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-rw-r--r--ipsvd/tcpudp.c608
1 files changed, 0 insertions, 608 deletions
diff --git a/ipsvd/tcpudp.c b/ipsvd/tcpudp.c
deleted file mode 100644
index 729b7bc..0000000
--- a/ipsvd/tcpudp.c
+++ /dev/null
@@ -1,608 +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 Denys 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.
- *
- * Busybox version exports TCPLOCALADDR instead of
- * TCPLOCALIP + TCPLOCALPORT pair. ADDR more closely matches reality
- * (which is "struct sockaddr_XXX". Port is not a separate entity,
- * it's just a part of (AF_INET[6]) sockaddr!).
- *
- * TCPORIGDSTADDR is Busybox-specific addition.
- *
- * udp server is hacked up by reusing TCP code. It has the following
- * limitation inherent in Unix DGRAM sockets implementation:
- * - local IP address is retrieved (using recvmsg voodoo) but
- * child's socket is not bound to it (bind cannot be called on
- * already bound socket). Thus it still can emit outgoing packets
- * with wrong source IP...
- * - don't know how to retrieve ORIGDST for udp.
- */
-
-#include <limits.h>
-#include <linux/netfilter_ipv4.h> /* wants <limits.h> */
-
-#include "libbb.h"
-#include "ipsvd_perhost.h"
-
-#ifdef SSLSVD
-#include "matrixSsl.h"
-#include "ssl_io.h"
-#endif
-
-struct globals {
- unsigned verbose;
- unsigned max_per_host;
- unsigned cur_per_host;
- unsigned cnum;
- unsigned cmax;
- char **env_cur;
- char *env_var[1]; /* actually bigger */
-};
-#define G (*(struct globals*)&bb_common_bufsiz1)
-#define verbose (G.verbose )
-#define max_per_host (G.max_per_host)
-#define cur_per_host (G.cur_per_host)
-#define cnum (G.cnum )
-#define cmax (G.cmax )
-#define env_cur (G.env_cur )
-#define env_var (G.env_var )
-#define INIT_G() \
- do { \
- cmax = 30; \
- env_cur = &env_var[0]; \
- } while (0)
-
-
-/* We have to be careful about leaking memory in repeated setenv's */
-static void xsetenv_plain(const char *n, const char *v)
-{
- char *var = xasprintf("%s=%s", n, v);
- *env_cur++ = var;
- putenv(var);
-}
-
-static void xsetenv_proto(const char *proto, const char *n, const char *v)
-{
- char *var = xasprintf("%s%s=%s", proto, n, v);
- *env_cur++ = var;
- putenv(var);
-}
-
-static void undo_xsetenv(void)
-{
- char **pp = env_cur = &env_var[0];
- while (*pp) {
- char *var = *pp;
- *strchrnul(var, '=') = '\0';
- unsetenv(var);
- free(var);
- *pp++ = NULL;
- }
-}
-
-static void sig_term_handler(int sig)
-{
- if (verbose)
- bb_error_msg("got signal %u, exit", sig);
- kill_myself_with_sig(sig);
-}
-
-/* Little bloated, but tries to give accurate info how child exited.
- * Makes easier to spot segfaulting children etc... */
-static void print_waitstat(unsigned pid, int wstat)
-{
- unsigned e = 0;
- const char *cause = "?exit";
-
- if (WIFEXITED(wstat)) {
- cause++;
- e = WEXITSTATUS(wstat);
- } else if (WIFSIGNALED(wstat)) {
- cause = "signal";
- e = WTERMSIG(wstat);
- }
- bb_error_msg("end %d %s %d", pid, cause, e);
-}
-
-/* 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)
-{
- /* "only 1 client max" desn't need this */
- if (cmax > 1)
- bb_error_msg("status %u/%u", cnum, cmax);
-}
-
-static void sig_child_handler(int sig ATTRIBUTE_UNUSED)
-{
- int wstat;
- int pid;
-
- while ((pid = wait_any_nohang(&wstat)) > 0) {
- if (max_per_host)
- ipsvd_perhost_remove(pid);
- if (cnum)
- cnum--;
- if (verbose)
- print_waitstat(pid, wstat);
- }
- if (verbose)
- connection_status();
-}
-
-int tcpudpsvd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int tcpudpsvd_main(int argc ATTRIBUTE_UNUSED, char **argv)
-{
- char *str_C, *str_t;
- char *user;
- struct hcc *hccp;
- const char *instructs;
- char *msg_per_host = NULL;
- unsigned len_per_host = len_per_host; /* gcc */
-#ifndef SSLSVD
- struct bb_uidgid_t ugid;
-#endif
- bool tcp;
- uint16_t local_port;
- char *preset_local_hostname = NULL;
- char *remote_hostname = remote_hostname; /* for compiler */
- char *remote_addr = remote_addr; /* for compiler */
- len_and_sockaddr *lsa;
- len_and_sockaddr local, remote;
- socklen_t sa_len;
- int pid;
- int sock;
- int conn;
- unsigned backlog = 20;
-
- INIT_G();
-
- tcp = (applet_name[0] == 't');
-
- /* 3+ args, -i at most once, -p implies -h, -v is counter, -b N, -c N */
- opt_complementary = "-3:i--i:ph:vv:b+:c+";
-#ifdef SSLSVD
- getopt32(argv, "+c:C:i:x:u:l:Eb:hpt:vU:/:Z:K:",
- &cmax, &str_C, &instructs, &instructs, &user, &preset_local_hostname,
- &backlog, &str_t, &ssluser, &root, &cert, &key, &verbose
- );
-#else
- /* "+": stop on first non-option */
- getopt32(argv, "+c:C:i:x:u:l:Eb:hpt:v",
- &cmax, &str_C, &instructs, &instructs, &user, &preset_local_hostname,
- &backlog, &str_t, &verbose
- );
-#endif
- 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);
- }
-#ifdef SSLSVD
- if (option_mask32 & OPT_U) ssluser = optarg;
- if (option_mask32 & OPT_slash) root = optarg;
- if (option_mask32 & OPT_Z) cert = optarg;
- if (option_mask32 & OPT_K) key = optarg;
-#endif
- argv += optind;
- if (!argv[0][0] || LONE_CHAR(argv[0], '0'))
- argv[0] = (char*)"0.0.0.0";
-
- /* Per-IP flood protection is not thought-out for UDP */
- if (!tcp)
- max_per_host = 0;
-
- bb_sanitize_stdio(); /* fd# 0,1,2 must be opened */
-
-#ifdef SSLSVD
- sslser = user;
- client = 0;
- if ((getuid() == 0) && !(option_mask32 & OPT_u)) {
- xfunc_exitcode = 100;
- bb_error_msg_and_die("-U ssluser must be set when running as root");
- }
- if (option_mask32 & OPT_u)
- if (!uidgid_get(&sslugid, ssluser, 1)) {
- if (errno) {
- bb_perror_msg_and_die("fatal: cannot get user/group: %s", ssluser);
- }
- bb_error_msg_and_die("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);
- bb_signals(BB_SIGS_FATAL, sig_term_handler);
- signal(SIGPIPE, SIG_IGN);
-
- if (max_per_host)
- ipsvd_perhost_init(cmax);
-
- local_port = bb_lookup_port(argv[1], tcp ? "tcp" : "udp", 0);
- lsa = xhost2sockaddr(argv[0], local_port);
- argv += 2;
-
- sock = xsocket(lsa->u.sa.sa_family, tcp ? SOCK_STREAM : SOCK_DGRAM, 0);
- setsockopt_reuseaddr(sock);
- sa_len = lsa->len; /* I presume sockaddr len stays the same */
- xbind(sock, &lsa->u.sa, sa_len);
- if (tcp)
- xlisten(sock, backlog);
- else /* udp: needed for recv_from_to to work: */
- socket_want_pktinfo(sock);
- /* 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
-
- if (verbose) {
- char *addr = xmalloc_sockaddr2dotted(&lsa->u.sa);
- bb_error_msg("listening on %s, starting", addr);
- free(addr);
-#ifndef SSLSVD
- if (option_mask32 & OPT_u)
- printf(", uid %u, gid %u",
- (unsigned)ugid.uid, (unsigned)ugid.gid);
-#endif
- }
-
- /* Main accept() loop */
-
- again:
- hccp = NULL;
-
- while (cnum >= cmax)
- wait_for_any_sig(); /* expecting SIGCHLD */
-
- /* Accept a connection to fd #0 */
- again1:
- close(0);
- again2:
- sig_unblock(SIGCHLD);
- local.len = remote.len = sa_len;
- if (tcp) {
- conn = accept(sock, &remote.u.sa, &remote.len);
- } else {
- /* In case recv_from_to won't be able to recover local addr.
- * Also sets port - recv_from_to is unable to do it. */
- local = *lsa;
- conn = recv_from_to(sock, NULL, 0, MSG_PEEK,
- &remote.u.sa, &local.u.sa, sa_len);
- }
- sig_block(SIGCHLD);
- if (conn < 0) {
- if (errno != EINTR)
- bb_perror_msg(tcp ? "accept" : "recv");
- goto again2;
- }
- xmove_fd(tcp ? conn : sock, 0);
-
- if (max_per_host) {
- /* Drop connection immediately if cur_per_host > max_per_host
- * (minimizing load under SYN flood) */
- remote_addr = xmalloc_sockaddr2dotted_noport(&remote.u.sa);
- cur_per_host = ipsvd_perhost_add(remote_addr, max_per_host, &hccp);
- if (cur_per_host > max_per_host) {
- /* ipsvd_perhost_add detected that max is exceeded
- * (and did not store ip in connection table) */
- free(remote_addr);
- if (msg_per_host) {
- /* don't block or test for errors */
- send(0, msg_per_host, len_per_host, MSG_DONTWAIT);
- }
- goto again1;
- }
- /* NB: remote_addr is not leaked, it is stored in conn table */
- }
-
- if (!tcp) {
- /* Voodoo magic: making udp sockets each receive its own
- * packets is not trivial, and I still not sure
- * I do it 100% right.
- * 1) we have to do it before fork()
- * 2) order is important - is it right now? */
-
- /* Open new non-connected UDP socket for further clients... */
- sock = xsocket(lsa->u.sa.sa_family, SOCK_DGRAM, 0);
- setsockopt_reuseaddr(sock);
- /* Make plain write/send work for old socket by supplying default
- * destination address. This also restricts incoming packets
- * to ones coming from this remote IP. */
- xconnect(0, &remote.u.sa, sa_len);
- /* hole? at this point we have no wildcard udp socket...
- * can this cause clients to get "port unreachable" icmp?
- * Yup, time window is very small, but it exists (is it?) */
- /* ..."open new socket", continued */
- xbind(sock, &lsa->u.sa, sa_len);
- socket_want_pktinfo(sock);
-
- /* Doesn't work:
- * we cannot replace fd #0 - we will lose pending packet
- * which is already buffered for us! And we cannot use fd #1
- * instead - it will "intercept" all following packets, but child
- * does not expect data coming *from fd #1*! */
-#if 0
- /* Make it so that local addr is fixed to localp->u.sa
- * and we don't accidentally accept packets to other local IPs. */
- /* NB: we possibly bind to the _very_ same_ address & port as the one
- * already bound in parent! This seems to work in Linux.
- * (otherwise we can move socket to fd #0 only if bind succeeds) */
- close(0);
- set_nport(localp, htons(local_port));
- xmove_fd(xsocket(localp->u.sa.sa_family, SOCK_DGRAM, 0), 0);
- setsockopt_reuseaddr(0); /* crucial */
- xbind(0, &localp->u.sa, localp->len);
-#endif
- }
-
- pid = vfork();
- if (pid == -1) {
- bb_perror_msg("vfork");
- goto again;
- }
-
- if (pid != 0) {
- /* Parent */
- cnum++;
- if (verbose)
- connection_status();
- if (hccp)
- hccp->pid = pid;
- /* clean up changes done by vforked child */
- undo_xsetenv();
- goto again;
- }
-
- /* Child: prepare env, log, and exec prog */
-
- /* Closing tcp listening socket */
- if (tcp)
- close(sock);
-
- { /* vfork alert! every xmalloc in this block should be freed! */
- char *local_hostname = local_hostname; /* for compiler */
- char *local_addr = NULL;
- char *free_me0 = NULL;
- char *free_me1 = NULL;
- char *free_me2 = NULL;
-
- if (verbose || !(option_mask32 & OPT_E)) {
- if (!max_per_host) /* remote_addr is not yet known */
- free_me0 = remote_addr = xmalloc_sockaddr2dotted(&remote.u.sa);
- if (option_mask32 & OPT_h) {
- free_me1 = remote_hostname = xmalloc_sockaddr2host_noport(&remote.u.sa);
- if (!remote_hostname) {
- bb_error_msg("cannot look up hostname for %s", remote_addr);
- remote_hostname = remote_addr;
- }
- }
- /* Find out local IP peer connected to.
- * Errors ignored (I'm not paranoid enough to imagine kernel
- * which doesn't know local IP). */
- if (tcp)
- getsockname(0, &local.u.sa, &local.len);
- /* else: for UDP it is done earlier by parent */
- local_addr = xmalloc_sockaddr2dotted(&local.u.sa);
- if (option_mask32 & OPT_h) {
- local_hostname = preset_local_hostname;
- if (!local_hostname) {
- free_me2 = local_hostname = xmalloc_sockaddr2host_noport(&local.u.sa);
- if (!local_hostname)
- bb_error_msg_and_die("cannot look up hostname for %s", local_addr);
- }
- /* else: local_hostname is not NULL, but is NOT malloced! */
- }
- }
- if (verbose) {
- pid = getpid();
- if (max_per_host) {
- bb_error_msg("concurrency %s %u/%u",
- remote_addr,
- cur_per_host, max_per_host);
- }
- bb_error_msg((option_mask32 & OPT_h)
- ? "start %u %s-%s (%s-%s)"
- : "start %u %s-%s",
- pid,
- local_addr, remote_addr,
- local_hostname, remote_hostname);
- }
-
- if (!(option_mask32 & OPT_E)) {
- /* setup ucspi env */
- const char *proto = tcp ? "TCP" : "UDP";
-
- /* 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 */
- if (tcp && getsockopt(0, SOL_IP, SO_ORIGINAL_DST, &local.u.sa, &local.len) == 0) {
- char *addr = xmalloc_sockaddr2dotted(&local.u.sa);
- xsetenv_plain("TCPORIGDSTADDR", addr);
- free(addr);
- }
- xsetenv_plain("PROTO", proto);
- xsetenv_proto(proto, "LOCALADDR", local_addr);
- xsetenv_proto(proto, "REMOTEADDR", remote_addr);
- if (option_mask32 & OPT_h) {
- xsetenv_proto(proto, "LOCALHOST", local_hostname);
- xsetenv_proto(proto, "REMOTEHOST", remote_hostname);
- }
- //compat? xsetenv_proto(proto, "REMOTEINFO", "");
- /* additional */
- if (cur_per_host > 0) /* can not be true for udp */
- xsetenv_plain("TCPCONCURRENCY", utoa(cur_per_host));
- }
- free(local_addr);
- free(free_me0);
- free(free_me1);
- free(free_me2);
- }
-
- xdup2(0, 1);
-
- signal(SIGTERM, SIG_DFL);
- signal(SIGPIPE, SIG_DFL);
- signal(SIGCHLD, SIG_DFL);
- sig_unblock(SIGCHLD);
-
-#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
-*/
generated by cgit v1.1 at 2024-12-25 16:49:58 +0000