/* we expect the form: port */ int xioopen_ipdgram_listen(int argc, const char *argv[], struct opt *opts, int xioflags, xiofile_t *fd, unsigned groups, int pf, int ipproto, int protname) { const char *portname = argv[1]; union sockaddr_union us; union sockaddr_union themunion; union sockaddr_union *them = &themunion; int socktype = SOCK_DGRAM; struct pollfd readfd; bool dofork = false; pid_t pid; char *rangename; char infobuff[256]; unsigned char buff1[1]; socklen_t uslen; socklen_t themlen; int result; if (argc != 2) { Error2("%s: wrong number of parameters (%d instead of 1)", argv[0], argc-1); } if (pf == PF_UNSPEC) { #if WITH_IP4 && WITH_IP6 pf = xioopts.default_ip=='6'?PF_INET6:PF_INET; #elif WITH_IP6 pf = PF_INET6; #else pf = PF_INET; #endif } retropt_socket_pf(opts, &pf); if (applyopts_single(&fd->stream, opts, PH_INIT) < 0) return -1; applyopts(-1, opts, PH_INIT); uslen = socket_init(pf, &us); retropt_bind(opts, pf, socktype, IPPROTO_UDP, (struct sockaddr *)&us, &uslen, 1, fd->stream.para.socket.ip.res_opts[1], fd->stream.para.socket.ip.res_opts[0]); if (false) { ; #if WITH_IP4 } else if (pf == PF_INET) { us.ip4.sin_port = parseport(portname, ipproto); #endif #if WITH_IP6 } else if (pf == PF_INET6) { us.ip6.sin6_port = parseport(portname, ipproto); #endif } else { Error1("xioopen_ipdgram_listen(): unknown address family %d", pf); } retropt_bool(opts, OPT_FORK, &dofork); if (dofork) { if (!(xioflags & XIO_MAYFORK)) { Error("option fork not allowed here"); return STAT_NORETRY; } } #if WITH_IP4 /*|| WITH_IP6*/ if (retropt_string(opts, OPT_RANGE, &rangename) >= 0) { if (xioparserange(rangename, pf, &fd->stream.para.socket.range) < 0) { free(rangename); return STAT_NORETRY; } free(rangename); fd->stream.para.socket.dorange = true; } #endif #if WITH_LIBWRAP xio_retropt_tcpwrap(&fd->stream, opts); #endif /* WITH_LIBWRAP */ if (retropt_ushort(opts, OPT_SOURCEPORT, &fd->stream.para.socket.ip.sourceport) >= 0) { fd->stream.para.socket.ip.dosourceport = true; } retropt_bool(opts, OPT_LOWPORT, &fd->stream.para.socket.ip.lowport); if (dofork) { xiosetchilddied(); /* set SIGCHLD handler */ } while (true) { /* we loop with fork or prohibited packets */ /* now wait for some packet on this datagram socket, get its sender address, connect there, and return */ int one = 1; char infobuff[256]; union sockaddr_union _sockname; union sockaddr_union *la = &_sockname; /* local address */ if ((fd->stream.fd = xiosocket(opts, pf, socktype, ipproto, E_ERROR)) < 0) { return STAT_RETRYLATER; } applyopts(fd->stream.fd, opts, PH_PASTSOCKET); if (Setsockopt(fd->stream.fd, opt_so_reuseaddr.major, opt_so_reuseaddr.minor, &one, sizeof(one)) < 0) { Warn6("setsockopt(%d, %d, %d, {%d}, "F_Zd"): %s", fd->stream.fd, opt_so_reuseaddr.major, opt_so_reuseaddr.minor, one, sizeof(one), strerror(errno)); } applyopts_cloexec(fd->stream.fd, opts); applyopts(fd->stream.fd, opts, PH_PREBIND); applyopts(fd->stream.fd, opts, PH_BIND); if (Bind(fd->stream.fd, &us.soa, uslen) < 0) { Error4("bind(%d, {%s}, "F_Zd"): %s", fd->stream.fd, sockaddr_info(&us.soa, uslen, infobuff, sizeof(infobuff)), uslen, strerror(errno)); return STAT_RETRYLATER; } /* under some circumstances bind() fills sockaddr with interesting info. */ if (Getsockname(fd->stream.fd, &us.soa, &uslen) < 0) { Error4("getsockname(%d, %p, {%d}): %s", fd->stream.fd, &us.soa, uslen, strerror(errno)); } applyopts(fd->stream.fd, opts, PH_PASTBIND); Notice1("listening on UDP %s", sockaddr_info(&us.soa, uslen, infobuff, sizeof(infobuff))); readfd.fd = fd->stream.fd; readfd.events = POLLIN|POLLERR; while (xiopoll(&readfd, 1, NULL) < 0) { if (errno != EINTR) break; } themlen = socket_init(pf, them); do { result = Recvfrom(fd->stream.fd, buff1, 1, MSG_PEEK, &them->soa, &themlen); } while (result < 0 && errno == EINTR); if (result < 0) { Error5("recvfrom(%d, %p, 1, MSG_PEEK, {%s}, {"F_Zu"}): %s", fd->stream.fd, buff1, sockaddr_info(&them->soa, themlen, infobuff, sizeof(infobuff)), themlen, strerror(errno)); return STAT_RETRYLATER; } Notice1("accepting UDP connection from %s", sockaddr_info(&them->soa, themlen, infobuff, sizeof(infobuff))); if (xiocheckpeer(&fd->stream, them, la) < 0) { /* drop packet */ char buff[512]; Recv(fd->stream.fd, buff, sizeof(buff), 0); /* drop packet */ Close(fd->stream.fd); continue; } Info1("permitting UDP connection from %s", sockaddr_info(&them->soa, themlen, infobuff, sizeof(infobuff))); if (dofork) { pid = xio_fork(false, E_ERROR); if (pid < 0) { return STAT_RETRYLATER; } if (pid == 0) { /* child */ break; } /* server: continue loop with socket()+recvfrom() */ /* when we dont close this we get awkward behaviour on Linux 2.4: recvfrom gives 0 bytes with invalid socket address */ if (Close(fd->stream.fd) < 0) { Info2("close(%d): %s", fd->stream.fd, strerror(errno)); } Sleep(1); /*! give child a chance to consume the old packet */ continue; } break; } applyopts(fd->stream.fd, opts, PH_CONNECT); if ((result = Connect(fd->stream.fd, &them->soa, themlen)) < 0) { Error4("connect(%d, {%s}, "F_Zd"): %s", fd->stream.fd, sockaddr_info(&them->soa, themlen, infobuff, sizeof(infobuff)), themlen, strerror(errno)); return STAT_RETRYLATER; } /* set the env vars describing the local and remote sockets */ if (Getsockname(fd->stream.fd, &us.soa, &uslen) < 0) { Warn4("getsockname(%d, %p, {%d}): %s", fd->stream.fd, &us.soa, uslen, strerror(errno)); } xiosetsockaddrenv("SOCK", &us, uslen, IPPROTO_UDP); xiosetsockaddrenv("PEER", them, themlen, IPPROTO_UDP); fd->stream.howtoend = END_SHUTDOWN; applyopts_fchown(fd->stream.fd, opts); applyopts(fd->stream.fd, opts, PH_LATE); if ((result = _xio_openlate(&fd->stream, opts)) < 0) return result; return 0; }
/* creates the listening socket, bind, applies options; waits for incoming connection, checks its source address and port. Depending on fork option, it may fork a subprocess. pf specifies the syntax expected for range option. In the case of generic socket it is 0 (expecting raw binary data), and the real pf can be obtained from us->af_family; for other socket types pf == us->af_family Returns 0 if a connection was accepted; with fork option, this is always in a subprocess! Other return values indicate a problem; this can happen in the master process or in a subprocess. This function does not retry. If you need retries, handle this in a loop in the calling function (and always provide the options...) After fork, we set the forever/retry of the child process to 0 applies and consumes the following option: PH_INIT, PH_PASTSOCKET, PH_PREBIND, PH_BIND, PH_PASTBIND, PH_EARLY, PH_PREOPEN, PH_FD, PH_CONNECTED, PH_LATE, PH_LATE2 OPT_FORK, OPT_SO_TYPE, OPT_SO_PROTOTYPE, OPT_BACKLOG, OPT_RANGE, tcpwrap, OPT_SOURCEPORT, OPT_LOWPORT, cloexec */ int _xioopen_listen(struct single *xfd, int xioflags, struct sockaddr *us, socklen_t uslen, struct opt *opts, int pf, int socktype, int proto, int level) { struct sockaddr sa; socklen_t salen; int backlog = 5; /* why? 1 seems to cause problems under some load */ char *rangename; bool dofork = false; int maxchildren = 0; char infobuff[256]; char lisname[256]; union sockaddr_union _peername; union sockaddr_union _sockname; union sockaddr_union *pa = &_peername; /* peer address */ union sockaddr_union *la = &_sockname; /* local address */ socklen_t pas = sizeof(_peername); /* peer address size */ socklen_t las = sizeof(_sockname); /* local address size */ int result; retropt_bool(opts, OPT_FORK, &dofork); if (dofork) { if (!(xioflags & XIO_MAYFORK)) { Error("option fork not allowed here"); return STAT_NORETRY; } xfd->flags |= XIO_DOESFORK; } retropt_int(opts, OPT_MAX_CHILDREN, &maxchildren); if (! dofork && maxchildren) { Error("option max-children not allowed without option fork"); return STAT_NORETRY; } if (applyopts_single(xfd, opts, PH_INIT) < 0) return -1; if (dofork) { xiosetchilddied(); /* set SIGCHLD handler */ } if ((xfd->fd = xiosocket(opts, us->sa_family, socktype, proto, level)) < 0) { return STAT_RETRYLATER; } applyopts_cloexec(xfd->fd, opts); applyopts(xfd->fd, opts, PH_PREBIND); applyopts(xfd->fd, opts, PH_BIND); if (Bind(xfd->fd, (struct sockaddr *)us, uslen) < 0) { Msg4(level, "bind(%d, {%s}, "F_socklen"): %s", xfd->fd, sockaddr_info(us, uslen, infobuff, sizeof(infobuff)), uslen, strerror(errno)); Close(xfd->fd); return STAT_RETRYLATER; } #if WITH_UNIX if (us->sa_family == AF_UNIX) { applyopts_named(((struct sockaddr_un *)us)->sun_path, opts, PH_FD); } #endif /* under some circumstances (e.g., TCP listen on port 0) bind() fills empty fields that we want to know. */ salen = sizeof(sa); if (Getsockname(xfd->fd, us, &uslen) < 0) { Warn4("getsockname(%d, %p, {%d}): %s", xfd->fd, &us, uslen, strerror(errno)); } applyopts(xfd->fd, opts, PH_PASTBIND); #if WITH_UNIX if (us->sa_family == AF_UNIX) { /*applyopts_early(((struct sockaddr_un *)us)->sun_path, opts);*/ applyopts_named(((struct sockaddr_un *)us)->sun_path, opts, PH_EARLY); applyopts_named(((struct sockaddr_un *)us)->sun_path, opts, PH_PREOPEN); } #endif /* WITH_UNIX */ #if WITH_IP4 /*|| WITH_IP6*/ if (retropt_string(opts, OPT_RANGE, &rangename) >= 0) { if (xioparserange(rangename, pf, &xfd->para.socket.range) < 0) { free(rangename); return STAT_NORETRY; } free(rangename); xfd->para.socket.dorange = true; } #endif #if (WITH_TCP || WITH_UDP) && WITH_LIBWRAP xio_retropt_tcpwrap(xfd, opts); #endif /* && (WITH_TCP || WITH_UDP) && WITH_LIBWRAP */ #if WITH_TCP || WITH_UDP if (retropt_ushort(opts, OPT_SOURCEPORT, &xfd->para.socket.ip.sourceport) >= 0) { xfd->para.socket.ip.dosourceport = true; } retropt_bool(opts, OPT_LOWPORT, &xfd->para.socket.ip.lowport); #endif /* WITH_TCP || WITH_UDP */ applyopts(xfd->fd, opts, PH_PRELISTEN); retropt_int(opts, OPT_BACKLOG, &backlog); if (Listen(xfd->fd, backlog) < 0) { Error3("listen(%d, %d): %s", xfd->fd, backlog, strerror(errno)); return STAT_RETRYLATER; } if (xioopts.logopt == 'm') { Info("starting accept loop, switching to syslog"); diag_set('y', xioopts.syslogfac); xioopts.logopt = 'y'; } else { Info("starting accept loop"); } while (true) { /* but we only loop if fork option is set */ char peername[256]; char sockname[256]; int ps; /* peer socket */ pa = &_peername; la = &_sockname; salen = sizeof(struct sockaddr); do { /*? int level = E_ERROR;*/ Notice1("listening on %s", sockaddr_info(us, uslen, lisname, sizeof(lisname))); ps = Accept(xfd->fd, (struct sockaddr *)&sa, &salen); if (ps >= 0) { /*0 Info4("accept(%d, %p, {"F_Zu"}) -> %d", xfd->fd, &sa, salen, ps);*/ break; /* success, break out of loop */ } if (errno == EINTR) { continue; } if (errno == ECONNABORTED) { Notice4("accept(%d, %p, {"F_socklen"}): %s", xfd->fd, &sa, salen, strerror(errno)); continue; } Msg4(level, "accept(%d, %p, {"F_socklen"}): %s", xfd->fd, &sa, salen, strerror(errno)); Close(xfd->fd); return STAT_RETRYLATER; } while (true); applyopts_cloexec(ps, opts); if (Getpeername(ps, &pa->soa, &pas) < 0) { Warn4("getpeername(%d, %p, {"F_socklen"}): %s", ps, pa, pas, strerror(errno)); pa = NULL; } if (Getsockname(ps, &la->soa, &las) < 0) { Warn4("getsockname(%d, %p, {"F_socklen"}): %s", ps, la, las, strerror(errno)); la = NULL; } Notice2("accepting connection from %s on %s", pa? sockaddr_info(&pa->soa, pas, peername, sizeof(peername)):"NULL", la? sockaddr_info(&la->soa, las, sockname, sizeof(sockname)):"NULL"); if (pa != NULL && la != NULL && xiocheckpeer(xfd, pa, la) < 0) { if (Shutdown(ps, 2) < 0) { Info2("shutdown(%d, 2): %s", ps, strerror(errno)); } Close(ps); continue; } if (pa != NULL) Info1("permitting connection from %s", sockaddr_info((struct sockaddr *)pa, pas, infobuff, sizeof(infobuff))); if (dofork) { pid_t pid; /* mostly int; only used with fork */ sigset_t mask_sigchld; /* we must prevent that the current packet triggers another fork; therefore we wait for a signal from the recent child: USR1 indicates that is has consumed the last packet; CHLD means it has terminated */ /* block SIGCHLD and SIGUSR1 until parent is ready to react */ sigemptyset(&mask_sigchld); sigaddset(&mask_sigchld, SIGCHLD); Sigprocmask(SIG_BLOCK, &mask_sigchld, NULL); if ((pid = xio_fork(false, level==E_ERROR?level:E_WARN)) < 0) { Close(xfd->fd); Sigprocmask(SIG_UNBLOCK, &mask_sigchld, NULL); return STAT_RETRYLATER; } if (pid == 0) { /* child */ pid_t cpid = Getpid(); Sigprocmask(SIG_UNBLOCK, &mask_sigchld, NULL); Info1("just born: child process "F_pid, cpid); xiosetenvulong("PID", cpid, 1); if (Close(xfd->fd) < 0) { Info2("close(%d): %s", xfd->fd, strerror(errno)); } xfd->fd = ps; #if WITH_RETRY /* !? */ xfd->forever = false; xfd->retry = 0; level = E_ERROR; #endif /* WITH_RETRY */ break; } /* server: continue loop with listen */ /* shutdown() closes the socket even for the child process, but close() does what we want */ if (Close(ps) < 0) { Info2("close(%d): %s", ps, strerror(errno)); } /* now we are ready to handle signals */ Sigprocmask(SIG_UNBLOCK, &mask_sigchld, NULL); while (maxchildren) { if (num_child < maxchildren) break; Notice("maxchildren are active, waiting"); /* UINT_MAX would even be nicer, but Openindiana works only with 31 bits */ while (!Sleep(INT_MAX)) ; /* any signal lets us continue */ } Info("still listening"); } else { if (Close(xfd->fd) < 0) { Info2("close(%d): %s", xfd->fd, strerror(errno)); } xfd->fd = ps; break; } } applyopts(xfd->fd, opts, PH_FD); applyopts(xfd->fd, opts, PH_PASTSOCKET); applyopts(xfd->fd, opts, PH_CONNECTED); if ((result = _xio_openlate(xfd, opts)) < 0) return result; /* set the env vars describing the local and remote sockets */ if (la != NULL) xiosetsockaddrenv("SOCK", la, las, proto); if (pa != NULL) xiosetsockaddrenv("PEER", pa, pas, proto); return 0; }