xref: /dragonfly/usr.sbin/resident/resident.c (revision e65bc1c3) 
1 /*
2  * Copyright (c) 2003 Matthew Dillon <dillon@backplane.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/param.h>
28 #include <sys/wait.h>
29 #include <sys/stat.h>
30 #include <sys/resident.h>
31 #include <sys/sysctl.h>
32 
33 #include <machine/elf.h>
34 #include <a.out.h>
35 #include <dlfcn.h>
36 #include <err.h>
37 #include <fcntl.h>
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <unistd.h>
41 #include <string.h>
42 #include <errno.h>
43 
44 static void
45 usage(void)
46 {
47 	fprintf(stderr, "usage: resident [-l] [-f] [-x id] [-d] [-R] program ...\n");
48 	exit(1);
49 }
50 
51 static int
52 list_residents(void)
53 {
54 	const char *mib = "vm.resident";
55 	struct xresident *buf;
56 	size_t res_count, res_total, i;
57 	int error;
58 
59 	/* get the number of resident binaries */
60 	error = sysctlbyname(mib, NULL, &res_count, NULL, 0);
61 	if (error != 0) {
62 		perror("sysctl: vm.resident");
63 		goto done;
64 	}
65 
66 	if (res_count == 0) {
67 		printf("no resident binaries to list\n");
68 		goto done;
69 	}
70 
71 	/* allocate memory for the list of binaries */
72 	res_total = sizeof(*buf) * res_count;
73 	if ((buf = malloc(res_total)) != NULL) {
74 		/* retrieve entries via sysctl */
75 		error = sysctlbyname(mib, buf, &res_total, NULL, 0);
76 		if (error != 0) {
77 			perror("sysctl: vm.resident");
78 			goto done;
79 		}
80 	} else {
81 		perror("malloc");
82 		goto done;
83 	}
84 
85 	/* print the list of retrieved resident binary */
86 	printf("%-4s\t%-15s\t%-12s\t%-30s\n","Id", "Size", "Address", "Executable");
87 	for (i = 0; i < res_count; ++i) {
88 		printf("%-4d\t%-15jd\t0x%-12x\t%-30s\n",
89 			buf[i].res_id,
90 			(intmax_t)buf[i].res_stat.st_size,
91 			(int)buf[i].res_entry_addr,
92 			buf[i].res_file);
93 	}
94 
95 	/* free back the memory */
96 	free(buf);
97 
98 done:
99 	return error;
100 }
101 
102 int
103 main(int argc, char *argv[])
104 {
105 	int	rval;
106 	int	c;
107 	int	doreg = 1;
108 	int	force = 0;
109 
110 	while ((c = getopt(argc, argv, "Rdflx:")) != -1) {
111 		switch (c) {
112 		case 'f':
113 			force = 1;
114 			break;
115 		case 'l':
116 			rval = list_residents();
117 			if (rval < 0)
118 				exit(EXIT_FAILURE);
119 			else
120 				exit(EXIT_SUCCESS);
121 		case 'd':
122 			doreg = 0;
123 			break;
124 		case 'x':
125 		case 'R':
126 			if (c == 'R')
127 			    c = exec_sys_unregister(-2);
128 			else
129 			    c = exec_sys_unregister(strtol(optarg, NULL, 0));
130 			if (c < 0)
131 			    printf("unregister: %s\n", strerror(errno));
132 			else
133 			    printf("unregister: success\n");
134 			exit(0);
135 		default:
136 			usage();
137 			/*NOTREACHED*/
138 		}
139 	}
140 	argc -= optind;
141 	argv += optind;
142 
143 	if (argc <= 0) {
144 		usage();
145 		/*NOTREACHED*/
146 	}
147 
148 	/* ld-elf.so magic */
149 	if (doreg) {
150 	    if (setenv("LD_RESIDENT_REGISTER_NOW", "yes", 1) == -1)
151 			err(1, "setenv failed");
152 	} else {
153 	    if (setenv("LD_RESIDENT_UNREGISTER_NOW", "yes", 1) == -1)
154 			err(1, "setenv failed");
155 	}
156 
157 	rval = 0;
158 	for ( ;  argc > 0;  argc--, argv++) {
159 		int	fd;
160 		union {
161 			struct exec aout;
162 			Elf_Ehdr elf;
163 		} hdr;
164 		int	n;
165 		int	status;
166 		int	file_ok;
167 		int	is_shlib;
168 
169 		if (force)
170 			goto force_target;
171 
172 		if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
173 			warn("%s", *argv);
174 			rval |= 1;
175 			continue;
176 		}
177 		if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
178 			warn("%s: can't read program header", *argv);
179 			close(fd);
180 			rval |= 1;
181 			continue;
182 		}
183 
184 		file_ok = 1;
185 		is_shlib = 0;
186 		if ((size_t)n >= sizeof hdr.aout && !N_BADMAG(hdr.aout)) {
187 			/* a.out file */
188 			if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC
189 #if 1 /* Compatibility */
190 			    || hdr.aout.a_entry < __LDPGSZ
191 #endif
192 				) {
193 				warnx("%s: not a dynamic executable", *argv);
194 				file_ok = 0;
195 			}
196 		} else if ((size_t)n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
197 			Elf_Ehdr ehdr;
198 			Elf_Phdr phdr;
199 			int dynamic = 0, i;
200 
201 			if (lseek(fd, 0, SEEK_SET) == -1 ||
202 			    read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
203 			    lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
204 			   ) {
205 				warnx("%s: can't read program header", *argv);
206 				file_ok = 0;
207 			} else {
208 				for (i = 0; i < ehdr.e_phnum; i++) {
209 					if (read(fd, &phdr, ehdr.e_phentsize)
210 					   != sizeof phdr) {
211 						warnx("%s: can't read program header",
212 						    *argv);
213 						file_ok = 0;
214 						break;
215 					}
216 					if (phdr.p_type == PT_DYNAMIC)
217 						dynamic = 1;
218 				}
219 			}
220 			if (!dynamic) {
221 				warnx("%s: not a dynamic executable", *argv);
222 				file_ok = 0;
223 			} else if (hdr.elf.e_type == ET_DYN) {
224 				if (hdr.elf.e_ident[EI_OSABI] & ELFOSABI_FREEBSD) {
225 					is_shlib = 1;
226 				} else {
227 					warnx("%s: not a FreeBSD ELF shared "
228 					      "object", *argv);
229 					file_ok = 0;
230 				}
231 			}
232 		} else {
233 			warnx("%s: not a dynamic executable", *argv);
234 			file_ok = 0;
235 		}
236 		close(fd);
237 		if (!file_ok) {
238 			rval |= 1;
239 			continue;
240 		}
241 
242 		if (is_shlib) {
243 			rval |= 1;
244 			warnx("%s: resident not supported on shared libraries.", *argv);
245 			continue;
246 		}
247 
248 force_target:
249 		fflush(stdout);
250 
251 		switch (fork()) {
252 		case -1:
253 			err(1, "fork");
254 			break;
255 		default:
256 			if (wait(&status) <= 0) {
257 				warn("wait");
258 				rval |= 1;
259 			} else if (WIFSIGNALED(status)) {
260 				fprintf(stderr, "%s: signal %d\n",
261 						*argv, WTERMSIG(status));
262 				rval |= 1;
263 			} else if (WIFEXITED(status) && WEXITSTATUS(status)) {
264 				switch(WEXITSTATUS(status)) {
265 				case ENOENT:
266 				    fprintf(stderr, "%s: entry not found\n",
267 					*argv);
268 				    break;
269 				case EEXIST:
270 				    fprintf(stderr, "%s: binary already resident\n",
271 					*argv);
272 				    break;
273 				default:
274 				    fprintf(stderr, "%s: exit status %s\n",
275 						*argv, strerror(WEXITSTATUS(status)));
276 				}
277 				rval |= 1;
278 			} else {
279 			}
280 			break;
281 		case 0:
282 			execl(*argv, *argv, NULL);
283 			warn("%s", *argv);
284 			_exit(1);
285 		}
286 	}
287 
288 	return rval;
289 }
290