xref: /illumos-gate/usr/src/cmd/mail/main.c (revision a38ddfee9c8c6b6c5a2947ff52fd2338362a4444)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #include "mail.h"
33 #ifdef SVR4
34 #include <locale.h>
35 #endif
36 /*
37  *	mail [ -ehpPqrtw ] [-x debuglevel] [ -f file ] [ -F user(s) ]
38  *	mail -T file persons
39  *	mail [ -tw ] [ -m messagetype ] persons
40  *	rmail [ -tw ] persons
41  */
42 int
43 main(int argc, char **argv)
44 {
45 	register int i;
46 	char *cptr, *p;
47 	struct stat statb;
48 	static char pn[] = "main";
49 	extern char **environ;
50 	int env_var_idx, next_slot_idx;
51 	int tmpfd = -1;
52 
53 #ifdef SVR4
54 	(void) setlocale(LC_ALL, "");
55 #endif
56 	/* fix here for bug #1086130 - security hole	*/
57 	/* skip over the LD_* env variable		*/
58 	env_var_idx = 0; next_slot_idx = 0;
59 	while (environ[env_var_idx] != NULL) {
60 			environ[next_slot_idx] = environ[env_var_idx];
61 		if (strncmp(environ[env_var_idx], "LD_", 3)) {
62 			next_slot_idx++;
63 		}
64 		env_var_idx++;
65 	}
66 	environ[next_slot_idx] = NULL;
67 
68 #ifdef SIGCONT
69 #ifdef SVR4
70 	{
71 	struct sigaction nsig;
72 	nsig.sa_handler = SIG_DFL;
73 	sigemptyset(&nsig.sa_mask);
74 	nsig.sa_flags = SA_RESTART;
75 	(void) sigaction(SIGCONT, &nsig, (struct sigaction *)0);
76 	}
77 #else
78 	sigset(SIGCONT, SIG_DFL);
79 #endif
80 #endif
81 
82 	/*
83 	 *	Strip off path name of this command for use in messages
84 	 */
85 	if ((program = strrchr(argv[0], '/')) != NULL) {
86 		program++;
87 	} else {
88 		program = argv[0];
89 	}
90 
91 	/* Close all file descriptors except stdin, stdout & stderr */
92 	closefrom(STDERR_FILENO + 1);
93 
94 	/*
95 	 *	Get group id for mail, exit if none exists
96 	 */
97 	if ((grpptr = getgrnam("mail")) == NULL) {
98 		errmsg(E_GROUP, "");
99 		exit(1);
100 	} else {
101 		mailgrp = grpptr->gr_gid;
102 	}
103 
104 	/*
105 	 *	Save the *id for later use.
106 	 */
107 	my_uid = getuid();
108 	my_gid = getgid();
109 	my_euid = geteuid();
110 	my_egid = getegid();
111 
112 	/*
113 	 *	What command (rmail or mail)?
114 	 */
115 	if (strcmp(program, "rmail") == SAME) {
116 		ismail = FALSE;
117 	}
118 
119 	/*
120 	 *	Parse the command line and adjust argc and argv
121 	 *	to compensate for any options
122 	 */
123 	i = parse(argc, argv);
124 	argv += (i - 1);
125 	argc -= (i - 1);
126 
127 	/* block a potential security hole */
128 	if (flgT && (my_euid != 0)) {
129 		setgid(my_gid);
130 		Tout(pn, "Setgid unset\n");
131 	}
132 
133 	if (debug == 0) {
134 		/* If not set as an invocation option, check for system-wide */
135 		/* global flag */
136 		char *xp = xgetenv("DEBUG");
137 		if (xp != (char *)NULL) {
138 			debug = atoi(xp);
139 			if (debug < 0) {
140 				/* Keep trace file even if successful */
141 				keepdbgfile = -1;
142 				debug = -debug;
143 			}
144 		}
145 	}
146 	if (debug > 0) {
147 		strcpy(dbgfname, "/tmp/MLDBGXXXXXX");
148 		if ((tmpfd = mkstemp(dbgfname)) == -1) {
149 			fprintf(stderr, "%s: can't open debugging file '%s'\n",
150 				program, dbgfname);
151 			exit(13);
152 		}
153 		if ((dbgfp = fdopen(tmpfd, "w")) == (FILE *)NULL) {
154 			fprintf(stderr, "%s: can't open debugging file '%s'\n",
155 				program, dbgfname);
156 			(void) close(tmpfd);
157 			exit(13);
158 		}
159 		setbuf(dbgfp, NULL);
160 		fprintf(dbgfp, "main(): debugging level == %d\n", debug);
161 		fprintf(dbgfp, "main(): trace file ='%s': kept %s\n", dbgfname,
162 			((keepdbgfile < 0) ?
163 				"on success or failure." : "only on failure."));
164 	}
165 
166 	if (!ismail && (goerr > 0 || !i)) {
167 		Dout(pn, 11, "!ismail, goerr=%d, i=%d\n", goerr, i);
168 		if (goerr > 0) {
169 			errmsg(E_SYNTAX, "Usage: rmail [-wt] person(s)");
170 		}
171 		if (!i) {
172 			errmsg(E_SYNTAX, "At least one user must be specified");
173 		}
174 		Dout(pn, 11, "exiting!\n");
175 		done(0);
176 	}
177 
178 	umsave = umask(7);
179 	uname(&utsn);
180 	if ((p = xgetenv("CLUSTER")) != (char *)NULL) {
181 		/*
182 		 * We are not who we appear...
183 		 */
184 		thissys = p;
185 	} else {
186 		thissys = utsn.nodename;
187 	}
188 	Dout(pn, 11, "thissys = '%s', uname = '%s'\n", thissys, utsn.nodename);
189 
190 	failsafe = xgetenv("FAILSAFE");
191 	if (failsafe)
192 		Dout(pn, 11, "failsafe processing enabled to %s\n", failsafe);
193 
194 	/*
195 	 *	Use environment variables
196 	 */
197 	home = getenv("HOME");
198 	if (!home || !*home) {
199 		home = ".";
200 	}
201 
202 	my_name[0] = '\0';
203 	pwd = getpwuid(my_uid);
204 	if (pwd)
205 		(void) strlcpy(my_name, pwd->pw_name, sizeof (my_name));
206 
207 	/* If root, use LOGNAME if set */
208 	if (my_uid == 0) {
209 		/* If root, use LOGNAME if set */
210 		if (((cptr = getenv("LOGNAME")) != NULL) &&
211 		    (strlen(cptr) != 0)) {
212 			(void) strlcpy(my_name, cptr, sizeof (my_name));
213 		}
214 	}
215 	Dout(pn, 11, "my_name = '%s'\n", my_name);
216 
217 	/*
218 	 *	Catch signals for cleanup
219 	 */
220 	if (setjmp(sjbuf)) {
221 		done(0);
222 	}
223 	for (i = SIGINT; i < SIGCLD; i++) {
224 		setsig(i, delete);
225 	}
226 	setsig(SIGHUP, sig_done);
227 	setsig(SIGTERM, sig_done);
228 
229 	cksaved(my_name);
230 
231 	/*
232 	 *	Rmail is always invoked to send mail
233 	 */
234 	Dout(pn, 11, "ismail=%d, argc=%d\n", ismail, argc);
235 	if (ismail && (argc == 1)) {
236 		sending = FALSE;
237 		printmail();
238 
239 	} else {
240 		sending = TRUE;
241 		sendmail(argc, argv);
242 	}
243 	done(0);
244 }
245