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 * $Id$ 34 */ 35 36 #ifndef lint 37 static char copyright[] = 38 "@(#) Copyright (c) 1980, 1993\n\ 39 The Regents of the University of California. All rights reserved.\n"; 40 #endif /* not lint */ 41 42 #ifndef lint 43 static char sccsid[] = "@(#)comsat.c 8.1 (Berkeley) 6/4/93"; 44 #endif /* not lint */ 45 46 #include <sys/param.h> 47 #include <sys/socket.h> 48 #include <sys/stat.h> 49 #include <sys/file.h> 50 #include <sys/wait.h> 51 52 #include <netinet/in.h> 53 54 #include <ctype.h> 55 #include <errno.h> 56 #include <netdb.h> 57 #include <paths.h> 58 #include <pwd.h> 59 #include <termios.h> 60 #include <signal.h> 61 #include <stdio.h> 62 #include <stdlib.h> 63 #include <string.h> 64 #include <syslog.h> 65 #include <unistd.h> 66 #include <utmp.h> 67 68 int debug = 0; 69 #define dsyslog if (debug) syslog 70 71 #define MAXIDLE 120 72 73 char hostname[MAXHOSTNAMELEN]; 74 struct utmp *utmp = NULL; 75 time_t lastmsgtime; 76 int nutmp, uf; 77 78 void jkfprintf __P((FILE *, char[], char[], off_t)); 79 void mailfor __P((char *)); 80 void notify __P((struct utmp *, char[], off_t, int)); 81 void onalrm __P((int)); 82 void reapchildren __P((int)); 83 84 int 85 main(argc, argv) 86 int argc; 87 char *argv[]; 88 { 89 struct sockaddr_in from; 90 register int cc; 91 int fromlen; 92 char msgbuf[256]; 93 94 /* verify proper invocation */ 95 fromlen = sizeof(from); 96 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) { 97 (void)fprintf(stderr, 98 "comsat: getsockname: %s.\n", strerror(errno)); 99 exit(1); 100 } 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, sizeof(utmp[0].ut_name), name); 190 if (*file != '/') { 191 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR, sizeof(utmp[0].ut_name), file); 192 file = buf2; 193 } 194 folder = strcmp(buf, file); 195 while (--utp >= utmp) 196 if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name))) 197 notify(utp, file, offset, folder); 198 } 199 200 static char *cr; 201 202 void 203 notify(utp, file, offset, folder) 204 register struct utmp *utp; 205 char file[]; 206 off_t offset; 207 int folder; 208 { 209 FILE *tp; 210 struct stat stb; 211 struct termios tio; 212 char tty[20], name[sizeof(utmp[0].ut_name) + 1]; 213 214 (void)snprintf(tty, sizeof(tty), "%s%.*s", 215 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line); 216 if (strchr(tty + sizeof(_PATH_DEV) - 1, '/')) { 217 /* A slash is an attempt to break security... */ 218 syslog(LOG_AUTH | LOG_NOTICE, "'/' in \"%s\"", tty); 219 return; 220 } 221 if (stat(tty, &stb) || !(stb.st_mode & S_IEXEC)) { 222 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty); 223 return; 224 } 225 dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty); 226 if (fork()) 227 return; 228 (void)signal(SIGALRM, SIG_DFL); 229 (void)alarm((u_int)30); 230 if ((tp = fopen(tty, "w")) == NULL) { 231 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno)); 232 _exit(-1); 233 } 234 (void)tcgetattr(fileno(tp), &tio); 235 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r"; 236 (void)strncpy(name, utp->ut_name, sizeof(utp->ut_name)); 237 name[sizeof(name) - 1] = '\0'; 238 (void)fprintf(tp, "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s", 239 cr, name, (int)sizeof(hostname), hostname, 240 folder ? cr : "", folder ? "to " : "", folder ? file : "", 241 cr, cr); 242 jkfprintf(tp, name, file, offset); 243 (void)fclose(tp); 244 _exit(0); 245 } 246 247 void 248 jkfprintf(tp, user, file, offset) 249 register FILE *tp; 250 char user[]; 251 char file[]; 252 off_t offset; 253 { 254 register char *cp, ch; 255 register FILE *fi; 256 register int linecnt, charcnt, inheader; 257 register struct passwd *p; 258 char line[BUFSIZ]; 259 260 /* Set effective uid to user in case mail drop is on nfs */ 261 if ((p = getpwnam(user)) != NULL) 262 (void) setuid(p->pw_uid); 263 264 if ((fi = fopen(file, "r")) == NULL) 265 return; 266 267 (void)fseek(fi, offset, L_SET); 268 /* 269 * Print the first 7 lines or 560 characters of the new mail 270 * (whichever comes first). Skip header crap other than 271 * From, Subject, To, and Date. 272 */ 273 linecnt = 7; 274 charcnt = 560; 275 inheader = 1; 276 while (fgets(line, sizeof(line), fi) != NULL) { 277 if (inheader) { 278 if (line[0] == '\n') { 279 inheader = 0; 280 continue; 281 } 282 if (line[0] == ' ' || line[0] == '\t' || 283 strncmp(line, "From:", 5) && 284 strncmp(line, "Subject:", 8)) 285 continue; 286 } 287 if (linecnt <= 0 || charcnt <= 0) { 288 (void)fprintf(tp, "...more...%s", cr); 289 (void)fclose(fi); 290 return; 291 } 292 /* strip weird stuff so can't trojan horse stupid terminals */ 293 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 294 if (!isprint(ch)) { 295 if (ch & 0x80) 296 (void)fputs("M-", tp); 297 ch &= 0177; 298 if (!isprint(ch)) { 299 if (ch == 0177) 300 ch = '?'; 301 else 302 ch |= 0x40; 303 (void)fputc('^', tp); 304 } 305 } 306 (void)fputc(ch, tp); 307 } 308 (void)fputs(cr, tp); 309 --linecnt; 310 } 311 (void)fprintf(tp, "----%s\n", cr); 312 (void)fclose(fi); 313 } 314