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 * @(#) Copyright (c) 1980, 1993 The Regents of the University of California. All rights reserved. 34 * @(#)comsat.c 8.1 (Berkeley) 6/4/93 35 * $FreeBSD: src/libexec/comsat/comsat.c,v 1.13.2.1 2002/08/09 02:56:30 johan Exp $ 36 * $DragonFly: src/libexec/comsat/comsat.c,v 1.6 2005/05/03 17:39:03 liamfoy Exp $ 37 */ 38 39 #include <sys/param.h> 40 #include <sys/socket.h> 41 #include <sys/stat.h> 42 #include <sys/file.h> 43 #include <sys/wait.h> 44 45 #include <netinet/in.h> 46 47 #include <ctype.h> 48 #include <err.h> 49 #include <errno.h> 50 #include <netdb.h> 51 #include <paths.h> 52 #include <pwd.h> 53 #include <termios.h> 54 #include <signal.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <sysexits.h> 59 #include <syslog.h> 60 #include <unistd.h> 61 #include <utmp.h> 62 63 int debug = 0; 64 #define dsyslog if (debug) syslog 65 66 #define MAXIDLE 120 67 68 char hostname[MAXHOSTNAMELEN]; 69 struct utmp *utmp = NULL; 70 time_t lastmsgtime; 71 int nutmp, uf; 72 73 void jkfprintf (FILE *, const char *, const char *, off_t); 74 void mailfor (char *); 75 void notify (struct utmp *, char *, off_t, int); 76 void onalrm (int); 77 void reapchildren (int); 78 79 int 80 main(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 recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 95 exit(1); 96 } 97 if ((uf = open(_PATH_UTMP, O_RDONLY, 0)) < 0) { 98 syslog(LOG_ERR, "open: %s: %m", _PATH_UTMP); 99 recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 100 exit(1); 101 } 102 time(&lastmsgtime); 103 gethostname(hostname, sizeof(hostname)); 104 onalrm(0); 105 signal(SIGALRM, onalrm); 106 signal(SIGTTOU, SIG_IGN); 107 signal(SIGCHLD, reapchildren); 108 for (;;) { 109 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 110 if (cc <= 0) { 111 if (errno != EINTR) 112 sleep(1); 113 errno = 0; 114 continue; 115 } 116 if (!nutmp) /* no one has logged in yet */ 117 continue; 118 sigblock(sigmask(SIGALRM)); 119 msgbuf[cc] = '\0'; 120 time(&lastmsgtime); 121 mailfor(msgbuf); 122 sigsetmask(0L); 123 } 124 } 125 126 void 127 reapchildren(int signo __unused) 128 { 129 while (wait3(NULL, WNOHANG, NULL) > 0); 130 } 131 132 void 133 onalrm(int signo __unused) 134 { 135 static u_int utmpsize; /* last malloced size for utmp */ 136 static time_t utmpmtime; /* last modification time for utmp */ 137 struct stat statbf; 138 139 if (time(NULL) - lastmsgtime >= MAXIDLE) 140 exit(EX_OK); 141 alarm((u_int)15); 142 fstat(uf, &statbf); 143 if (statbf.st_mtime > utmpmtime) { 144 utmpmtime = statbf.st_mtime; 145 if (statbf.st_size > utmpsize) { 146 utmpsize = statbf.st_size + 10 * sizeof(struct utmp); 147 if ((utmp = realloc(utmp, utmpsize)) == NULL) { 148 syslog(LOG_ERR, "realloc: %m"); 149 exit(1); 150 } 151 } 152 lseek(uf, (off_t)0, L_SET); 153 nutmp = read(uf, utmp, (int)statbf.st_size)/sizeof(struct utmp); 154 } 155 } 156 157 void 158 mailfor(char *name) 159 { 160 struct utmp *utp = &utmp[nutmp]; 161 char *cp; 162 char *file; 163 off_t offset; 164 int folder; 165 char buf[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 166 char buf2[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 167 168 if (!(cp = strchr(name, '@'))) 169 return; 170 *cp = '\0'; 171 offset = atoi(cp + 1); 172 if (!(cp = strchr(cp + 1, ':'))) 173 file = name; 174 else 175 file = cp + 1; 176 sprintf(buf, "%s/%.*s", _PATH_MAILDIR, (int)sizeof(utmp[0].ut_name), 177 name); 178 if (*file != '/') { 179 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR, 180 (int)sizeof(utmp[0].ut_name), file); 181 file = buf2; 182 } 183 folder = strcmp(buf, file); 184 while (--utp >= utmp) 185 if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name))) 186 notify(utp, file, offset, folder); 187 } 188 189 static const char *cr; 190 191 void 192 notify(struct utmp *utp, char *file, off_t offset, int folder) 193 { 194 FILE *tp; 195 struct stat stb; 196 struct termios tio; 197 char tty[20], name[sizeof(utmp[0].ut_name) + 1]; 198 199 snprintf(tty, sizeof(tty), "%s%.*s", 200 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line); 201 if (strchr(tty + sizeof(_PATH_DEV) - 1, '/')) { 202 /* A slash is an attempt to break security... */ 203 syslog(LOG_AUTH | LOG_NOTICE, "'/' in \"%s\"", tty); 204 return; 205 } 206 if (stat(tty, &stb) || !(stb.st_mode & (S_IXUSR | S_IXGRP))) { 207 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty); 208 return; 209 } 210 dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty); 211 if (fork()) 212 return; 213 signal(SIGALRM, SIG_DFL); 214 alarm((u_int)30); 215 if ((tp = fopen(tty, "w")) == NULL) { 216 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno)); 217 _exit(1); 218 } 219 tcgetattr(fileno(tp), &tio); 220 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r"; 221 strncpy(name, utp->ut_name, sizeof(utp->ut_name)); 222 name[sizeof(name) - 1] = '\0'; 223 switch (stb.st_mode & (S_IXUSR | S_IXGRP)) { 224 case S_IXUSR: 225 case (S_IXUSR | S_IXGRP): 226 fprintf(tp, 227 "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s", 228 cr, name, (int)sizeof(hostname), hostname, 229 folder ? cr : "", folder ? "to " : "", folder ? file : "", 230 cr, cr); 231 jkfprintf(tp, name, file, offset); 232 break; 233 case S_IXGRP: 234 fprintf(tp, "\007"); 235 fflush(tp); 236 sleep(1); 237 fprintf(tp, "\007"); 238 break; 239 default: 240 break; 241 } 242 fclose(tp); 243 _exit(EX_OK); 244 } 245 246 void 247 jkfprintf(FILE *tp, const char *user, const char *file, off_t offset) 248 { 249 unsigned char *cp, ch; 250 FILE *fi; 251 int linecnt, charcnt, inheader; 252 struct passwd *p; 253 unsigned char line[BUFSIZ]; 254 255 /* Set effective uid to user in case mail drop is on nfs */ 256 if ((p = getpwnam(user)) != NULL) 257 setuid(p->pw_uid); 258 259 if ((fi = fopen(file, "r")) == NULL) 260 return; 261 262 fseek(fi, offset, L_SET); 263 /* 264 * Print the first 7 lines or 560 characters of the new mail 265 * (whichever comes first). Skip header crap other than 266 * From, Subject, To, and Date. 267 */ 268 linecnt = 7; 269 charcnt = 560; 270 inheader = 1; 271 while (fgets(line, sizeof(line), fi) != NULL) { 272 if (inheader) { 273 if (line[0] == '\n') { 274 inheader = 0; 275 continue; 276 } 277 if (line[0] == ' ' || line[0] == '\t' || 278 (strncmp(line, "From:", 5) && 279 strncmp(line, "Subject:", 8))) 280 continue; 281 } 282 if (linecnt <= 0 || charcnt <= 0) { 283 fprintf(tp, "...more...%s", cr); 284 fclose(fi); 285 return; 286 } 287 /* strip weird stuff so can't trojan horse stupid terminals */ 288 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 289 /* disable upper controls and enable all other 290 8bit codes due to lack of locale knowledge 291 */ 292 if (((ch & 0x80) && ch < 0xA0) || 293 (!(ch & 0x80) && !isprint(ch) && 294 !isspace(ch) && ch != '\a' && ch != '\b') 295 ) { 296 if (ch & 0x80) { 297 ch &= ~0x80; 298 fputs("M-", tp); 299 } 300 if (iscntrl(ch)) { 301 ch ^= 0x40; 302 fputc('^', tp); 303 } 304 } 305 fputc(ch, tp); 306 } 307 fputs(cr, tp); 308 --linecnt; 309 } 310 fprintf(tp, "----%s\n", cr); 311 fclose(fi); 312 } 313