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/* 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 #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"
unsigned verbose;
static void sig_term_handler(int sig)
{
if (verbose)
printf("udpsvd: info: sigterm received, exit\n");
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;
// unsigned lookuphost = 0;
// unsigned paranoid = 0;
// unsigned long timeout = 0;
char *remote_hostname;
char *local_hostname = local_hostname; /* gcc */
char *remote_ip;
char *local_ip = local_ip; /* gcc */
uint16_t local_port, remote_port;
union {
struct sockaddr sa;
struct sockaddr_in sin;
USE_FEATURE_IPV6(struct sockaddr_in6 sin6;)
} sock_adr;
socklen_t sockadr_size;
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 = "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";
setlinebuf(stdout);
signal(SIGTERM, sig_term_handler);
signal(SIGPIPE, SIG_IGN);
local_port = bb_lookup_port(argv[1], "udp", 0);
sock = create_and_bind_dgram_or_die(argv[0], local_port);
if (opt & OPT_u) { /* drop permissions */
xsetgid(ugid.gid);
xsetuid(ugid.uid);
}
bb_sanitize_stdio(); /* fd# 1,2 must be opened */
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("udpsvd: info: listening on %s", addr);
free(addr);
if (option_mask32 & OPT_u)
printf(", uid %u, gid %u",
(unsigned)ugid.uid, (unsigned)ugid.gid);
puts(", starting");
}
again:
/* io[0].fd = s;
io[0].events = IOPAUSE_READ;
io[0].revents = 0;
taia_now(&now);
taia_uint(&deadline, 3600);
taia_add(&deadline, &now, &deadline);
iopause(io, 1, &deadline, &now);
if (!(io[0].revents | IOPAUSE_READ))
goto again;
io[0].revents = 0;
*/
sockadr_size = sizeof(sock_adr);
if (recvfrom(sock, NULL, 0, MSG_PEEK, &sock_adr.sa, &sockadr_size) == -1) {
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("udpsvd: info: end %u\n", pid);
goto again;
}
/* Child */
/* if (recvfrom(sock, 0, 0, MSG_PEEK, (struct sockaddr *)&sock_adr, &sockadr_size) == -1)
drop("unable to read from socket");
*/
if (verbose) {
local_ip = argv[0]; // TODO: recv_from_to!
local_hostname = (char*)"localhost";
}
remote_ip = xmalloc_sockaddr2dotted_noport(&sock_adr.sa, sockadr_size);
remote_port = get_nport(&sock_adr.sa);
remote_port = ntohs(remote_port);
if (verbose) {
printf("udpsvd: info: pid %u from %s\n", pid, remote_ip);
}
if (opt & 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*)"";
}
}
#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("udpsvd: info: ");
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("udpsvd: info: %u %s:%s :%s:%s:%u\n",
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(s, 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
xmove_fd(sock, 0);
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]);
}
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