blob: 199e112256f1ef8ae75c700c6463471477a8dfa9 [file] [log] [blame]
Denis Vlasenko7a431b32007-01-14 01:29:06 +00001/* vi: set sw=4 ts=4: */
2/*
3 * Fake identd server.
4 *
Denis Vlasenkod18f52b2008-03-02 12:53:15 +00005 * Copyright (C) 2007 Denys Vlasenko
Denis Vlasenko7a431b32007-01-14 01:29:06 +00006 *
Denys Vlasenko0ef64bd2010-08-16 20:14:46 +02007 * Licensed under GPLv2, see file LICENSE in this source tree.
Denis Vlasenko7a431b32007-01-14 01:29:06 +00008 */
9
Pere Orga5bc8c002011-04-11 03:29:49 +020010//usage:#define fakeidentd_trivial_usage
11//usage: "[-fiw] [-b ADDR] [STRING]"
12//usage:#define fakeidentd_full_usage "\n\n"
13//usage: "Provide fake ident (auth) service\n"
14//usage: "\nOptions:"
15//usage: "\n -f Run in foreground"
16//usage: "\n -i Inetd mode"
17//usage: "\n -w Inetd 'wait' mode"
18//usage: "\n -b ADDR Bind to specified address"
19//usage: "\n STRING Ident answer string (default: nobody)"
20
Denis Vlasenkob6adbf12007-05-26 19:00:18 +000021#include "libbb.h"
Bernhard Reutner-Fischerf4701962008-01-27 12:50:12 +000022#include <syslog.h>
Denis Vlasenko7a431b32007-01-14 01:29:06 +000023#include "isrv.h"
24
25enum { TIMEOUT = 20 };
26
Denis Vlasenko7a431b32007-01-14 01:29:06 +000027typedef struct identd_buf_t {
28 int pos;
29 int fd_flag;
30 char buf[64 - 2*sizeof(int)];
31} identd_buf_t;
32
Denis Vlasenko04c99eb2007-04-07 00:44:31 +000033#define bogouser bb_common_bufsiz1
Denis Vlasenko7a431b32007-01-14 01:29:06 +000034
35static int new_peer(isrv_state_t *state, int fd)
36{
37 int peer;
38 identd_buf_t *buf = xzalloc(sizeof(*buf));
39
Denis Vlasenko7a431b32007-01-14 01:29:06 +000040 peer = isrv_register_peer(state, buf);
41 if (peer < 0)
42 return 0; /* failure */
43 if (isrv_register_fd(state, peer, fd) < 0)
44 return peer; /* failure, unregister peer */
45
Denis Vlasenkod37f2222007-08-19 13:42:08 +000046 buf->fd_flag = fcntl(fd, F_GETFL) | O_NONBLOCK;
Denis Vlasenko7a431b32007-01-14 01:29:06 +000047 isrv_want_rd(state, fd);
48 return 0;
49}
50
51static int do_rd(int fd, void **paramp)
52{
53 identd_buf_t *buf = *paramp;
54 char *cur, *p;
Denis Vlasenkoc14c95e2007-01-14 12:31:26 +000055 int retval = 0; /* session is ok (so far) */
Denis Vlasenko7a431b32007-01-14 01:29:06 +000056 int sz;
57
Denis Vlasenko7a431b32007-01-14 01:29:06 +000058 cur = buf->buf + buf->pos;
59
Denis Vlasenkoc14c95e2007-01-14 12:31:26 +000060 if (buf->fd_flag & O_NONBLOCK)
61 fcntl(fd, F_SETFL, buf->fd_flag);
Denis Vlasenko7a431b32007-01-14 01:29:06 +000062 sz = safe_read(fd, cur, sizeof(buf->buf) - buf->pos);
63
64 if (sz < 0) {
65 if (errno != EAGAIN)
66 goto term; /* terminate this session if !EAGAIN */
67 goto ok;
68 }
69
70 buf->pos += sz;
71 buf->buf[buf->pos] = '\0';
72 p = strpbrk(cur, "\r\n");
73 if (p)
74 *p = '\0';
Denis Vlasenko6b06cb82008-05-15 21:30:45 +000075 if (!p && sz && buf->pos <= (int)sizeof(buf->buf))
Denis Vlasenkoc14c95e2007-01-14 12:31:26 +000076 goto ok;
77 /* Terminate session. If we are in server mode, then
78 * fd is still in nonblocking mode - we never block here */
Denis Vlasenkod97c9242007-01-14 13:12:06 +000079 if (fd == 0) fd++; /* inetd mode? then write to fd 1 */
Denis Vlasenkoc14c95e2007-01-14 12:31:26 +000080 fdprintf(fd, "%s : USERID : UNIX : %s\r\n", buf->buf, bogouser);
Denis Vlasenko7a431b32007-01-14 01:29:06 +000081 term:
Denis Vlasenko7a431b32007-01-14 01:29:06 +000082 free(buf);
Denis Vlasenkoc14c95e2007-01-14 12:31:26 +000083 retval = 1; /* terminate */
84 ok:
85 if (buf->fd_flag & O_NONBLOCK)
86 fcntl(fd, F_SETFL, buf->fd_flag & ~O_NONBLOCK);
87 return retval;
Denis Vlasenko7a431b32007-01-14 01:29:06 +000088}
89
Denis Vlasenkoa60f84e2008-07-05 09:18:54 +000090static int do_timeout(void **paramp UNUSED_PARAM)
Denis Vlasenko7a431b32007-01-14 01:29:06 +000091{
92 return 1; /* terminate session */
93}
94
95static void inetd_mode(void)
96{
97 identd_buf_t *buf = xzalloc(sizeof(*buf));
Denis Vlasenkob8b81a62007-01-14 12:47:27 +000098 /* buf->pos = 0; - xzalloc did it */
Denis Vlasenko7a431b32007-01-14 01:29:06 +000099 /* We do NOT want nonblocking I/O here! */
Denis Vlasenkob8b81a62007-01-14 12:47:27 +0000100 /* buf->fd_flag = 0; - xzalloc did it */
Denis Vlasenko19250812007-01-14 12:07:25 +0000101 do
102 alarm(TIMEOUT);
Denis Vlasenkob8b81a62007-01-14 12:47:27 +0000103 while (do_rd(0, (void*)&buf) == 0);
Denis Vlasenko7a431b32007-01-14 01:29:06 +0000104}
105
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +0000106int fakeidentd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Denis Vlasenkoa60f84e2008-07-05 09:18:54 +0000107int fakeidentd_main(int argc UNUSED_PARAM, char **argv)
Denis Vlasenko7a431b32007-01-14 01:29:06 +0000108{
109 enum {
110 OPT_foreground = 0x1,
111 OPT_inetd = 0x2,
112 OPT_inetdwait = 0x4,
Denis Vlasenkod97c9242007-01-14 13:12:06 +0000113 OPT_fiw = 0x7,
Denis Vlasenko7a431b32007-01-14 01:29:06 +0000114 OPT_bindaddr = 0x8,
115 };
116
117 const char *bind_address = NULL;
118 unsigned opt;
119 int fd;
120
Denis Vlasenkofe7cd642007-08-18 15:32:12 +0000121 opt = getopt32(argv, "fiwb:", &bind_address);
Denis Vlasenko04c99eb2007-04-07 00:44:31 +0000122 strcpy(bogouser, "nobody");
123 if (argv[optind])
124 strncpy(bogouser, argv[optind], sizeof(bogouser));
Denis Vlasenko7a431b32007-01-14 01:29:06 +0000125
Denis Vlasenkod97c9242007-01-14 13:12:06 +0000126 /* Daemonize if no -f and no -i and no -w */
Denis Vlasenko43d5d422008-05-15 19:44:46 +0000127 if (!(opt & OPT_fiw))
Denis Vlasenko5a142022007-03-26 13:20:54 +0000128 bb_daemonize_or_rexec(0, argv);
129
Denis Vlasenkod97c9242007-01-14 13:12:06 +0000130 /* Where to log in inetd modes? "Classic" inetd
131 * probably has its stderr /dev/null'ed (we need log to syslog?),
132 * but daemontools-like utilities usually expect that children
133 * log to stderr. I like daemontools more. Go their way.
134 * (Or maybe we need yet another option "log to syslog") */
135 if (!(opt & OPT_fiw) /* || (opt & OPT_syslog) */) {
Denis Vlasenko5e4fda02009-03-08 23:46:48 +0000136 openlog(applet_name, LOG_PID, LOG_DAEMON);
Denis Vlasenko7a431b32007-01-14 01:29:06 +0000137 logmode = LOGMODE_SYSLOG;
138 }
139
140 if (opt & OPT_inetd) {
141 inetd_mode();
142 return 0;
143 }
144
145 /* Ignore closed connections when writing */
146 signal(SIGPIPE, SIG_IGN);
147
Denis Vlasenkod97c9242007-01-14 13:12:06 +0000148 fd = 0;
149 if (!(opt & OPT_inetdwait)) {
Denis Vlasenko7a431b32007-01-14 01:29:06 +0000150 fd = create_and_bind_stream_or_die(bind_address,
151 bb_lookup_port("identd", "tcp", 113));
152 xlisten(fd, 5);
153 }
154
Denis Vlasenko19250812007-01-14 12:07:25 +0000155 isrv_run(fd, new_peer, do_rd, /*do_wr:*/ NULL, do_timeout,
156 TIMEOUT, (opt & OPT_inetdwait) ? TIMEOUT : 0);
Denis Vlasenko7a431b32007-01-14 01:29:06 +0000157 return 0;
158}