1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1980, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)comsat.c 8.1 (Berkeley) 6/4/93 32 * $FreeBSD: head/libexec/comsat/comsat.c 326025 2017-11-20 19:49:47Z pfg $ 33 */ 34 35 #include <sys/param.h> 36 #include <sys/socket.h> 37 #include <sys/stat.h> 38 #include <sys/file.h> 39 #include <sys/wait.h> 40 41 #include <netinet/in.h> 42 43 #include <ctype.h> 44 #include <err.h> 45 #include <errno.h> 46 #include <netdb.h> 47 #include <paths.h> 48 #include <pwd.h> 49 #include <termios.h> 50 #include <signal.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <sysexits.h> 55 #include <syslog.h> 56 #include <unistd.h> 57 #include <utmpx.h> 58 59 static int debug = 0; 60 #define dsyslog if (debug) syslog 61 62 #define MAXIDLE 120 63 64 static char hostname[MAXHOSTNAMELEN]; 65 66 static void jkfprintf(FILE *, char[], char[], off_t); 67 static void mailfor(char *); 68 static void notify(struct utmpx *, char[], off_t, int); 69 static void reapchildren(int); 70 71 int 72 main(int argc __unused, char *argv[] __unused) 73 { 74 struct sockaddr_in from; 75 socklen_t fromlen; 76 int cc; 77 char msgbuf[256]; 78 79 /* verify proper invocation */ 80 fromlen = sizeof(from); 81 if (getsockname(0, (struct sockaddr *)&from, &fromlen) < 0) 82 err(1, "getsockname"); 83 openlog("comsat", LOG_PID, LOG_DAEMON); 84 if (chdir(_PATH_MAILDIR)) { 85 syslog(LOG_ERR, "chdir: %s: %m", _PATH_MAILDIR); 86 recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 87 exit(1); 88 } 89 gethostname(hostname, sizeof(hostname)); 90 signal(SIGTTOU, SIG_IGN); 91 signal(SIGCHLD, reapchildren); 92 for (;;) { 93 cc = recv(0, msgbuf, sizeof(msgbuf) - 1, 0); 94 if (cc <= 0) { 95 if (errno != EINTR) 96 sleep(1); 97 errno = 0; 98 continue; 99 } 100 msgbuf[cc] = '\0'; 101 mailfor(msgbuf); 102 sigsetmask(0L); 103 } 104 } 105 106 static void 107 reapchildren(int signo __unused) 108 { 109 while (wait3(NULL, WNOHANG, NULL) > 0); 110 } 111 112 static void 113 mailfor(char *name) 114 { 115 struct utmpx *utp; 116 char *cp; 117 char *file; 118 off_t offset; 119 int folder; 120 char buf[sizeof(_PATH_MAILDIR) + sizeof(utp->ut_user) + 1]; 121 char buf2[sizeof(_PATH_MAILDIR) + sizeof(utp->ut_user) + 1]; 122 123 if (!(cp = strchr(name, '@'))) 124 return; 125 *cp = '\0'; 126 offset = strtoll(cp + 1, NULL, 10); 127 if (!(cp = strchr(cp + 1, ':'))) 128 file = name; 129 else 130 file = cp + 1; 131 sprintf(buf, "%s/%.*s", _PATH_MAILDIR, (int)sizeof(utp->ut_user), 132 name); 133 if (*file != '/') { 134 sprintf(buf2, "%s/%.*s", _PATH_MAILDIR, 135 (int)sizeof(utp->ut_user), file); 136 file = buf2; 137 } 138 folder = strcmp(buf, file); 139 setutxent(); 140 while ((utp = getutxent()) != NULL) 141 if (utp->ut_type == USER_PROCESS && !strcmp(utp->ut_user, name)) 142 notify(utp, file, offset, folder); 143 endutxent(); 144 } 145 146 static const char *cr; 147 148 static void 149 notify(struct utmpx *utp, char file[], off_t offset, int folder) 150 { 151 FILE *tp; 152 struct stat stb; 153 struct termios tio; 154 char tty[20]; 155 const char *s = utp->ut_line; 156 157 if (strncmp(s, "pts/", 4) == 0) 158 s += 4; 159 if (strchr(s, '/')) { 160 /* A slash is an attempt to break security... */ 161 syslog(LOG_AUTH | LOG_NOTICE, "Unexpected `/' in `%s'", 162 utp->ut_line); 163 return; 164 } 165 snprintf(tty, sizeof(tty), "%s%.*s", 166 _PATH_DEV, (int)sizeof(utp->ut_line), utp->ut_line); 167 if (stat(tty, &stb) == -1 || !(stb.st_mode & (S_IXUSR | S_IXGRP))) { 168 dsyslog(LOG_DEBUG, "%s: wrong mode on %s", utp->ut_user, tty); 169 return; 170 } 171 dsyslog(LOG_DEBUG, "notify %s on %s", utp->ut_user, tty); 172 switch (fork()) { 173 case -1: 174 syslog(LOG_NOTICE, "fork failed (%m)"); 175 return; 176 case 0: 177 break; 178 default: 179 return; 180 } 181 if ((tp = fopen(tty, "w")) == NULL) { 182 dsyslog(LOG_ERR, "%s: %s", tty, strerror(errno)); 183 _exit(1); 184 } 185 tcgetattr(fileno(tp), &tio); 186 cr = ((tio.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) ? "\n" : "\n\r"; 187 switch (stb.st_mode & (S_IXUSR | S_IXGRP)) { 188 case S_IXUSR: 189 case (S_IXUSR | S_IXGRP): 190 fprintf(tp, 191 "%s\007New mail for %s@%.*s\007 has arrived%s%s%s:%s----%s", 192 cr, utp->ut_user, (int)sizeof(hostname), hostname, 193 folder ? cr : "", folder ? "to " : "", folder ? file : "", 194 cr, cr); 195 jkfprintf(tp, utp->ut_user, file, offset); 196 break; 197 case S_IXGRP: 198 fprintf(tp, "\007"); 199 fflush(tp); 200 sleep(1); 201 fprintf(tp, "\007"); 202 break; 203 default: 204 break; 205 } 206 fclose(tp); 207 _exit(EX_OK); 208 } 209 210 static void 211 jkfprintf(FILE *tp, char user[], char file[], off_t offset) 212 { 213 unsigned char *cp, ch; 214 FILE *fi; 215 int linecnt, charcnt, inheader; 216 struct passwd *p; 217 unsigned char line[BUFSIZ]; 218 219 /* Set effective uid to user in case mail drop is on nfs */ 220 if ((p = getpwnam(user)) != NULL) 221 setuid(p->pw_uid); 222 223 if ((fi = fopen(file, "r")) == NULL) 224 return; 225 226 fseeko(fi, offset, SEEK_CUR); 227 /* 228 * Print the first 7 lines or 560 characters of the new mail 229 * (whichever comes first). Skip header crap other than 230 * From, Subject, To, and Date. 231 */ 232 linecnt = 7; 233 charcnt = 560; 234 inheader = 1; 235 while (fgets(line, sizeof(line), fi) != NULL) { 236 if (inheader) { 237 if (line[0] == '\n') { 238 inheader = 0; 239 continue; 240 } 241 if (line[0] == ' ' || line[0] == '\t' || 242 (strncmp(line, "From:", 5) && 243 strncmp(line, "Subject:", 8))) 244 continue; 245 } 246 if (linecnt <= 0 || charcnt <= 0) { 247 fprintf(tp, "...more...%s", cr); 248 fclose(fi); 249 return; 250 } 251 /* strip weird stuff so can't trojan horse stupid terminals */ 252 for (cp = line; (ch = *cp) && ch != '\n'; ++cp, --charcnt) { 253 /* disable upper controls and enable all other 254 8bit codes due to lack of locale knowledge 255 */ 256 if (((ch & 0x80) && ch < 0xA0) || 257 (!(ch & 0x80) && !isprint(ch) && 258 !isspace(ch) && ch != '\a' && ch != '\b') 259 ) { 260 if (ch & 0x80) { 261 ch &= ~0x80; 262 fputs("M-", tp); 263 } 264 if (iscntrl(ch)) { 265 ch ^= 0x40; 266 fputc('^', tp); 267 } 268 } 269 fputc(ch, tp); 270 } 271 fputs(cr, tp); 272 --linecnt; 273 } 274 fprintf(tp, "----%s\n", cr); 275 fclose(fi); 276 } 277