diff options
Diffstat (limited to 'ipsvd/tcpsvd.c')
-rw-r--r-- | ipsvd/tcpsvd.c | 554 |
1 files changed, 0 insertions, 554 deletions
diff --git a/ipsvd/tcpsvd.c b/ipsvd/tcpsvd.c deleted file mode 100644 index 056deff33..000000000 --- a/ipsvd/tcpsvd.c +++ /dev/null @@ -1,554 +0,0 @@ -/* Based on ipsvd utilities written by Gerrit Pape <pape@smarden.org> - * 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 "#ifdef SSLSVD" is for sslsvd and is currently unused. - * 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). - * - * TCPORIGDST{IP,PORT} is busybox-specific addition - */ - -#include <limits.h> -#include <linux/netfilter_ipv4.h> /* wants <limits.h> */ -#include "busybox.h" -#include "ipsvd_perhost.h" - -#ifdef SSLSVD -#include "matrixSsl.h" -#include "ssl_io.h" -#endif - - -static unsigned max_per_host; /* originally in ipsvd_check.c */ -static unsigned cur_per_host; -static unsigned verbose; -static unsigned cnum; -static unsigned cmax = 30; - -/* Must match getopt32 in main! */ -enum { - OPT_c = (1 << 0), - OPT_C = (1 << 1), - OPT_i = (1 << 2), - OPT_x = (1 << 3), - OPT_u = (1 << 4), - OPT_l = (1 << 5), - OPT_E = (1 << 6), - OPT_b = (1 << 7), - OPT_h = (1 << 8), - OPT_p = (1 << 9), - OPT_t = (1 << 10), - OPT_v = (1 << 11), - OPT_V = (1 << 12), - OPT_U = (1 << 13), /* from here: sslsvd only */ - OPT_slash = (1 << 14), - OPT_Z = (1 << 15), - OPT_K = (1 << 16), -}; - -static void connection_status(void) -{ - printf("%s: info: status %u/%u\n", applet_name, cnum, cmax); -} - -static void sig_term_handler(int sig) -{ - if (verbose) - printf("%s: info: sigterm received, exit\n", applet_name); - exit(0); -} - -static void sig_child_handler(int sig) -{ - int wstat; - int pid; - - while ((pid = wait_nohang(&wstat)) > 0) { - if (max_per_host) - ipsvd_perhost_remove(pid); - if (cnum) - cnum--; - if (verbose) { - /* Little bloated, but tries to give accurate info - * how child exited. Makes easier to spot segfaulting - * children etc... */ - unsigned e = 0; - const char *cause = "?exit"; - if (WIFEXITED(wstat)) { - cause++; - e = WEXITSTATUS(wstat); - } else if (WIFSIGNALED(wstat)) { - cause = "signal"; - e = WTERMSIG(wstat); - } - printf("%s: info: end %d %s %d\n", - applet_name, pid, cause, e); - } - } - if (verbose) - connection_status(); -} - -int tcpsvd_main(int argc, char **argv); -int tcpsvd_main(int argc, char **argv) -{ - char *str_c, *str_C, *str_b, *str_t; - char *user; - struct hcc *hccp; - const char *instructs; - char *msg_per_host = NULL; - unsigned len_per_host = len_per_host; /* gcc */ - int need_hostnames, need_remote_ip; - int pid; - int sock; - int conn; - unsigned backlog = 20; - union { - struct sockaddr sa; - struct sockaddr_in sin; - USE_FEATURE_IPV6(struct sockaddr_in6 sin6;) - } sock_adr; - socklen_t sockadr_size; - uint16_t local_port = local_port; - uint16_t remote_port; - char *local_hostname = NULL; - char *remote_hostname = (char*)""; /* "" used if no -h */ - char *local_ip = local_ip; /* gcc */ - char *remote_ip = remote_ip; /* gcc */ - //unsigned iscdb = 0; /* = option_mask32 & OPT_x (TODO) */ - //unsigned long timeout = 0; -#ifndef SSLSVD - struct bb_uidgid_t ugid; -#endif - - /* 3+ args, -i at most once, -p implies -h, -v is counter */ - opt_complementary = "-3:?:i--i:ph:vv"; -#ifdef SSLSVD - getopt32(argc, argv, "c:C:i:x:u:l:Eb:hpt:vU:/:Z:K:", - &str_c, &str_C, &instructs, &instructs, &user, &local_hostname, - &str_b, &str_t, &ssluser, &root, &cert, &key, &verbose - ); -#else - getopt32(argc, argv, "c:C:i:x:u:l:Eb:hpt:v", - &str_c, &str_C, &instructs, &instructs, &user, &local_hostname, - &str_b, &str_t, &verbose - ); -#endif - if (option_mask32 & OPT_c) - cmax = xatou_range(str_c, 1, INT_MAX); - if (option_mask32 & OPT_C) { /* -C n[:message] */ - max_per_host = bb_strtou(str_C, &str_C, 10); - if (str_C[0]) { - if (str_C[0] != ':') - bb_show_usage(); - msg_per_host = str_C + 1; - len_per_host = strlen(msg_per_host); - } - } - if (max_per_host > cmax) - max_per_host = cmax; - if (option_mask32 & OPT_u) { - if (!get_uidgid(&ugid, user, 1)) - bb_error_msg_and_die("unknown user/group: %s", user); - } - if (option_mask32 & OPT_b) - backlog = xatou(str_b); -// if (option_mask32 & OPT_t) timeout = xatou(str_t); -#ifdef SSLSVD - if (option_mask32 & OPT_U) ssluser = (char*)optarg; break; - if (option_mask32 & OPT_slash) root = (char*)optarg; break; - if (option_mask32 & OPT_Z) cert = (char*)optarg; break; - if (option_mask32 & OPT_K) key = (char*)optarg; break; -#endif - 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 */ - - need_hostnames = verbose || !(option_mask32 & OPT_E); - need_remote_ip = max_per_host || need_hostnames; - -#ifdef SSLSVD - sslser = user; - client = 0; - if ((getuid() == 0) && !(option_mask32 & OPT_u)) { - xfunc_exitcode = 100; - bb_error_msg_and_die("fatal: -U ssluser must be set when running as root"); - } - if (option_mask32 & OPT_u) - if (!uidgid_get(&sslugid, ssluser, 1)) { - if (errno) { - xfunc_exitcode = 100; - bb_perror_msg_and_die("fatal: cannot get user/group: %s", ssluser); - } - xfunc_exitcode = 111; - bb_error_msg_and_die("fatal: unknown user/group '%s'", ssluser); - } - if (!cert) cert = "./cert.pem"; - if (!key) key = cert; - if (matrixSslOpen() < 0) - fatal("cannot initialize ssl"); - if (matrixSslReadKeys(&keys, cert, key, 0, ca) < 0) { - if (client) - fatal("cannot read cert, key, or ca file"); - fatal("cannot read cert or key file"); - } - if (matrixSslNewSession(&ssl, keys, 0, SSL_FLAGS_SERVER) < 0) - fatal("cannot create ssl session"); -#endif - - sig_block(SIGCHLD); - signal(SIGCHLD, sig_child_handler); - signal(SIGTERM, sig_term_handler); - signal(SIGPIPE, SIG_IGN); - - if (max_per_host) - ipsvd_perhost_init(cmax); - - local_port = bb_lookup_port(argv[1], "tcp", 0); - sock = create_and_bind_stream_or_die(argv[0], local_port); - xlisten(sock, backlog); - /* ndelay_off(sock); - it is the default I think? */ - -#ifndef SSLSVD - if (option_mask32 & OPT_u) { - /* drop permissions */ - xsetgid(ugid.gid); - xsetuid(ugid.uid); - } -#endif - close(0); - - if (verbose) { - /* we do it only for ":port" cosmetics... oh well */ - len_and_sockaddr *lsa = xhost2sockaddr(argv[0], local_port); - char *addr = xmalloc_sockaddr2dotted(&lsa->sa, lsa->len); - - printf("%s: info: listening on %s", applet_name, addr); - free(addr); -#ifndef SSLSVD - if (option_mask32 & OPT_u) - printf(", uid %u, gid %u", - (unsigned)ugid.uid, (unsigned)ugid.gid); -#endif - puts(", starting"); - } - - /* The rest is a main accept() loop */ - - again: - hccp = NULL; - - while (cnum >= cmax) - sig_pause(); /* wait for any signal (expecting SIGCHLD) */ - - sockadr_size = sizeof(sock_adr); - sig_unblock(SIGCHLD); - conn = accept(sock, &sock_adr.sa, &sockadr_size); - sig_block(SIGCHLD); - if (conn == -1) { - if (errno != EINTR) - bb_perror_msg("accept"); - goto again; - } - - if (max_per_host) { - /* we drop connection immediately if cur_per_host > max_per_host - * (minimizing load under SYN flood) */ - remote_ip = xmalloc_sockaddr2dotted_noport(&sock_adr.sa, sockadr_size); - cur_per_host = ipsvd_perhost_add(remote_ip, max_per_host, &hccp); - if (cur_per_host > max_per_host) { - free(remote_ip); - /* ipsvd_perhost_add detected that max is exceeded - * (and did not store us in connection table) */ - if (msg_per_host) { - ndelay_on(conn); - /* don't test for errors */ - write(conn, msg_per_host, len_per_host); - } - close(conn); - goto again; - } - } - - cnum++; - if (verbose) - connection_status(); - - pid = fork(); - if (pid == -1) { - bb_perror_msg("fork"); - close(conn); - goto again; - } - if (pid != 0) { - /* parent */ - close(conn); - if (hccp) - hccp->pid = pid; - goto again; - } - - /* Child: prepare env, log, and exec prog */ - - close(sock); - - if (!max_per_host && need_remote_ip) - remote_ip = xmalloc_sockaddr2dotted_noport(&sock_adr.sa, sizeof(sock_adr)); - /* else it is already done */ - - remote_port = get_nport(&sock_adr.sa); - remote_port = ntohs(remote_port); - - if (verbose) { - pid = getpid(); - printf("%s: info: pid %d from %s\n", applet_name, pid, remote_ip); - } - - if (need_hostnames && (option_mask32 & OPT_h)) { - remote_hostname = xmalloc_sockaddr2host(&sock_adr.sa, sizeof(sock_adr)); - if (!remote_hostname) { - bb_error_msg("warning: cannot look up hostname for %s", remote_ip); - remote_hostname = (char*)""; - } - } - - sockadr_size = sizeof(sock_adr); - /* Errors ignored (I'm not paranoid enough to imagine kernel - * which doesn't know local ip) */ - getsockname(conn, &sock_adr.sa, &sockadr_size); - - if (need_hostnames) { - local_ip = xmalloc_sockaddr2dotted_noport(&sock_adr.sa, sockadr_size); - local_port = get_nport(&sock_adr.sa); - local_port = ntohs(local_port); - if (!local_hostname) { - local_hostname = xmalloc_sockaddr2host_noport(&sock_adr.sa, sockadr_size); - if (!local_hostname) - bb_error_msg_and_die("cannot look up local hostname for %s", local_ip); - } - } - - if (!(option_mask32 & OPT_E)) { - /* setup ucspi env */ - - /* Extract "original" destination addr:port - * from Linux firewall. Useful when you redirect - * an outbond connection to local handler, and it needs - * to know where it originally tried to connect */ - sockadr_size = sizeof(sock_adr); - if (getsockopt(conn, SOL_IP, SO_ORIGINAL_DST, &sock_adr.sa, &sockadr_size) == 0) { - char *ip = xmalloc_sockaddr2dotted_noport(&sock_adr.sa, sockadr_size); - unsigned port = get_nport(&sock_adr.sa); - port = ntohs(port); - xsetenv("TCPORIGDSTIP", ip); - xsetenv("TCPORIGDSTPORT", utoa(port)); - free(ip); - } - xsetenv("PROTO", "TCP"); - xsetenv("TCPLOCALIP", local_ip); - xsetenv("TCPLOCALPORT", utoa(local_port)); - xsetenv("TCPLOCALHOST", local_hostname); - xsetenv("TCPREMOTEIP", remote_ip); - xsetenv("TCPREMOTEPORT", utoa(remote_port)); - if (option_mask32 & OPT_h) { - xsetenv("TCPREMOTEHOST", remote_hostname); - } - xsetenv("TCPREMOTEINFO", ""); - /* additional */ - if (cur_per_host > 0) - xsetenv("TCPCONCURRENCY", utoa(cur_per_host)); - } - -#if 0 - if (instructs) { - ac = ipsvd_check(iscdb, &inst, &match, (char*)instructs, - remote_ip, remote_hostname, timeout); - if (ac == -1) drop2("cannot check inst", remote_ip); - if (ac == IPSVD_ERR) drop2("cannot read", (char*)instructs); - } else - ac = IPSVD_DEFAULT; -#endif - - if (max_per_host && verbose) - printf("%s: info: concurrency %u %s %u/%u\n", - applet_name, pid, remote_ip, cur_per_host, max_per_host); - - if (verbose) { - printf("%s: info: start %u %s:%s :%s:%s:%u\n", - applet_name, pid, - local_hostname, local_ip, - remote_hostname, remote_ip, (unsigned)remote_port); -#if 0 - switch(ac) { - case IPSVD_DENY: - printf("deny "); break; - case IPSVD_DEFAULT: - case IPSVD_INSTRUCT: - printf("start "); break; - case IPSVD_EXEC: - printf("exec "); break; - } - ... - if (instructs) { - printf(" "); - if (iscdb) { - printf((char*)instructs); - printf("/"); - } - outfix(match.s); - if(inst.s && inst.len && (verbose > 1)) { - printf(": "); - printf(&inst); - } - } - printf("\n"); -#endif - } - -#if 0 - if (ac == IPSVD_DENY) { - close(conn); - _exit(100); - } - if (ac == IPSVD_EXEC) { - args[0] = "/bin/sh"; - args[1] = "-c"; - args[2] = inst.s; - args[3] = 0; - run = args; - } else - run = argv + 2; /* below: we use argv+2 (was using run) */ -#endif - - xmove_fd(conn, 0); - dup2(0, 1); - - signal(SIGTERM, SIG_DFL); - signal(SIGPIPE, SIG_DFL); - signal(SIGCHLD, SIG_DFL); - sig_unblock(SIGCHLD); - - argv += 2; -#ifdef SSLSVD - strcpy(id, utoa(pid); - ssl_io(0, argv); -#else - BB_EXECVP(argv[0], argv); -#endif - bb_perror_msg_and_die("exec '%s'", argv[0]); -} - -/* -tcpsvd [-hpEvv] [-c n] [-C n:msg] [-b n] [-u user] [-l name] - [-i dir|-x cdb] [ -t sec] host port prog - -tcpsvd creates a TCP/IP socket, binds it to the address host:port, -and listens on the socket for incoming connections. - -On each incoming connection, tcpsvd conditionally runs a program, -with standard input reading from the socket, and standard output -writing to the socket, to handle this connection. tcpsvd keeps -listening on the socket for new connections, and can handle -multiple connections simultaneously. - -tcpsvd optionally checks for special instructions depending -on the IP address or hostname of the client that initiated -the connection, see ipsvd-instruct(5). - -host - host either is a hostname, or a dotted-decimal IP address, - or 0. If host is 0, tcpsvd accepts connections to any local - IP address. - * busybox accepts IPv6 addresses and host:port pairs too - In this case second parameter is ignored -port - tcpsvd accepts connections to host:port. port may be a name - from /etc/services or a number. -prog - prog consists of one or more arguments. For each connection, - tcpsvd normally runs prog, with file descriptor 0 reading from - the network, and file descriptor 1 writing to the network. - By default it also sets up TCP-related environment variables, - see tcp-environ(5) --i dir - read instructions for handling new connections from the instructions - directory dir. See ipsvd-instruct(5) for details. - * ignored by busyboxed version --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). - * ignored by busyboxed version --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; - tcpsvd 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. - * ignored by busyboxed version --l name - local hostname. Do not look up the local hostname in DNS, but use name - as hostname. This option must be set if tcpsvd listens on port 53 - to avoid loops. --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. --c n - concurrency. Handle up to n connections simultaneously. Default is 30. - If there are n connections active, tcpsvd defers acceptance of a new - connection until an active connection is closed. --C n[:msg] - per host concurrency. Allow only up to n connections from the same IP - address simultaneously. If there are n active connections from one IP - address, new incoming connections from this IP address are closed - immediately. If n is followed by :msg, the message msg is written - to the client if possible, before closing the connection. By default - msg is empty. See ipsvd-instruct(5) for supported escape sequences in msg. - - For each accepted connection, the current per host concurrency is - available through the environment variable TCPCONCURRENCY. n and msg - can be overwritten by ipsvd(7) instructions, see ipsvd-instruct(5). - By default tcpsvd doesn't keep track of connections. --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 about 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. - * ignored by busyboxed version --b n - backlog. Allow a backlog of approximately n TCP SYNs. On some systems n - is silently limited. Default is 20. --E - no special environment. Do not set up TCP-related environment variables. --v - verbose. Print verbose messsages to standard output. --vv - more verbose. Print more verbose messages to standard output. - * no difference between -v and -vv in busyboxed version -*/ |