_ctx( ctx ); closelog(); TRACE( (void)tmfprintf( g_flog, "Child process=[%d] exits with rc=[%d]\n", getpid(), rc) ); if( g_flog && (stderr != g_flog) ) { (void) fclose(g_flog); } free_uopt( &g_uopt ); rc = ( 0 != rc ) ? ERR_INTERNAL : rc; exit(rc); /* child exits */ return rc; }
/* process client requests */ int srv_loop( const char* ipaddr, int port, const char* mcast_addr ) { int rc, maxfd, err, nrdy, i; fd_set rset; struct timeval tmout, idle_tmout, *ptmout = NULL; tmfd_t *asock = NULL; size_t n = 0, nasock = 0, max_nasock = LQ_BACKLOG; sigset_t oset, bset; static const long IDLE_TMOUT_SEC = 30; assert( (port > 0) && mcast_addr && ipaddr ); (void)tmfprintf( g_flog, "Server is starting up, max clients = [%u]\n", g_uopt.max_clients ); asock = calloc (max_nasock, sizeof(*asock)); if (!asock) { mperror (g_flog, ENOMEM, "%s: calloc", __func__); return ERR_INTERNAL; } init_server_ctx( &g_srv, g_uopt.max_clients, (ipaddr[0] ? ipaddr : "0.0.0.0") , (uint16_t)port, mcast_addr ); g_srv.rcv_tmout = (u_short)g_uopt.rcv_tmout; g_srv.snd_tmout = RLY_SOCK_TIMEOUT; /* NB: server socket is non-blocking! */ if( 0 != (rc = setup_listener( ipaddr, port, &g_srv.lsockfd, g_uopt.lq_backlog )) ) { return rc; } sigemptyset (&bset); sigaddset (&bset, SIGINT); sigaddset (&bset, SIGQUIT); sigaddset (&bset, SIGCHLD); sigaddset (&bset, SIGTERM); (void) sigprocmask (SIG_BLOCK, &bset, &oset); TRACE( (void)tmfprintf( g_flog, "Entering server loop [%s]\n", SLOOP_TAG) ); while (1) { FD_ZERO( &rset ); FD_SET( g_srv.lsockfd, &rset ); FD_SET( g_srv.cpipe[0], &rset ); maxfd = (g_srv.lsockfd > g_srv.cpipe[0] ) ? g_srv.lsockfd : g_srv.cpipe[0]; for (i = 0; (size_t)i < nasock; ++i) { assert (asock[i].fd >= 0); FD_SET (asock[i].fd, &rset); if (asock[i].fd > maxfd) maxfd = asock[i].fd; } /* if there are accepted sockets - apply specified time-out */ tmout.tv_sec = g_uopt.ssel_tmout; tmout.tv_usec = 0; idle_tmout.tv_sec = IDLE_TMOUT_SEC; idle_tmout.tv_usec = 0; /* enforce *idle* select(2) timeout to alleviate signal contention */ ptmout = ((nasock > 0) && (g_uopt.ssel_tmout > 0)) ? &tmout : &idle_tmout; TRACE( (void)tmfprintf( g_flog, "Waiting for input from [%ld] fd's, " "%s timeout\n", (long)(2 + nasock), (ptmout ? "with" : "NO"))); if (ptmout && ptmout->tv_sec) { TRACE( (void)tmfprintf (g_flog, "select() timeout set to " "[%ld] seconds\n", ptmout->tv_sec) ); } (void) sigprocmask (SIG_UNBLOCK, &bset, NULL); if( must_quit() ) { TRACE( (void)tmfputs( "Must quit now\n", g_flog ) ); rc = 0; break; } nrdy = select (maxfd + 1, &rset, NULL, NULL, ptmout); err = errno; (void) sigprocmask (SIG_BLOCK, &bset, NULL); if( must_quit() ) { TRACE( (void)tmfputs( "Must quit now\n", g_flog ) ); rc = 0; break; } wait_terminated( &g_srv ); if( nrdy < 0 ) { if (EINTR == err) { TRACE( (void)tmfputs ("INTERRUPTED, yet " "will continue.\n", g_flog) ); rc = 0; continue; } mperror( g_flog, err, "%s: select", __func__ ); break; } TRACE( (void)tmfprintf (g_flog, "Got %ld requests\n", (long)nrdy) ); if (0 == nrdy) { /* time-out */ tmout_requests (asock, &nasock); rc = 0; continue; } if( FD_ISSET(g_srv.cpipe[0], &rset) ) { (void) tpstat_read( &g_srv ); if (--nrdy <= 0) continue; } if ((0 < nasock) && (0 < (nrdy - (FD_ISSET(g_srv.lsockfd, &rset) ? 1 : 0)))) { process_requests (asock, &nasock, &rset, &g_srv); /* n now contains # (yet) unprocessed accepted sockets */ } if (FD_ISSET(g_srv.lsockfd, &rset)) { if (nasock >= max_nasock) { (void) tmfprintf (g_flog, "Cannot accept sockets beyond " "the limit [%ld/%ld], skipping\n", (long)nasock, (long)max_nasock); } else { n = max_nasock - nasock; /* append asock */ accept_requests (g_srv.lsockfd, &(asock[nasock]), &n); nasock += n; } } } /* server loop */ TRACE( (void)tmfprintf( g_flog, "Exited server loop [%s]\n", SLOOP_TAG) ); for (i = 0; (size_t)i < nasock; ++i) { if (asock[i].fd > 0) (void) close (asock[i].fd); } free (asock); /* receive additional (blocked signals) */ (void) sigprocmask (SIG_SETMASK, &oset, NULL); wait_terminated( &g_srv ); terminate_all_clients( &g_srv ); wait_all( &g_srv ); if (0 != close( g_srv.lsockfd )) { mperror (g_flog, errno, "server socket close"); } free_server_ctx( &g_srv ); (void)tmfprintf( g_flog, "Server exits with rc=[%d]\n", rc ); return rc; }