Annotation of src/usr.bin/wall/ttymsg.c, Revision 1.17
1.17 ! benno 1: /* $OpenBSD: ttymsg.c,v 1.16 2009/10/27 23:59:49 deraadt Exp $ */
1.1 deraadt 2: /* $NetBSD: ttymsg.c,v 1.3 1994/11/17 07:17:55 jtc Exp $ */
3:
4: /*
5: * Copyright (c) 1989, 1993
6: * The Regents of the University of California. All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions in binary form must reproduce the above copyright
14: * notice, this list of conditions and the following disclaimer in the
15: * documentation and/or other materials provided with the distribution.
1.12 millert 16: * 3. Neither the name of the University nor the names of its contributors
1.1 deraadt 17: * may be used to endorse or promote products derived from this software
18: * without specific prior written permission.
19: *
20: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30: * SUCH DAMAGE.
31: */
32:
33: #include <sys/types.h>
1.17 ! benno 34: #include <sys/stat.h>
1.1 deraadt 35: #include <sys/uio.h>
36: #include <signal.h>
37: #include <fcntl.h>
38: #include <dirent.h>
39: #include <errno.h>
40: #include <paths.h>
41: #include <unistd.h>
42: #include <stdio.h>
43: #include <string.h>
44: #include <stdlib.h>
1.17 ! benno 45: #include <err.h>
1.13 deraadt 46:
47: char *ttymsg(struct iovec *, int, char *, int);
1.1 deraadt 48:
49: /*
1.14 avsm 50: * Display the contents of a uio structure on a terminal. Used by wall(1)
51: * and talkd(8). Forks and finishes in child if write would block,
1.1 deraadt 52: * waiting up to tmout seconds. Returns pointer to error string on unexpected
53: * error; string is not newline-terminated. Various "normal" errors are
54: * ignored (exclusive-use, lack of permission, etc.).
55: */
56: char *
57: ttymsg(iov, iovcnt, line, tmout)
58: struct iovec *iov;
59: int iovcnt;
60: char *line;
61: int tmout;
62: {
63: static char device[MAXNAMLEN] = _PATH_DEV;
64: static char errbuf[1024];
1.9 mpech 65: int cnt, fd, left, wret;
1.1 deraadt 66: struct iovec localiov[6];
67: int forked = 0;
1.5 deraadt 68: struct stat st;
1.7 millert 69: sigset_t mask;
1.1 deraadt 70:
71: if (iovcnt > sizeof(localiov) / sizeof(localiov[0]))
72: return ("too many iov's (change code in wall/ttymsg.c)");
1.3 downsj 73:
74: /*
75: * Ignore lines that start with "ftp" or "uucp".
76: */
1.11 deraadt 77: if ((strncmp(line, "ftp", 3) == 0) ||
78: (strncmp(line, "uucp", 4) == 0))
1.3 downsj 79: return (NULL);
1.1 deraadt 80:
1.11 deraadt 81: (void) strlcpy(device + sizeof(_PATH_DEV) - 1, line,
82: sizeof(device) - (sizeof(_PATH_DEV) - 1));
1.1 deraadt 83: if (strchr(device + sizeof(_PATH_DEV) - 1, '/')) {
84: /* A slash is an attempt to break security... */
85: (void) snprintf(errbuf, sizeof(errbuf), "'/' in \"%s\"",
86: device);
87: return (errbuf);
88: }
1.5 deraadt 89:
1.6 deraadt 90: if (getuid()) {
91: if (stat(device, &st) < 0)
92: return (NULL);
93: if ((st.st_mode & S_IWGRP) == 0)
94: return (NULL);
95: }
1.4 deraadt 96:
1.1 deraadt 97: /*
98: * open will fail on slip lines or exclusive-use lines
99: * if not running as root; not an error.
100: */
101: if ((fd = open(device, O_WRONLY|O_NONBLOCK, 0)) < 0) {
1.6 deraadt 102: if (errno == EBUSY || errno == EACCES)
1.1 deraadt 103: return (NULL);
104: (void) snprintf(errbuf, sizeof(errbuf),
105: "%s: %s", device, strerror(errno));
106: return (errbuf);
107: }
108:
109: for (cnt = left = 0; cnt < iovcnt; ++cnt)
110: left += iov[cnt].iov_len;
111:
112: for (;;) {
113: wret = writev(fd, iov, iovcnt);
114: if (wret >= left)
115: break;
116: if (wret >= 0) {
117: left -= wret;
118: if (iov != localiov) {
119: bcopy(iov, localiov,
120: iovcnt * sizeof(struct iovec));
121: iov = localiov;
122: }
123: for (cnt = 0; wret >= iov->iov_len; ++cnt) {
124: wret -= iov->iov_len;
125: ++iov;
126: --iovcnt;
127: }
128: if (wret) {
1.15 deraadt 129: char *base = iov->iov_base;
130:
131: iov->iov_base = base + wret;
1.1 deraadt 132: iov->iov_len -= wret;
133: }
134: continue;
135: }
136: if (errno == EWOULDBLOCK) {
1.10 deraadt 137: int off = 0;
138: pid_t cpid;
1.1 deraadt 139:
140: if (forked) {
141: (void) close(fd);
142: _exit(1);
143: }
144: cpid = fork();
145: if (cpid < 0) {
146: (void) snprintf(errbuf, sizeof(errbuf),
147: "fork: %s", strerror(errno));
148: (void) close(fd);
149: return (errbuf);
150: }
151: if (cpid) { /* parent */
152: (void) close(fd);
153: return (NULL);
154: }
1.17 ! benno 155:
! 156: if (pledge("stdio", NULL) == -1)
! 157: err(1, "pledge");
! 158:
1.1 deraadt 159: forked++;
160: /* wait at most tmout seconds */
161: (void) signal(SIGALRM, SIG_DFL);
162: (void) signal(SIGTERM, SIG_DFL); /* XXX */
1.7 millert 163: (void) sigemptyset(&mask);
164: (void) sigprocmask(SIG_SETMASK, &mask, NULL);
1.1 deraadt 165: (void) alarm((u_int)tmout);
166: (void) fcntl(fd, O_NONBLOCK, &off);
167: continue;
168: }
169: /*
170: * We get ENODEV on a slip line if we're running as root,
171: * and EIO if the line just went away.
172: */
173: if (errno == ENODEV || errno == EIO)
174: break;
175: (void) close(fd);
176: if (forked)
177: _exit(1);
178: (void) snprintf(errbuf, sizeof(errbuf),
179: "%s: %s", device, strerror(errno));
180: return (errbuf);
181: }
182:
183: (void) close(fd);
184: if (forked)
185: _exit(0);
186: return (NULL);
187: }
![[BACK]](/icons/back.gif){kind=icon}
Return to ttymsg.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / wall