From b933ac1e25ec160d86b27d0b6477812fdd01afa4 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Tue, 3 Apr 2007 12:09:46 +0000 Subject: ipsvd: fixes and improvements after testing --- ipsvd/udpsvd.c | 307 --------------------------------------------------------- 1 file changed, 307 deletions(-) delete mode 100644 ipsvd/udpsvd.c (limited to 'ipsvd/udpsvd.c') diff --git a/ipsvd/udpsvd.c b/ipsvd/udpsvd.c deleted file mode 100644 index 700e1aff4..000000000 --- a/ipsvd/udpsvd.c +++ /dev/null @@ -1,307 +0,0 @@ -/* Based on ipsvd utilities written by Gerrit Pape - * which are released into public domain by the author. - * Homepage: http://smarden.sunsite.dk/ipsvd/ - * - * Copyright (C) 2007 Denis Vlasenko. - * - * Licensed under GPLv2, see file LICENSE in this tarball for details. - */ - -/* Based on ipsvd ipsvd-0.12.1. This tcpsvd accepts all options - * which are supported by one from ipsvd-0.12.1, but not all are - * functional. See help text at the end of this file for details. - * - * Code inside #if 0" is parts of original tcpsvd which are not implemented - * for busyboxed version. - * - * Output of verbose mode matches original (modulo bugs and - * unimplemented stuff). Unnatural splitting of IP and PORT - * is retained (personally I prefer one-value "IP:PORT" notation - - * it is a natural string representation of struct sockaddr_XX). - */ - -#include "busybox.h" - -#include "udp_io.c" - -unsigned verbose; - -static void sig_term_handler(int sig) -{ - if (verbose) - printf("%s: info: sigterm received, exit\n", applet_name); - exit(0); -} - -int udpsvd_main(int argc, char **argv); -int udpsvd_main(int argc, char **argv) -{ - const char *instructs; - char *str_t, *user; - unsigned opt; - - char *remote_hostname; - char *local_hostname = NULL; - char *remote_ip; - char *local_ip = local_ip; /* gcc */ - uint16_t local_port, remote_port; - len_and_sockaddr remote; - len_and_sockaddr *localp; - int sock; - int wstat; - unsigned pid; - struct bb_uidgid_t ugid; - - enum { - OPT_v = (1 << 0), - OPT_u = (1 << 1), - OPT_l = (1 << 2), - OPT_h = (1 << 3), - OPT_p = (1 << 4), - OPT_i = (1 << 5), - OPT_x = (1 << 6), - OPT_t = (1 << 7), - }; - - opt_complementary = "-3:ph:vv"; - opt = getopt32(argc, argv, "vu:l:hpi:x:t:", - &user, &local_hostname, &instructs, &instructs, &str_t, &verbose); - //if (opt & OPT_x) iscdb =1; - //if (opt & OPT_t) timeout = xatou(str_t); - if (!(opt & OPT_h)) - remote_hostname = (char *)""; - if (opt & OPT_u) { - if (!get_uidgid(&ugid, user, 1)) - bb_error_msg_and_die("unknown user/group: %s", user); - } - argv += optind; - if (!argv[0][0] || LONE_CHAR(argv[0], '0')) - argv[0] = (char*)"0.0.0.0"; - - /* stdout is used for logging, don't buffer */ - setlinebuf(stdout); - bb_sanitize_stdio(); /* fd# 1,2 must be opened */ - - signal(SIGTERM, sig_term_handler); - signal(SIGPIPE, SIG_IGN); - - local_port = bb_lookup_port(argv[1], "udp", 0); - localp = xhost2sockaddr(argv[0], local_port); - sock = xsocket(localp->sa.sa_family, SOCK_DGRAM, 0); - xmove_fd(sock, 0); /* fd# 0 is the open UDP socket */ - xbind(0, &localp->sa, localp->len); - socket_want_pktinfo(0); - - if (opt & OPT_u) { /* drop permissions */ - xsetgid(ugid.gid); - xsetuid(ugid.uid); - } - - if (verbose) { - /* we do it only for ":port" cosmetics... oh well */ - char *addr = xmalloc_sockaddr2dotted(&localp->sa, localp->len); - printf("%s: info: listening on %s", applet_name, addr); - free(addr); - if (option_mask32 & OPT_u) - printf(", uid %u, gid %u", - (unsigned)ugid.uid, (unsigned)ugid.gid); - puts(", starting"); - } - - again: - /* if (recvfrom(0, NULL, 0, MSG_PEEK, &remote.sa, &localp->len) < 0) { */ - if (recv_from_to(0, NULL, 0, MSG_PEEK, &remote.sa, &localp->sa, localp->len) < 0) { - bb_perror_msg("recvfrom"); - goto again; - } - - while ((pid = fork()) < 0) { - bb_perror_msg("fork failed, sleeping"); - sleep(5); - } - if (pid > 0) { /* parent */ - while (wait_pid(&wstat, pid) == -1) - bb_perror_msg("error waiting for child"); - if (verbose) - printf("%s: info: end %u\n", applet_name, pid); - goto again; - } - - /* Child */ - -#if 0 - /* I'd like to make it so that local addr is fixed to localp->sa, - * but how? The below trick doesn't work... */ - close(0); - set_nport(localp, htons(local_port)); - xmove_fd(xsocket(localp->sa.sa_family, SOCK_DGRAM, 0), 0); - xbind(0, &localp->sa, localp->len); -#endif - - if (verbose) { - local_ip = xmalloc_sockaddr2dotted_noport(&localp->sa, localp->len); - if (!local_hostname) { - local_hostname = xmalloc_sockaddr2host_noport(&localp->sa, localp->len); - if (!local_hostname) - bb_error_msg_and_die("cannot look up local hostname for %s", local_ip); - } - } - - remote_ip = xmalloc_sockaddr2dotted_noport(&remote.sa, localp->len); - remote_port = get_nport(&remote.sa); - remote_port = ntohs(remote_port); - if (verbose) - printf("%s: info: pid %u from %s\n", applet_name, pid, remote_ip); - - if (opt & OPT_h) { - remote_hostname = xmalloc_sockaddr2host(&remote.sa, localp->len); - if (!remote_hostname) { - bb_error_msg("warning: cannot look up hostname for %s", remote_ip); - remote_hostname = (char*)""; - } - } - -#if 0 - if (instructs) { - ac = ipsvd_check(iscdb, &inst, &match, (char*)instructs, - remote_ip, remote_hostname.s, timeout); - if (ac == -1) discard("unable to check inst", remote_ip); - if (ac == IPSVD_ERR) discard("unable to read", (char*)instructs); - } else - ac = IPSVD_DEFAULT; -#endif - - if (verbose) { -#if 0 - out("%s: info: ", applet_name); - switch(ac) { - case IPSVD_DENY: out("deny "); break; - case IPSVD_DEFAULT: case IPSVD_INSTRUCT: out("start "); break; - case IPSVD_EXEC: out("exec "); break; - } -#endif - printf("%s: info: %u %s:%s :%s:%s:%u\n", - applet_name, pid, local_hostname, local_ip, - remote_hostname, remote_ip, remote_port); -#if 0 - if (instructs) { - out(" "); - if (iscdb) { - out((char*)instructs); out("/"); - } - outfix(match.s); - if(inst.s && inst.len && (verbose > 1)) { - out(": "); outinst(&inst); - } - } -#endif - } - -#if 0 - if (ac == IPSVD_DENY) { - recv(0, 0, 0, 0); - _exit(100); - } - if (ac == IPSVD_EXEC) { - args[0] = "/bin/sh"; - args[1] = "-c"; - args[2] = inst.s; - args[3] = NULL; - run = args; - } else run = prog; -#endif - /* Make plain write(1) work for the child by supplying default - * destination address */ - xconnect(0, &remote.sa, localp->len); - dup2(0, 1); - - signal(SIGTERM, SIG_DFL); - signal(SIGPIPE, SIG_DFL); - - argv += 2; - BB_EXECVP(argv[0], argv); - bb_perror_msg_and_die("exec '%s'", argv[0]); -} - -/* -udpsvd [-hpvv] [-u user] [-l name] [-i dir|-x cdb] [-t sec] host port prog - -udpsvd creates an UDP/IP socket, binds it to the address host:port, -and listens on the socket for incoming datagrams. - -If a datagram is available on the socket, udpsvd conditionally starts -a program, with standard input reading from the socket, and standard -output redirected to standard error, to handle this, and possibly -more datagrams. udpsvd does not start the program if another program -that it has started before still is running. If the program exits, -udpsvd again listens to the socket until a new datagram is available. -If there are still datagrams available on the socket, the program -is restarted immediately. - -udpsvd optionally checks for special intructions depending on -the IP address or hostname of the client sending the datagram which -not yet was handled by a running program, see ipsvd-instruct(5) -for details. - -Attention: -UDP is a connectionless protocol. Most programs that handle user datagrams, -such as talkd(8), keep running after receiving a datagram, and process -subsequent datagrams sent to the socket until a timeout is reached. -udpsvd only checks special instructions for a datagram that causes a startup -of the program; not if a program handling datagrams already is running. -It doesn't make much sense to restrict access through special instructions -when using such a program. - -On the other hand, it makes perfectly sense with programs like tftpd(8), -that fork to establish a separate connection to the client when receiving -the datagram. In general it's adequate to set up special instructions for -programs that support being run by tcpwrapper. -Options - -host - host either is a hostname, or a dotted-decimal IP address, or 0. - If host is 0, udpsvd accepts datagrams to any local IP address. -port - udpsvd accepts datagrams to host:port. port may be a name from - /etc/services or a number. -prog - prog consists of one or more arguments. udpsvd normally runs prog - to handle a datagram, and possibly more, that is sent to the socket, - if there is no program that was started before by udpsvd still running - and handling datagrams. --i dir - read instructions for handling new connections from the instructions - directory dir. See ipsvd-instruct(5) for details. --x cdb - read instructions for handling new connections from the constant - database cdb. The constant database normally is created from - an instructions directory by running ipsvd-cdb(8). --t sec - timeout. This option only takes effect if the -i option is given. - While checking the instructions directory, check the time of last - access of the file that matches the clients address or hostname if any, - discard and remove the file if it wasn't accessed within the last - sec seconds; udpsvd does not discard or remove a file if the user's - write permission is not set, for those files the timeout is disabled. - Default is 0, which means that the timeout is disabled. --l name - local hostname. Do not look up the local hostname in DNS, but use name - as hostname. By default udpsvd looks up the local hostname once at startup. --u user[:group] - drop permissions. Switch user ID to user's UID, and group ID to user's - primary GID after creating and binding to the socket. If user - is followed by a colon and a group name, the group ID is switched - to the GID of group instead. All supplementary groups are removed. --h - Look up the client's hostname in DNS. --p - paranoid. After looking up the client's hostname in DNS, look up - the IP addresses in DNS for that hostname, and forget the hostname - if none of the addresses match the client's IP address. You should - set this option if you use hostname based instructions. The -p option - implies the -h option. --v - verbose. Print verbose messages to standard output. --vv - more verbose. Print more verbose messages to standard output. -*/ -- cgit v1.2.3