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 * @(#)comsat.c 8.1 (Berkeley) 6/4/93 30 * $FreeBSD: src/libexec/comsat/comsat.c,v 1.17 2005/02/14 17:42:56 stefanf Exp $ 31 * $DragonFly: src/libexec/comsat/comsat.c,v 1.6 2005/05/03 17:39:03 liamfoy Exp $ 32 */ 33 34 #include <sys/param.h> 35 #include <sys/socket.h> 36 #include <sys/stat.h> 37 #include <sys/file.h> 38 #include <sys/wait.h> 39 40 #include <netinet/in.h> 41 42 #include <ctype.h> 43 #include <err.h> 44 #include <errno.h> 45 #include <netdb.h> 46 #include <paths.h> 47 #include <pwd.h> 48 #include <termios.h> 49 #include <signal.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <sysexits.h> 54 #include <syslog.h> 55 #include <unistd.h> 56 #include <utmp.h> 57 58 int debug = 0; 59 #define dsyslog if (debug) syslog 60 61 #define MAXIDLE 120 62 63 char hostname[MAXHOSTNAMELEN]; 64 struct utmp *utmp = NULL; 65 time_t lastmsgtime; 66 int nutmp, uf; 67 68 void jkfprintf (FILE *, const char *, const char *, off_t); 69 void mailfor (char *); 70 void notify (struct utmp *, char *, off_t, int); 71 void onalrm (int); 72 void reapchildren (int); 73 74 int 75 main(int argc __unused, char **argv __unused) 76 { 77 struct sockaddr_in from; 78 socklen_t fromlen; 79 int cc; 80 char msgbuf[256]; 81 82 /* verify proper invocation */ 83 fromlen = sizeof(from); 84 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) 85 err(1, "getsockname"); 86 openlog("comsat", LOG_PID, LOG_DAEMON); 87 if (chdir(_PATH_MAILDIR)) { 88 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR); 89 recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 90 exit(1); 91 } 92 if ((uf = open(_PATH_UTMP, O_RDONLY, 0)) < 0) { 93 syslog(LOG_ERR, "open: %s: %m", _PATH_UTMP); 94 recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 95 exit(1); 96 } 97 time(&lastmsgtime); 98 gethostname(hostname, sizeof(hostname)); 99 onalrm(0); 100 signal(SIGALRM, onalrm); 101 signal(SIGTTOU, SIG_IGN); 102 signal(SIGCHLD, reapchildren); 103 for (;;) { 104 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 105 if (cc <= 0) { 106 if (errno != EINTR) 107 sleep(1); 108 errno = 0; 109 continue; 110 } 111 if (!nutmp) /* no one has logged in yet */ 112 continue; 113 sigblock(sigmask(SIGALRM)); 114 msgbuf[cc] = '\0'; 115 time(&lastmsgtime); 116 mailfor(msgbuf); 117 sigsetmask(0L); 118 } 119 } 120 121 void 122 reapchildren(int signo __unused) 123 { 124 while (wait3(NULL, WNOHANG, NULL) > 0); 125 } 126 127 void 128 onalrm(int signo __unused) 129 { 130 static u_int utmpsize; /* last malloced size for utmp */ 131 static time_t utmpmtime; /* last modification time for utmp */ 132 struct stat statbf; 133 134 if (time(NULL) - lastmsgtime >= MAXIDLE) 135 exit(EX_OK); 136 alarm((u_int)15); 137 fstat(uf, &statbf); 138 if (statbf.st_mtime > utmpmtime) { 139 utmpmtime = statbf.st_mtime; 140 if (statbf.st_size > utmpsize) { 141 utmpsize = statbf.st_size + 10 * sizeof(struct utmp); 142 if ((utmp = realloc(utmp, utmpsize)) == NULL) { 143 syslog(LOG_ERR, "realloc: %m"); 144 exit(1); 145 } 146 } 147 lseek(uf, (off_t)0, SEEK_SET); 148 nutmp = read(uf, utmp, (size_t)statbf.st_size)/sizeof(struct utmp); 149 } 150 } 151 152 void 153 mailfor(char *name) 154 { 155 struct utmp *utp = &utmp[nutmp]; 156 char *cp; 157 char *file; 158 off_t offset; 159 int folder; 160 char buf[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 161 char buf2[sizeof(_PATH_MAILDIR) + sizeof(utmp[0].ut_name) + 1]; 162 163 if (!(cp = strchr(name, '@'))) 164 return; 165 *cp = '\0'; 166 offset = strtoll(cp + 1, NULL, 10); 167 if (!(cp = strchr(cp + 1, ':'))) 168 file = name; 169 else 170 file = cp + 1; 171 sprintf(buf, "%s/%.*s", _PATH_MAILDIR, (int)sizeof(utmp[0].ut_name), 172 name); 173 if (*file != '/') { 174 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR, 175 (int)sizeof(utmp[0].ut_name), file); 176 file = buf2; 177 } 178 folder = strcmp(buf, file); 179 while (--utp >= utmp) 180 if (!strncmp(utp->ut_name, name, sizeof(utmp[0].ut_name))) 181 notify(utp, file, offset, folder); 182 } 183 184 static const char *cr; 185 186 void 187 notify(struct utmp *utp, char *file, off_t offset, int folder) 188 { 189 FILE *tp; 190 struct stat stb; 191 struct termios tio; 192 char tty[20], name[sizeof(utmp[0].ut_name) + 1]; 193 194 snprintf(tty, sizeof(tty), "%s%.*s", 195 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line); 196 if (strchr(tty + sizeof(_PATH_DEV) - 1, '/')) { 197 /* A slash is an attempt to break security... */ 198 syslog(LOG_AUTH | LOG_NOTICE, "'/' in \"%s\"", tty); 199 return; 200 } 201 if (stat(tty, &stb) || !(stb.st_mode & (S_IXUSR | S_IXGRP))) { 202 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_name, tty); 203 return; 204 } 205 dsyslog(LOG_DEBUG, "notify %s on %s\n", utp->ut_name, tty); 206 if (fork()) 207 return; 208 signal(SIGALRM, SIG_DFL); 209 alarm((u_int)30); 210 if ((tp = fopen(tty, "w")) == NULL) { 211 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno)); 212 _exit(1); 213 } 214 tcgetattr(fileno(tp), &tio); 215 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r"; 216 strncpy(name, utp->ut_name, sizeof(utp->ut_name)); 217 name[sizeof(name) - 1] = '\0'; 218 switch (stb.st_mode & (S_IXUSR | S_IXGRP)) { 219 case S_IXUSR: 220 case (S_IXUSR | S_IXGRP): 221 fprintf(tp, 222 "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s", 223 cr, name, (int)sizeof(hostname), hostname, 224 folder ? cr : "", folder ? "to " : "", folder ? file : "", 225 cr, cr); 226 jkfprintf(tp, name, file, offset); 227 break; 228 case S_IXGRP: 229 fprintf(tp, "\007"); 230 fflush(tp); 231 sleep(1); 232 fprintf(tp, "\007"); 233 break; 234 default: 235 break; 236 } 237 fclose(tp); 238 _exit(EX_OK); 239 } 240 241 void 242 jkfprintf(FILE *tp, const char *user, const char *file, off_t offset) 243 { 244 unsigned char *cp, ch; 245 FILE *fi; 246 int linecnt, charcnt, inheader; 247 struct passwd *p; 248 unsigned char line[BUFSIZ]; 249 250 /* Set effective uid to user in case mail drop is on nfs */ 251 if ((p = getpwnam(user)) != NULL) 252 setuid(p->pw_uid); 253 254 if ((fi = fopen(file, "r")) == NULL) 255 return; 256 257 fseeko(fi, offset, SEEK_SET); 258 /* 259 * Print the first 7 lines or 560 characters of the new mail 260 * (whichever comes first). Skip header crap other than 261 * From, Subject, To, and Date. 262 */ 263 linecnt = 7; 264 charcnt = 560; 265 inheader = 1; 266 while (fgets(line, sizeof(line), fi) != NULL) { 267 if (inheader) { 268 if (line[0] == '\n') { 269 inheader = 0; 270 continue; 271 } 272 if (line[0] == ' ' || line[0] == '\t' || 273 (strncmp(line, "From:", 5) && 274 strncmp(line, "Subject:", 8))) 275 continue; 276 } 277 if (linecnt <= 0 || charcnt <= 0) { 278 fprintf(tp, "...more...%s", cr); 279 fclose(fi); 280 return; 281 } 282 /* strip weird stuff so can't trojan horse stupid terminals */ 283 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 284 /* disable upper controls and enable all other 285 8bit codes due to lack of locale knowledge 286 */ 287 if (((ch & 0x80) && ch < 0xA0) || 288 (!(ch & 0x80) && !isprint(ch) && 289 !isspace(ch) && ch != '\a' && ch != '\b') 290 ) { 291 if (ch & 0x80) { 292 ch &= ~0x80; 293 fputs("M-", tp); 294 } 295 if (iscntrl(ch)) { 296 ch ^= 0x40; 297 fputc('^', tp); 298 } 299 } 300 fputc(ch, tp); 301 } 302 fputs(cr, tp); 303 --linecnt; 304 } 305 fprintf(tp, "----%s\n", cr); 306 fclose(fi); 307 } 308