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. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 static const char copyright[] = 36 "@(#) Copyright (c) 1980, 1993\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38 #endif /* not lint */ 39 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)comsat.c 8.1 (Berkeley) 6/4/93"; 43 #endif 44 static const char rcsid[] = 45 "$FreeBSD: src/libexec/comsat/comsat.c,v 1.13.2.1 2002/08/09 02:56:30 johan Exp $"; 46 #endif /* not lint */ 47 48 #include <sys/param.h> 49 #include <sys/socket.h> 50 #include <sys/stat.h> 51 #include <sys/file.h> 52 #include <sys/wait.h> 53 54 #include <netinet/in.h> 55 56 #include <ctype.h> 57 #include <err.h> 58 #include <errno.h> 59 #include <netdb.h> 60 #include <paths.h> 61 #include <pwd.h> 62 #include <termios.h> 63 #include <signal.h> 64 #include <stdio.h> 65 #include <stdlib.h> 66 #include <string.h> 67 #include <syslog.h> 68 #include <unistd.h> 69 #include <utmp.h> 70 71 int debug = 0; 72 #define dsyslog if (debug) syslog 73 74 #define MAXIDLE 120 75 76 char hostname[MAXHOSTNAMELEN]; 77 struct utmp *utmp = NULL; 78 time_t lastmsgtime; 79 int nutmp, uf; 80 81 void jkfprintf __P((FILE *, char[], char[], off_t)); 82 void mailfor __P((char *)); 83 void notify __P((struct utmp *, char[], off_t, int)); 84 void onalrm __P((int)); 85 void reapchildren __P((int)); 86 87 int 88 main(argc, argv) 89 int argc; 90 char *argv[]; 91 { 92 struct sockaddr_in from; 93 register int cc; 94 int fromlen; 95 char msgbuf[256]; 96 97 /* verify proper invocation */ 98 fromlen = sizeof(from); 99 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) 100 err(1, "getsockname"); 101 openlog("comsat", LOG_PID, LOG_DAEMON); 102 if (chdir(_PATH_MAILDIR)) { 103 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR); 104 (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 105 exit(1); 106 } 107 if ((uf = open(_PATH_UTMP, O_RDONLY, 0)) < 0) { 108 syslog(LOG_ERR, "open: %s: %m", _PATH_UTMP); 109 (void) recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 110 exit(1); 111 } 112 (void)time(&lastmsgtime); 113 (void)gethostname(hostname, sizeof(hostname)); 114 onalrm(0); 115 (void)signal(SIGALRM, onalrm); 116 (void)signal(SIGTTOU, SIG_IGN); 117 (void)signal(SIGCHLD, reapchildren); 118 for (;;) { 119 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 120 if (cc <= 0) { 121 if (errno != EINTR) 122 sleep(1); 123 errno = 0; 124 continue; 125 } 126 if (!nutmp) /* no one has logged in yet */ 127 continue; 128 sigblock(sigmask(SIGALRM)); 129 msgbuf[cc] = '\0'; 130 (void)time(&lastmsgtime); 131 mailfor(msgbuf); 132 sigsetmask(0L); 133 } 134 } 135 136 void 137 reapchildren(signo) 138 int signo; 139 { 140 while (wait3(NULL, WNOHANG, NULL) > 0); 141 } 142 143 void 144 onalrm(signo) 145 int signo; 146 { 147 static u_int utmpsize; /* last malloced size for utmp */ 148 static u_int utmpmtime; /* last modification time for utmp */ 149 struct stat statbf; 150 151 if (time(NULL) - lastmsgtime >= MAXIDLE) 152 exit(0); 153 (void)alarm((u_int)15); 154 (void)fstat(uf, &statbf); 155 if (statbf.st_mtime > utmpmtime) { 156 utmpmtime = statbf.st_mtime; 157 if (statbf.st_size > utmpsize) { 158 utmpsize = statbf.st_size + 10 * sizeof(struct utmp); 159 if ((utmp = realloc(utmp, utmpsize)) == NULL) { 160 syslog(LOG_ERR, "%s", strerror(errno)); 161 exit(1); 162 } 163 } 164 (void)lseek(uf, (off_t)0, L_SET); 165 nutmp = read(uf, utmp, (int)statbf.st_size)/sizeof(struct utmp); 166 } 167 } 168 169 void 170 mailfor(name) 171 char *name; 172 { 173 register struct utmp *utp = &utmp[nutmp]; 174 register char *cp; 175 char *file; 176 off_t offset; 177 int folder; 178 char buf[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 179 char buf2[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 180 181 if (!(cp = strchr(name, '@'))) 182 return; 183 *cp = '\0'; 184 offset = atoi(cp + 1); 185 if (!(cp = strchr(cp + 1, ':'))) 186 file = name; 187 else 188 file = cp + 1; 189 sprintf(buf, "%s/%.*s", _PATH_MAILDIR, (int)sizeof(utmp[0].ut_name), 190 name); 191 if (*file != '/') { 192 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR, 193 (int)sizeof(utmp[0].ut_name), file); 194 file = buf2; 195 } 196 folder = strcmp(buf, file); 197 while (--utp >= utmp) 198 if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name))) 199 notify(utp, file, offset, folder); 200 } 201 202 static char *cr; 203 204 void 205 notify(utp, file, offset, folder) 206 register struct utmp *utp; 207 char file[]; 208 off_t offset; 209 int folder; 210 { 211 FILE *tp; 212 struct stat stb; 213 struct termios tio; 214 char tty[20], name[sizeof(utmp[0].ut_name) + 1]; 215 216 (void)snprintf(tty, sizeof(tty), "%s%.*s", 217 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line); 218 if (strchr(tty + sizeof(_PATH_DEV) - 1, '/')) { 219 /* A slash is an attempt to break security... */ 220 syslog(LOG_AUTH | LOG_NOTICE, "'/' in \"%s\"", tty); 221 return; 222 } 223 if (stat(tty, &stb) || !(stb.st_mode & (S_IXUSR | S_IXGRP))) { 224 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty); 225 return; 226 } 227 dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty); 228 if (fork()) 229 return; 230 (void)signal(SIGALRM, SIG_DFL); 231 (void)alarm((u_int)30); 232 if ((tp = fopen(tty, "w")) == NULL) { 233 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno)); 234 _exit(1); 235 } 236 (void)tcgetattr(fileno(tp), &tio); 237 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r"; 238 (void)strncpy(name, utp->ut_name, sizeof(utp->ut_name)); 239 name[sizeof(name) - 1] = '\0'; 240 switch (stb.st_mode & (S_IXUSR | S_IXGRP)) { 241 case S_IXUSR: 242 case (S_IXUSR | S_IXGRP): 243 (void)fprintf(tp, 244 "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s", 245 cr, name, (int)sizeof(hostname), hostname, 246 folder ? cr : "", folder ? "to " : "", folder ? file : "", 247 cr, cr); 248 jkfprintf(tp, name, file, offset); 249 break; 250 case S_IXGRP: 251 (void)fprintf(tp, "\007"); 252 (void)fflush(tp); 253 (void)sleep(1); 254 (void)fprintf(tp, "\007"); 255 break; 256 default: 257 break; 258 } 259 (void)fclose(tp); 260 _exit(0); 261 } 262 263 void 264 jkfprintf(tp, user, file, offset) 265 register FILE *tp; 266 char user[]; 267 char file[]; 268 off_t offset; 269 { 270 register unsigned char *cp, ch; 271 register FILE *fi; 272 register int linecnt, charcnt, inheader; 273 register struct passwd *p; 274 unsigned char line[BUFSIZ]; 275 276 /* Set effective uid to user in case mail drop is on nfs */ 277 if ((p = getpwnam(user)) != NULL) 278 (void) setuid(p->pw_uid); 279 280 if ((fi = fopen(file, "r")) == NULL) 281 return; 282 283 (void)fseek(fi, offset, L_SET); 284 /* 285 * Print the first 7 lines or 560 characters of the new mail 286 * (whichever comes first). Skip header crap other than 287 * From, Subject, To, and Date. 288 */ 289 linecnt = 7; 290 charcnt = 560; 291 inheader = 1; 292 while (fgets(line, sizeof(line), fi) != NULL) { 293 if (inheader) { 294 if (line[0] == '\n') { 295 inheader = 0; 296 continue; 297 } 298 if (line[0] == ' ' || line[0] == '\t' || 299 (strncmp(line, "From:", 5) && 300 strncmp(line, "Subject:", 8))) 301 continue; 302 } 303 if (linecnt <= 0 || charcnt <= 0) { 304 (void)fprintf(tp, "...more...%s", cr); 305 (void)fclose(fi); 306 return; 307 } 308 /* strip weird stuff so can't trojan horse stupid terminals */ 309 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 310 /* disable upper controls and enable all other 311 8bit codes due to lack of locale knowledge 312 */ 313 if (((ch & 0x80) && ch < 0xA0) || 314 (!(ch & 0x80) && !isprint(ch) && 315 !isspace(ch) && ch != '\a' && ch != '\b') 316 ) { 317 if (ch & 0x80) { 318 ch &= ~0x80; 319 (void)fputs("M-", tp); 320 } 321 if (iscntrl(ch)) { 322 ch ^= 0x40; 323 (void)fputc('^', tp); 324 } 325 } 326 (void)fputc(ch, tp); 327 } 328 (void)fputs(cr, tp); 329 --linecnt; 330 } 331 (void)fprintf(tp, "----%s\n", cr); 332 (void)fclose(fi); 333 } 334