xref: /titanic_41/usr/src/lib/libc/port/gen/execvp.c (revision 843e19887f64dde75055cf8842fc4db2171eff45)
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 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 /*
34  *	execlp(name, arg,...,0)	(like execl, but does path search)
35  *	execvp(name, argv)	(like execv, but does path search)
36  */
37 #pragma weak execlp = _execlp
38 #pragma weak execvp = _execvp
39 #include "synonyms.h"
40 #include <sys/types.h>
41 #include <unistd.h>
42 #include <string.h>
43 #include <alloca.h>
44 #include <errno.h>
45 #include <limits.h>
46 #include <stdarg.h>
47 #include <stdlib.h>
48 
49 static const char *execat(const char *, const char *, char *);
50 
51 extern  int __xpg4;	/* defined in xpg4.c; 0 if not xpg4-compiled program */
52 
53 /*VARARGS1*/
54 int
55 execlp(const char *name, const char *arg0, ...)
56 {
57 	char **argp;
58 	va_list args;
59 	char **argvec;
60 	int err;
61 	int nargs = 0;
62 	char *nextarg;
63 
64 	/*
65 	 * count the number of arguments in the variable argument list
66 	 * and allocate an argument vector for them on the stack,
67 	 * adding space for a terminating null pointer at the end
68 	 * and one additional space for argv[0] which is no longer
69 	 * counted by the varargs loop.
70 	 */
71 
72 	va_start(args, arg0);
73 
74 	while (va_arg(args, char *) != (char *)0)
75 		nargs++;
76 
77 	va_end(args);
78 
79 	/*
80 	 * load the arguments in the variable argument list
81 	 * into the argument vector and add the terminating null pointer
82 	 */
83 
84 	va_start(args, arg0);
85 	/* workaround for bugid 1242839 */
86 	argvec = alloca((size_t)((nargs + 2) * sizeof (char *)));
87 	nextarg = va_arg(args, char *);
88 	argp = argvec;
89 	*argp++ = (char *)arg0;
90 	while (nargs-- && nextarg != (char *)0) {
91 		*argp = nextarg;
92 		argp++;
93 		nextarg = va_arg(args, char *);
94 	}
95 	va_end(args);
96 	*argp = (char *)0;
97 
98 	/*
99 	 * call execvp()
100 	 */
101 
102 	err = execvp(name, argvec);
103 	return (err);
104 }
105 
106 int
107 execvp(const char *name, char *const *argv)
108 {
109 	const char	*pathstr;
110 	char	fname[PATH_MAX+2];
111 	char	*newargs[256];
112 	int	i;
113 	const char *cp;
114 	unsigned etxtbsy = 1;
115 	int eacces = 0;
116 	char *shpath;
117 	static const char *sun_path = "/bin/sh";
118 	static const char *xpg4_path = "/usr/xpg4/bin/sh";
119 	static const char *shell = "sh";
120 
121 	if (*name == '\0') {
122 		errno = ENOENT;
123 		return (-1);
124 	}
125 	if ((pathstr = getenv("PATH")) == NULL) {
126 		/*
127 		 * XPG4:  pathstr is equivalent to CSPATH, except that
128 		 * :/usr/sbin is appended when root, and pathstr must end
129 		 * with a colon when not root.  Keep these paths in sync
130 		 * with CSPATH in confstr.c.  Note that pathstr must end
131 		 * with a colon when not root so that when name doesn't
132 		 * contain '/', the last call to execat() will result in an
133 		 * attempt to execv name from the current directory.
134 		 */
135 		if (geteuid() == 0 || getuid() == 0) {
136 			if (__xpg4 == 0) {	/* not XPG4 */
137 				pathstr = "/usr/sbin:/usr/ccs/bin:/usr/bin";
138 			} else {		/* XPG4 (CSPATH + /usr/sbin) */
139 		pathstr = "/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:"
140 				"/opt/SUNWspro/bin:/usr/sbin";
141 			}
142 		} else {
143 			if (__xpg4 == 0) {	/* not XPG4 */
144 				pathstr = "/usr/ccs/bin:/usr/bin:";
145 			} else {		/* XPG4 (CSPATH) */
146 				pathstr = "/usr/xpg4/bin:/usr/ccs/bin:"
147 				    "/usr/bin:/opt/SUNWspro/bin:";
148 			}
149 		}
150 	}
151 	cp = strchr(name, '/')? (const char *)"": pathstr;
152 
153 	do {
154 		cp = execat(cp, name, fname);
155 	retry:
156 		/*
157 		 * 4025035 and 4038378
158 		 * if a filename begins with a "-" prepend "./" so that
159 		 * the shell can't interpret it as an option
160 		 */
161 		if (*fname == '-') {
162 			size_t size = strlen(fname) + 1;
163 			if ((size + 2) > sizeof (fname)) {
164 				errno = E2BIG;
165 				return (-1);
166 			}
167 			(void) memmove(fname + 2, fname, size);
168 			fname[0] = '.';
169 			fname[1] = '/';
170 		}
171 		(void) execv(fname, argv);
172 		switch (errno) {
173 		case ENOEXEC:
174 			if (__xpg4 == 0) {	/* not XPG4 */
175 				shpath = (char *)sun_path;
176 			} else {		/* XPG4 */
177 				shpath = (char *)xpg4_path;
178 			}
179 			newargs[0] = (char *)shell;
180 			newargs[1] = fname;
181 			for (i = 1; (newargs[i + 1] = argv[i]) != NULL; ++i) {
182 				if (i >= 254) {
183 					errno = E2BIG;
184 					return (-1);
185 				}
186 			}
187 			(void) execv((const char *)shpath, newargs);
188 			return (-1);
189 		case ETXTBSY:
190 			if (++etxtbsy > 5)
191 				return (-1);
192 			(void) sleep(etxtbsy);
193 			goto retry;
194 		case EACCES:
195 			++eacces;
196 			break;
197 		case ENOMEM:
198 		case E2BIG:
199 		case EFAULT:
200 			return (-1);
201 		}
202 	} while (cp);
203 	if (eacces)
204 		errno = EACCES;
205 	return (-1);
206 }
207 
208 static const char *
209 execat(const char *s1, const char *s2, char *si)
210 {
211 	char	*s;
212 	int cnt = PATH_MAX + 1; /* number of characters in s2 */
213 
214 	s = si;
215 	while (*s1 && *s1 != ':') {
216 		if (cnt > 0) {
217 			*s++ = *s1++;
218 			cnt--;
219 		} else
220 			s1++;
221 	}
222 	if (si != s && cnt > 0) {
223 		*s++ = '/';
224 		cnt--;
225 	}
226 	while (*s2 && cnt > 0) {
227 		*s++ = *s2++;
228 		cnt--;
229 	}
230 	*s = '\0';
231 	return (*s1 ? ++s1: 0);
232 }
233