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 */ 33 34 /* 35 * The main module for truss. Suprisingly simple, but, then, the other 36 * files handle the bulk of the work. And, of course, the kernel has to 37 * do a lot of the work :). 38 */ 39 40 #include <sys/param.h> 41 #include <sys/ioctl.h> 42 #include <sys/pioctl.h> 43 #include <sys/ucred.h> 44 #include <sys/mount.h> 45 46 #include <err.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <signal.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 55 #include "truss.h" 56 #include "extern.h" 57 58 /* 59 * These should really be parameterized -- I don't like having globals, 60 * but this is the easiest way, right now, to deal with them. 61 */ 62 63 int Procfd; 64 65 static void 66 usage(void) 67 { 68 fprintf(stderr, "%s\n%s\n", 69 "usage: truss [-S] [-o file] -p pid", 70 " truss [-S] [-o file] command [args]"); 71 exit(1); 72 } 73 74 struct ex_types { 75 const char *type; 76 void (*enter_syscall)(struct trussinfo *, int); 77 int (*exit_syscall)(struct trussinfo *, int); 78 } ex_types[] = { 79 #ifdef __x86_64__ 80 { "DragonFly ELF64", x86_64_syscall_entry, x86_64_syscall_exit }, 81 { "FreeBSD ELF64", x86_64_syscall_entry, x86_64_syscall_exit }, 82 #endif 83 { 0, 0, 0 }, 84 }; 85 86 /* 87 * Set the execution type. This is called after every exec, and when 88 * a process is first monitored. The procfs pseudo-file "etype" has 89 * the execution module type -- see /proc/curproc/etype for an example. 90 */ 91 92 static struct ex_types * 93 set_etype(struct trussinfo *trussinfo) { 94 struct ex_types *funcs; 95 char *etype; 96 char progt[32]; 97 int fd; 98 99 asprintf(&etype, "%s/%d/etype", procfs_path, trussinfo->pid); 100 if (etype == NULL) 101 err(1, "Out of memory"); 102 if ((fd = open(etype, O_RDONLY)) == -1) { 103 strcpy(progt, "FreeBSD a.out"); 104 } else { 105 int len = read(fd, progt, sizeof(progt)); 106 progt[len-1] = '\0'; 107 close(fd); 108 } 109 free(etype); 110 111 for (funcs = ex_types; funcs->type; funcs++) 112 if (!strcmp(funcs->type, progt)) 113 break; 114 115 if (funcs->type == NULL) { 116 funcs = &ex_types[0]; 117 warn("Execution type %s is not supported -- using %s\n", 118 progt, funcs->type); 119 } 120 return funcs; 121 } 122 123 int 124 main(int ac, char **av) { 125 int c, i, mntsize; 126 char **command; 127 struct procfs_status pfs; 128 struct ex_types *funcs; 129 struct statfs *mntbuf; 130 int in_exec = 0; 131 char *fname = NULL; 132 int sigexit = 0; 133 struct trussinfo *trussinfo; 134 135 /* Initialize the trussinfo struct */ 136 trussinfo = (struct trussinfo *)malloc(sizeof(struct trussinfo)); 137 if (trussinfo == NULL) 138 errx(1, "malloc() failed"); 139 bzero(trussinfo, sizeof(struct trussinfo)); 140 trussinfo->outfile = stderr; 141 142 /* Check where procfs is mounted if it is mounted */ 143 if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0) 144 err(1, "getmntinfo"); 145 for (i = 0; i < mntsize; i++) { 146 if (strcasecmp(mntbuf[i].f_mntfromname, "procfs") == 0) { 147 strlcpy(procfs_path, mntbuf[i].f_mntonname, sizeof(procfs_path)); 148 have_procfs = 1; 149 break; 150 } 151 } 152 if (!have_procfs) { 153 errno = 2; 154 err(1, "You must have a mounted procfs to use truss"); 155 } 156 157 while ((c = getopt(ac, av, "p:o:S")) != -1) { 158 switch (c) { 159 case 'p': /* specified pid */ 160 trussinfo->pid = atoi(optarg); 161 if (trussinfo->pid == getpid()) { 162 /* make sure truss doesn't trace itself */ 163 fprintf(stderr, "truss: attempt to self trace: %d\n", trussinfo->pid); 164 exit(2); 165 } 166 break; 167 case 'o': /* Specified output file */ 168 fname = optarg; 169 break; 170 case 'S': /* Don't trace signals */ 171 trussinfo->flags |= NOSIGS; 172 break; 173 default: 174 usage(); 175 } 176 } 177 178 ac -= optind; av += optind; 179 if ((trussinfo->pid == 0 && ac == 0) || (trussinfo->pid != 0 && ac != 0)) 180 usage(); 181 182 if (fname != NULL) { /* Use output file */ 183 if ((trussinfo->outfile = fopen(fname, "w")) == NULL) 184 errx(1, "cannot open %s", fname); 185 } 186 187 /* 188 * If truss starts the process itself, it will ignore some signals -- 189 * they should be passed off to the process, which may or may not 190 * exit. If, however, we are examining an already-running process, 191 * then we restore the event mask on these same signals. 192 */ 193 194 if (trussinfo->pid == 0) { /* Start a command ourselves */ 195 command = av; 196 trussinfo->pid = setup_and_wait(command); 197 signal(SIGINT, SIG_IGN); 198 signal(SIGTERM, SIG_IGN); 199 signal(SIGQUIT, SIG_IGN); 200 } else { 201 signal(SIGINT, restore_proc); 202 signal(SIGTERM, restore_proc); 203 signal(SIGQUIT, restore_proc); 204 } 205 206 207 /* 208 * At this point, if we started the process, it is stopped waiting to 209 * be woken up, either in exit() or in execve(). 210 */ 211 212 Procfd = start_tracing( 213 trussinfo->pid, S_EXEC | S_SCE | S_SCX | S_CORE | S_EXIT | 214 ((trussinfo->flags & NOSIGS) ? 0 : S_SIG)); 215 if (Procfd == -1) 216 return 0; 217 218 pfs.why = 0; 219 220 funcs = set_etype(trussinfo); 221 /* 222 * At this point, it's a simple loop, waiting for the process to 223 * stop, finding out why, printing out why, and then continuing it. 224 * All of the grunt work is done in the support routines. 225 */ 226 227 do { 228 int val = 0; 229 230 if (ioctl(Procfd, PIOCWAIT, &pfs) == -1) 231 warn("PIOCWAIT top of loop"); 232 else { 233 switch(i = pfs.why) { 234 case S_SCE: 235 funcs->enter_syscall(trussinfo, pfs.val); 236 break; 237 case S_SCX: 238 /* 239 * This is so we don't get two messages for an exec -- one 240 * for the S_EXEC, and one for the syscall exit. It also, 241 * conveniently, ensures that the first message printed out 242 * isn't the return-from-syscall used to create the process. 243 */ 244 245 if (in_exec) { 246 in_exec = 0; 247 break; 248 } 249 funcs->exit_syscall(trussinfo, pfs.val); 250 break; 251 case S_SIG: 252 fprintf(trussinfo->outfile, "SIGNAL %lu\n", pfs.val); 253 sigexit = pfs.val; 254 break; 255 case S_EXIT: 256 fprintf (trussinfo->outfile, "process exit, rval = %lu\n", pfs.val); 257 break; 258 case S_EXEC: 259 funcs = set_etype(trussinfo); 260 in_exec = 1; 261 break; 262 default: 263 fprintf (trussinfo->outfile, "Process stopped because of: %d\n", i); 264 break; 265 } 266 } 267 if (ioctl(Procfd, PIOCCONT, val) == -1) { 268 if (kill(trussinfo->pid, 0) == -1 && errno == ESRCH) 269 break; 270 else 271 warn("PIOCCONT"); 272 } 273 } while (pfs.why != S_EXIT); 274 fflush(trussinfo->outfile); 275 if (sigexit) { 276 if (sigexit == SIGQUIT) 277 exit(sigexit); 278 (void) signal(sigexit, SIG_DFL); 279 (void) kill(getpid(), sigexit); 280 } 281 return 0; 282 } 283