1 /* 2 * Copryight 1997 Sean Eric Fagan 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. All advertising materials mentioning features or use of this software 13 * must display the following acknowledgement: 14 * This product includes software developed by Sean Eric Fagan 15 * 4. Neither the name of the author may be used to endorse or promote 16 * products derived from this software without specific prior written 17 * permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $FreeBSD: src/usr.bin/truss/main.c,v 1.15.2.3 2002/05/16 23:41:23 peter Exp $ 32 * $DragonFly: src/usr.bin/truss/main.c,v 1.5 2005/05/28 00:22:04 swildner Exp $ 33 */ 34 35 /* 36 * The main module for truss. Suprisingly simple, but, then, the other 37 * files handle the bulk of the work. And, of course, the kernel has to 38 * do a lot of the work :). 39 */ 40 41 #include <sys/param.h> 42 #include <sys/ioctl.h> 43 #include <sys/pioctl.h> 44 #include <sys/ucred.h> 45 #include <sys/mount.h> 46 47 #include <err.h> 48 #include <errno.h> 49 #include <fcntl.h> 50 #include <signal.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 56 #include "truss.h" 57 #include "extern.h" 58 59 /* 60 * These should really be parameterized -- I don't like having globals, 61 * but this is the easiest way, right now, to deal with them. 62 */ 63 64 int Procfd; 65 66 static inline void 67 usage(void) 68 { 69 fprintf(stderr, "%s\n%s\n", 70 "usage: truss [-S] [-o file] -p pid", 71 " truss [-S] [-o file] command [args]"); 72 exit(1); 73 } 74 75 /* 76 * WARNING! "FreeBSD a.out" must be first, or set_etype will not 77 * work correctly. 78 */ 79 struct ex_types { 80 const char *type; 81 void (*enter_syscall)(struct trussinfo *, int); 82 int (*exit_syscall)(struct trussinfo *, int); 83 } ex_types[] = { 84 #ifdef __i386__ 85 { "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit }, 86 { "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit }, 87 { "Linux ELF32", i386_linux_syscall_entry, i386_linux_syscall_exit }, 88 #endif 89 #ifdef __x86_64__ 90 { "FreeBSD ELF64", x86_64_syscall_entry, x86_64_syscall_exit }, 91 #endif 92 { 0, 0, 0 }, 93 }; 94 95 /* 96 * Set the execution type. This is called after every exec, and when 97 * a process is first monitored. The procfs pseudo-file "etype" has 98 * the execution module type -- see /proc/curproc/etype for an example. 99 */ 100 101 static struct ex_types * 102 set_etype(struct trussinfo *trussinfo) { 103 struct ex_types *funcs; 104 char *etype; 105 char progt[32]; 106 int fd; 107 108 asprintf(&etype, "%s/%d/etype", procfs_path, trussinfo->pid); 109 if (etype == NULL) 110 err(1, "Out of memory"); 111 if ((fd = open(etype, O_RDONLY)) == -1) { 112 strcpy(progt, "FreeBSD a.out"); 113 } else { 114 int len = read(fd, progt, sizeof(progt)); 115 progt[len-1] = '\0'; 116 close(fd); 117 } 118 free(etype); 119 120 for (funcs = ex_types; funcs->type; funcs++) 121 if (!strcmp(funcs->type, progt)) 122 break; 123 124 if (funcs->type == NULL) { 125 funcs = &ex_types[0]; 126 warn("Execution type %s is not supported -- using %s\n", 127 progt, funcs->type); 128 } 129 return funcs; 130 } 131 132 int 133 main(int ac, char **av) { 134 int c, i, mntsize; 135 char **command; 136 struct procfs_status pfs; 137 struct ex_types *funcs; 138 struct statfs *mntbuf; 139 int in_exec = 0; 140 char *fname = NULL; 141 int sigexit = 0; 142 struct trussinfo *trussinfo; 143 144 /* Initialize the trussinfo struct */ 145 trussinfo = (struct trussinfo *)malloc(sizeof(struct trussinfo)); 146 if (trussinfo == NULL) 147 errx(1, "malloc() failed"); 148 bzero(trussinfo, sizeof(struct trussinfo)); 149 trussinfo->outfile = stderr; 150 151 /* Check where procfs is mounted if it is mounted */ 152 if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0) 153 err(1, "getmntinfo"); 154 for (i = 0; i < mntsize; i++) { 155 if (strcasecmp(mntbuf[i].f_mntfromname, "procfs") == 0) { 156 strlcpy(procfs_path, mntbuf[i].f_mntonname, sizeof(procfs_path)); 157 have_procfs = 1; 158 break; 159 } 160 } 161 if (!have_procfs) { 162 errno = 2; 163 err(1, "You must have a mounted procfs to use truss"); 164 } 165 166 while ((c = getopt(ac, av, "p:o:S")) != -1) { 167 switch (c) { 168 case 'p': /* specified pid */ 169 trussinfo->pid = atoi(optarg); 170 if (trussinfo->pid == getpid()) { 171 /* make sure truss doesn't trace itself */ 172 fprintf(stderr, "truss: attempt to self trace: %d\n", trussinfo->pid); 173 exit(2); 174 } 175 break; 176 case 'o': /* Specified output file */ 177 fname = optarg; 178 break; 179 case 'S': /* Don't trace signals */ 180 trussinfo->flags |= NOSIGS; 181 break; 182 default: 183 usage(); 184 } 185 } 186 187 ac -= optind; av += optind; 188 if ((trussinfo->pid == 0 && ac == 0) || (trussinfo->pid != 0 && ac != 0)) 189 usage(); 190 191 if (fname != NULL) { /* Use output file */ 192 if ((trussinfo->outfile = fopen(fname, "w")) == NULL) 193 errx(1, "cannot open %s", fname); 194 } 195 196 /* 197 * If truss starts the process itself, it will ignore some signals -- 198 * they should be passed off to the process, which may or may not 199 * exit. If, however, we are examining an already-running process, 200 * then we restore the event mask on these same signals. 201 */ 202 203 if (trussinfo->pid == 0) { /* Start a command ourselves */ 204 command = av; 205 trussinfo->pid = setup_and_wait(command); 206 signal(SIGINT, SIG_IGN); 207 signal(SIGTERM, SIG_IGN); 208 signal(SIGQUIT, SIG_IGN); 209 } else { 210 signal(SIGINT, restore_proc); 211 signal(SIGTERM, restore_proc); 212 signal(SIGQUIT, restore_proc); 213 } 214 215 216 /* 217 * At this point, if we started the process, it is stopped waiting to 218 * be woken up, either in exit() or in execve(). 219 */ 220 221 Procfd = start_tracing( 222 trussinfo->pid, S_EXEC | S_SCE | S_SCX | S_CORE | S_EXIT | 223 ((trussinfo->flags & NOSIGS) ? 0 : S_SIG)); 224 if (Procfd == -1) 225 return 0; 226 227 pfs.why = 0; 228 229 funcs = set_etype(trussinfo); 230 /* 231 * At this point, it's a simple loop, waiting for the process to 232 * stop, finding out why, printing out why, and then continuing it. 233 * All of the grunt work is done in the support routines. 234 */ 235 236 do { 237 int val = 0; 238 239 if (ioctl(Procfd, PIOCWAIT, &pfs) == -1) 240 warn("PIOCWAIT top of loop"); 241 else { 242 switch(i = pfs.why) { 243 case S_SCE: 244 funcs->enter_syscall(trussinfo, pfs.val); 245 break; 246 case S_SCX: 247 /* 248 * This is so we don't get two messages for an exec -- one 249 * for the S_EXEC, and one for the syscall exit. It also, 250 * conveniently, ensures that the first message printed out 251 * isn't the return-from-syscall used to create the process. 252 */ 253 254 if (in_exec) { 255 in_exec = 0; 256 break; 257 } 258 funcs->exit_syscall(trussinfo, pfs.val); 259 break; 260 case S_SIG: 261 fprintf(trussinfo->outfile, "SIGNAL %lu\n", pfs.val); 262 sigexit = pfs.val; 263 break; 264 case S_EXIT: 265 fprintf (trussinfo->outfile, "process exit, rval = %lu\n", pfs.val); 266 break; 267 case S_EXEC: 268 funcs = set_etype(trussinfo); 269 in_exec = 1; 270 break; 271 default: 272 fprintf (trussinfo->outfile, "Process stopped because of: %d\n", i); 273 break; 274 } 275 } 276 if (ioctl(Procfd, PIOCCONT, val) == -1) { 277 if (kill(trussinfo->pid, 0) == -1 && errno == ESRCH) 278 break; 279 else 280 warn("PIOCCONT"); 281 } 282 } while (pfs.why != S_EXIT); 283 fflush(trussinfo->outfile); 284 if (sigexit) { 285 if (sigexit == SIGQUIT) 286 exit(sigexit); 287 (void) signal(sigexit, SIG_DFL); 288 (void) kill(getpid(), sigexit); 289 } 290 return 0; 291 } 292