xref: /illumos-gate/usr/src/cmd/mail/main.c (revision ddb365bfc9e868ad24ccdcb0dc91af18b10df082)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #include "mail.h"
31 #ifdef SVR4
32 #include <locale.h>
33 #endif
34 /*
35  *	mail [ -ehpPqrtw ] [-x debuglevel] [ -f file ] [ -F user(s) ]
36  *	mail -T file persons
37  *	mail [ -tw ] [ -m messagetype ] persons
38  *	rmail [ -tw ] persons
39  */
40 int
41 main(int argc, char **argv)
42 {
43 	register int i;
44 	char *cptr, *p;
45 	struct stat statb;
46 	static char pn[] = "main";
47 	extern char **environ;
48 	int env_var_idx, next_slot_idx;
49 	int tmpfd = -1;
50 
51 #ifdef SVR4
52 	(void) setlocale(LC_ALL, "");
53 #endif
54 	/* fix here for bug #1086130 - security hole	*/
55 	/* skip over the LD_* env variable		*/
56 	env_var_idx = 0; next_slot_idx = 0;
57 	while (environ[env_var_idx] != NULL) {
58 			environ[next_slot_idx] = environ[env_var_idx];
59 		if (strncmp(environ[env_var_idx], "LD_", 3)) {
60 			next_slot_idx++;
61 		}
62 		env_var_idx++;
63 	}
64 	environ[next_slot_idx] = NULL;
65 
66 #ifdef SIGCONT
67 #ifdef SVR4
68 	{
69 	struct sigaction nsig;
70 	nsig.sa_handler = SIG_DFL;
71 	sigemptyset(&nsig.sa_mask);
72 	nsig.sa_flags = SA_RESTART;
73 	(void) sigaction(SIGCONT, &nsig, (struct sigaction *)0);
74 	}
75 #else
76 	sigset(SIGCONT, SIG_DFL);
77 #endif
78 #endif
79 
80 	/*
81 	 *	Strip off path name of this command for use in messages
82 	 */
83 	if ((program = strrchr(argv[0], '/')) != NULL) {
84 		program++;
85 	} else {
86 		program = argv[0];
87 	}
88 
89 	/* Close all file descriptors except stdin, stdout & stderr */
90 	closefrom(STDERR_FILENO + 1);
91 
92 	/*
93 	 *	Get group id for mail, exit if none exists
94 	 */
95 	if ((grpptr = getgrnam("mail")) == NULL) {
96 		errmsg(E_GROUP, "");
97 		exit(1);
98 	} else {
99 		mailgrp = grpptr->gr_gid;
100 	}
101 
102 	/*
103 	 *	Save the *id for later use.
104 	 */
105 	my_uid = getuid();
106 	my_gid = getgid();
107 	my_euid = geteuid();
108 	my_egid = getegid();
109 
110 	/*
111 	 *	What command (rmail or mail)?
112 	 */
113 	if (strcmp(program, "rmail") == SAME) {
114 		ismail = FALSE;
115 	}
116 
117 	/*
118 	 *	Parse the command line and adjust argc and argv
119 	 *	to compensate for any options
120 	 */
121 	i = parse(argc, argv);
122 	argv += (i - 1);
123 	argc -= (i - 1);
124 
125 	/* block a potential security hole */
126 	if (flgT && (my_euid != 0)) {
127 		setgid(my_gid);
128 		Tout(pn, "Setgid unset\n");
129 	}
130 
131 	if (debug == 0) {
132 		/* If not set as an invocation option, check for system-wide */
133 		/* global flag */
134 		char *xp = xgetenv("DEBUG");
135 		if (xp != (char *)NULL) {
136 			debug = atoi(xp);
137 			if (debug < 0) {
138 				/* Keep trace file even if successful */
139 				keepdbgfile = -1;
140 				debug = -debug;
141 			}
142 		}
143 	}
144 	if (debug > 0) {
145 		strcpy(dbgfname, "/tmp/MLDBGXXXXXX");
146 		if ((tmpfd = mkstemp(dbgfname)) == -1) {
147 			fprintf(stderr, "%s: can't open debugging file '%s'\n",
148 				program, dbgfname);
149 			exit(13);
150 		}
151 		if ((dbgfp = fdopen(tmpfd, "w")) == (FILE *)NULL) {
152 			fprintf(stderr, "%s: can't open debugging file '%s'\n",
153 				program, dbgfname);
154 			(void) close(tmpfd);
155 			exit(13);
156 		}
157 		setbuf(dbgfp, NULL);
158 		fprintf(dbgfp, "main(): debugging level == %d\n", debug);
159 		fprintf(dbgfp, "main(): trace file ='%s': kept %s\n", dbgfname,
160 			((keepdbgfile < 0) ?
161 				"on success or failure." : "only on failure."));
162 	}
163 
164 	if (!ismail && (goerr > 0 || !i)) {
165 		Dout(pn, 11, "!ismail, goerr=%d, i=%d\n", goerr, i);
166 		if (goerr > 0) {
167 			errmsg(E_SYNTAX, "Usage: rmail [-wt] person(s)");
168 		}
169 		if (!i) {
170 			errmsg(E_SYNTAX, "At least one user must be specified");
171 		}
172 		Dout(pn, 11, "exiting!\n");
173 		done(0);
174 	}
175 
176 	umsave = umask(7);
177 	uname(&utsn);
178 	if ((p = xgetenv("CLUSTER")) != (char *)NULL) {
179 		/*
180 		 * We are not who we appear...
181 		 */
182 		thissys = p;
183 	} else {
184 		thissys = utsn.nodename;
185 	}
186 	Dout(pn, 11, "thissys = '%s', uname = '%s'\n", thissys, utsn.nodename);
187 
188 	failsafe = xgetenv("FAILSAFE");
189 	if (failsafe)
190 		Dout(pn, 11, "failsafe processing enabled to %s\n", failsafe);
191 
192 	/*
193 	 *	Use environment variables
194 	 */
195 	home = getenv("HOME");
196 	if (!home || !*home) {
197 		home = ".";
198 	}
199 
200 	my_name[0] = '\0';
201 	pwd = getpwuid(my_uid);
202 	if (pwd)
203 		(void) strlcpy(my_name, pwd->pw_name, sizeof (my_name));
204 
205 	/* If root, use LOGNAME if set */
206 	if (my_uid == 0) {
207 		/* If root, use LOGNAME if set */
208 		if (((cptr = getenv("LOGNAME")) != NULL) &&
209 		    (strlen(cptr) != 0)) {
210 			(void) strlcpy(my_name, cptr, sizeof (my_name));
211 		}
212 	}
213 	Dout(pn, 11, "my_name = '%s'\n", my_name);
214 
215 	/*
216 	 *	Catch signals for cleanup
217 	 */
218 	if (setjmp(sjbuf)) {
219 		done(0);
220 	}
221 	for (i = SIGINT; i < SIGCLD; i++) {
222 		setsig(i, delete);
223 	}
224 	setsig(SIGHUP, sig_done);
225 	setsig(SIGTERM, sig_done);
226 
227 	cksaved(my_name);
228 
229 	/*
230 	 *	Rmail is always invoked to send mail
231 	 */
232 	Dout(pn, 11, "ismail=%d, argc=%d\n", ismail, argc);
233 	if (ismail && (argc == 1)) {
234 		sending = FALSE;
235 		printmail();
236 
237 	} else {
238 		sending = TRUE;
239 		sendmail(argc, argv);
240 	}
241 	done(0);
242 }
243