xref: /openbsd/usr.bin/bgplg/misc.c (revision 91f110e0)
1 /*	$OpenBSD: misc.c,v 1.6 2013/11/25 18:02:50 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 2005, 2006 Reyk Floeter <reyk@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/stat.h>
20 #include <sys/types.h>
21 #include <sys/utsname.h>
22 #include <sys/wait.h>
23 #include <sys/time.h>
24 
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <signal.h>
28 #include <string.h>
29 #include <unistd.h>
30 #include <ctype.h>
31 #include <errno.h>
32 #include <fcntl.h>
33 
34 #include "bgplg.h"
35 
36 static volatile pid_t child = -1;
37 
38 int
39 lg_show_version(struct cmd *cmds, char **argv)
40 {
41 	struct utsname uts;
42 	if (uname(&uts) >= 0)
43 		printf("%s %s (%s)\n\n", uts.sysname, uts.release, uts.machine);
44 	printf("%s - %s\n", NAME, BRIEF);
45 	return (0);
46 }
47 
48 int
49 lg_checkperm(struct cmd *cmd)
50 {
51 	struct stat stbuf;
52 
53 	/* No external command to execute, this is always valid */
54 	if (cmd->earg == NULL || cmd->earg[0] == NULL)
55 		return (1);
56 
57 	/*
58 	 * Skip commands if the executable is missing or
59 	 * the permission mode has been set to zero (the default
60 	 * in a CGI environment).
61 	 */
62 	if (stat(cmd->earg[0], &stbuf) != 0 ||
63 	    (stbuf.st_mode & ~S_IFMT) == 0)
64 		return (0);
65 
66 	return (1);
67 }
68 
69 int
70 lg_help(struct cmd *cmds, char **argv)
71 {
72 	u_int i;
73 
74 	printf("valid commands:\n");
75 	for (i = 0; cmds[i].name != NULL; i++) {
76 		if (!lg_checkperm(&cmds[i]))
77 			continue;
78 
79 		printf("  %s", cmds[i].name);
80 		if (cmds[i].minargs > 0)
81 			printf(" { arg }");
82 		else if (cmds[i].maxargs > 0)
83 			printf(" [ arg ]");
84 		printf("\n");
85 	}
86 	return (0);
87 }
88 
89 void
90 lg_sig_alarm(int sig)
91 {
92 	if (child != -1) {
93 		/* Forcibly kill the child, no excuse... */
94 		kill(child, SIGKILL);
95 	}
96 }
97 
98 int
99 lg_exec(const char *file, char **new_argv)
100 {
101 	int status = 0, ret = 0;
102 	sig_t save_quit, save_int, save_chld;
103 	struct itimerval it;
104 
105 	if (new_argv == NULL)
106 		return (EFAULT);
107 
108 	save_quit = signal(SIGQUIT, SIG_IGN);
109 	save_int = signal(SIGINT, SIG_IGN);
110 	save_chld = signal(SIGCHLD, SIG_DFL);
111 
112 	switch (child = fork()) {
113 	case -1:
114 		ret = errno;
115 		goto done;
116 	case 0:
117 		signal(SIGQUIT, SIG_DFL);
118 		signal(SIGINT, SIG_DFL);
119 		signal(SIGCHLD, SIG_DFL);
120 
121 		execvp(file, new_argv);
122 		_exit(127);
123 		break;
124 	default:
125 		/* Kill the process after a timeout */
126 		signal(SIGALRM, lg_sig_alarm);
127 		bzero(&it, sizeof(it));
128 		it.it_value.tv_sec = BGPLG_TIMEOUT;
129 		setitimer(ITIMER_REAL, &it, NULL);
130 
131 		waitpid(child, &status, 0);
132 		break;
133 	}
134 
135 	switch (ret) {
136 	case -1:
137 		ret = ECHILD;
138 		break;
139 	default:
140 		if (WIFEXITED(status))
141 			ret = WEXITSTATUS(status);
142 		else
143 			ret = ECHILD;
144 	}
145 
146  done:
147 	/* Disable the process timeout timer */
148 	bzero(&it, sizeof(it));
149 	setitimer(ITIMER_REAL, &it, NULL);
150 	child = -1;
151 
152 	signal(SIGQUIT, save_quit);
153 	signal(SIGINT, save_int);
154 	signal(SIGCHLD, save_chld);
155 	signal(SIGALRM, SIG_DFL);
156 
157 	return (ret);
158 }
159 
160 ssize_t
161 lg_strip(char *str)
162 {
163 	size_t len;
164 
165 	if ((len = strlen(str)) < 1)
166 		return (0); /* XXX EINVAL? */
167 
168 	if (isspace((unsigned char)str[len - 1])) {
169 		str[len - 1] = '\0';
170 		return (lg_strip(str));
171 	}
172 
173 	return (strlen(str));
174 }
175