comsat.c revision 262435
1/* 2 * Copyright (c) 1980, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30#ifndef lint 31static const char copyright[] = 32"@(#) Copyright (c) 1980, 1993\n\ 33 The Regents of the University of California. All rights reserved.\n"; 34#endif /* not lint */ 35 36#ifndef lint 37#if 0 38static char sccsid[] = "@(#)comsat.c 8.1 (Berkeley) 6/4/93"; 39#endif 40static const char rcsid[] = 41 "$FreeBSD: stable/10/libexec/comsat/comsat.c 262435 2014-02-24 08:21:49Z brueffer $"; 42#endif /* not lint */ 43 44#include <sys/param.h> 45#include <sys/socket.h> 46#include <sys/stat.h> 47#include <sys/file.h> 48#include <sys/wait.h> 49 50#include <netinet/in.h> 51 52#include <ctype.h> 53#include <err.h> 54#include <errno.h> 55#include <netdb.h> 56#include <paths.h> 57#include <pwd.h> 58#include <termios.h> 59#include <signal.h> 60#include <stdio.h> 61#include <stdlib.h> 62#include <string.h> 63#include <syslog.h> 64#include <unistd.h> 65#include <utmpx.h> 66 67static int debug = 0; 68#define dsyslog if (debug) syslog 69 70#define MAXIDLE 120 71 72static char hostname[MAXHOSTNAMELEN]; 73 74static void jkfprintf(FILE *, char[], char[], off_t); 75static void mailfor(char *); 76static void notify(struct utmpx *, char[], off_t, int); 77static void reapchildren(int); 78 79int 80main(int argc __unused, char *argv[] __unused) 81{ 82 struct sockaddr_in from; 83 socklen_t fromlen; 84 int cc; 85 char msgbuf[256]; 86 87 /* verify proper invocation */ 88 fromlen = sizeof(from); 89 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) 90 err(1, "getsockname"); 91 openlog("comsat", LOG_PID, LOG_DAEMON); 92 if (chdir(_PATH_MAILDIR)) { 93 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR); 94 (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 95 exit(1); 96 } 97 (void)gethostname(hostname, sizeof(hostname)); 98 (void)signal(SIGTTOU, SIG_IGN); 99 (void)signal(SIGCHLD, reapchildren); 100 for (;;) { 101 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 102 if (cc <= 0) { 103 if (errno != EINTR) 104 sleep(1); 105 errno = 0; 106 continue; 107 } 108 msgbuf[cc] = '\0'; 109 mailfor(msgbuf); 110 sigsetmask(0L); 111 } 112} 113 114static void 115reapchildren(int signo __unused) 116{ 117 while (wait3(NULL, WNOHANG, NULL) > 0); 118} 119 120static void 121mailfor(char *name) 122{ 123 struct utmpx *utp; 124 char *cp; 125 char *file; 126 off_t offset; 127 int folder; 128 char buf[sizeof(_PATH_MAILDIR) + sizeof(utp->ut_user) + 1]; 129 char buf2[sizeof(_PATH_MAILDIR) + sizeof(utp->ut_user) + 1]; 130 131 if (!(cp = strchr(name, '@'))) 132 return; 133 *cp = '\0'; 134 offset = strtoll(cp + 1, NULL, 10); 135 if (!(cp = strchr(cp + 1, ':'))) 136 file = name; 137 else 138 file = cp + 1; 139 sprintf(buf, "%s/%.*s", _PATH_MAILDIR, (int)sizeof(utp->ut_user), 140 name); 141 if (*file != '/') { 142 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR, 143 (int)sizeof(utp->ut_user), file); 144 file = buf2; 145 } 146 folder = strcmp(buf, file); 147 setutxent(); 148 while ((utp = getutxent()) != NULL) 149 if (utp->ut_type == USER_PROCESS && !strcmp(utp->ut_user, name)) 150 notify(utp, file, offset, folder); 151 endutxent(); 152} 153 154static const char *cr; 155 156static void 157notify(struct utmpx *utp, char file[], off_t offset, int folder) 158{ 159 FILE *tp; 160 struct stat stb; 161 struct termios tio; 162 char tty[20]; 163 const char *s = utp->ut_line; 164 165 if (strncmp(s, "pts/", 4) == 0) 166 s += 4; 167 if (strchr(s, '/')) { 168 /* A slash is an attempt to break security... */ 169 syslog(LOG_AUTH | LOG_NOTICE, "Unexpected `/' in `%s'", 170 utp->ut_line); 171 return; 172 } 173 (void)snprintf(tty, sizeof(tty), "%s%.*s", 174 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line); 175 if (stat(tty, &stb) == -1 || !(stb.st_mode & (S_IXUSR | S_IXGRP))) { 176 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_user, tty); 177 return; 178 } 179 dsyslog(LOG_DEBUG, "notify %s on %s", utp->ut_user, tty); 180 switch (fork()) { 181 case -1: 182 syslog(LOG_NOTICE, "fork failed (%m)"); 183 return; 184 case 0: 185 break; 186 default: 187 return; 188 } 189 if ((tp = fopen(tty, "w")) == NULL) { 190 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno)); 191 _exit(1); 192 } 193 (void)tcgetattr(fileno(tp), &tio); 194 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r"; 195 switch (stb.st_mode & (S_IXUSR | S_IXGRP)) { 196 case S_IXUSR: 197 case (S_IXUSR | S_IXGRP): 198 (void)fprintf(tp, 199 "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s", 200 cr, utp->ut_user, (int)sizeof(hostname), hostname, 201 folder ? cr : "", folder ? "to " : "", folder ? file : "", 202 cr, cr); 203 jkfprintf(tp, utp->ut_user, file, offset); 204 break; 205 case S_IXGRP: 206 (void)fprintf(tp, "\007"); 207 (void)fflush(tp); 208 (void)sleep(1); 209 (void)fprintf(tp, "\007"); 210 break; 211 default: 212 break; 213 } 214 (void)fclose(tp); 215 _exit(0); 216} 217 218static void 219jkfprintf(FILE *tp, char user[], char file[], off_t offset) 220{ 221 unsigned char *cp, ch; 222 FILE *fi; 223 int linecnt, charcnt, inheader; 224 struct passwd *p; 225 unsigned char line[BUFSIZ]; 226 227 /* Set effective uid to user in case mail drop is on nfs */ 228 if ((p = getpwnam(user)) != NULL) 229 (void) setuid(p->pw_uid); 230 231 if ((fi = fopen(file, "r")) == NULL) 232 return; 233 234 (void)fseeko(fi, offset, SEEK_CUR); 235 /* 236 * Print the first 7 lines or 560 characters of the new mail 237 * (whichever comes first). Skip header crap other than 238 * From, Subject, To, and Date. 239 */ 240 linecnt = 7; 241 charcnt = 560; 242 inheader = 1; 243 while (fgets(line, sizeof(line), fi) != NULL) { 244 if (inheader) { 245 if (line[0] == '\n') { 246 inheader = 0; 247 continue; 248 } 249 if (line[0] == ' ' || line[0] == '\t' || 250 (strncmp(line, "From:", 5) && 251 strncmp(line, "Subject:", 8))) 252 continue; 253 } 254 if (linecnt <= 0 || charcnt <= 0) { 255 (void)fprintf(tp, "...more...%s", cr); 256 (void)fclose(fi); 257 return; 258 } 259 /* strip weird stuff so can't trojan horse stupid terminals */ 260 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 261 /* disable upper controls and enable all other 262 8bit codes due to lack of locale knowledge 263 */ 264 if (((ch & 0x80) && ch < 0xA0) || 265 (!(ch & 0x80) && !isprint(ch) && 266 !isspace(ch) && ch != '\a' && ch != '\b') 267 ) { 268 if (ch & 0x80) { 269 ch &= ~0x80; 270 (void)fputs("M-", tp); 271 } 272 if (iscntrl(ch)) { 273 ch ^= 0x40; 274 (void)fputc('^', tp); 275 } 276 } 277 (void)fputc(ch, tp); 278 } 279 (void)fputs(cr, tp); 280 --linecnt; 281 } 282 (void)fprintf(tp, "----%s\n", cr); 283 (void)fclose(fi); 284} 285