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 inline 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 __i386__ 80 { "DragonFly ELF32", i386_syscall_entry, i386_syscall_exit }, 81 { "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit }, 82 { "Linux ELF32", i386_linux_syscall_entry, i386_linux_syscall_exit }, 83 #endif 84 #ifdef __x86_64__ 85 { "DragonFly ELF64", x86_64_syscall_entry, x86_64_syscall_exit }, 86 { "FreeBSD ELF64", x86_64_syscall_entry, x86_64_syscall_exit }, 87 #endif 88 { 0, 0, 0 }, 89 }; 90 91 /* 92 * Set the execution type. This is called after every exec, and when 93 * a process is first monitored. The procfs pseudo-file "etype" has 94 * the execution module type -- see /proc/curproc/etype for an example. 95 */ 96 97 static struct ex_types * 98 set_etype(struct trussinfo *trussinfo) { 99 struct ex_types *funcs; 100 char *etype; 101 char progt[32]; 102 int fd; 103 104 asprintf(&etype, "%s/%d/etype", procfs_path, trussinfo->pid); 105 if (etype == NULL) 106 err(1, "Out of memory"); 107 if ((fd = open(etype, O_RDONLY)) == -1) { 108 strcpy(progt, "FreeBSD a.out"); 109 } else { 110 int len = read(fd, progt, sizeof(progt)); 111 progt[len-1] = '\0'; 112 close(fd); 113 } 114 free(etype); 115 116 for (funcs = ex_types; funcs->type; funcs++) 117 if (!strcmp(funcs->type, progt)) 118 break; 119 120 if (funcs->type == NULL) { 121 funcs = &ex_types[0]; 122 warn("Execution type %s is not supported -- using %s\n", 123 progt, funcs->type); 124 } 125 return funcs; 126 } 127 128 int 129 main(int ac, char **av) { 130 int c, i, mntsize; 131 char **command; 132 struct procfs_status pfs; 133 struct ex_types *funcs; 134 struct statfs *mntbuf; 135 int in_exec = 0; 136 char *fname = NULL; 137 int sigexit = 0; 138 struct trussinfo *trussinfo; 139 140 /* Initialize the trussinfo struct */ 141 trussinfo = (struct trussinfo *)malloc(sizeof(struct trussinfo)); 142 if (trussinfo == NULL) 143 errx(1, "malloc() failed"); 144 bzero(trussinfo, sizeof(struct trussinfo)); 145 trussinfo->outfile = stderr; 146 147 /* Check where procfs is mounted if it is mounted */ 148 if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0) 149 err(1, "getmntinfo"); 150 for (i = 0; i < mntsize; i++) { 151 if (strcasecmp(mntbuf[i].f_mntfromname, "procfs") == 0) { 152 strlcpy(procfs_path, mntbuf[i].f_mntonname, sizeof(procfs_path)); 153 have_procfs = 1; 154 break; 155 } 156 } 157 if (!have_procfs) { 158 errno = 2; 159 err(1, "You must have a mounted procfs to use truss"); 160 } 161 162 while ((c = getopt(ac, av, "p:o:S")) != -1) { 163 switch (c) { 164 case 'p': /* specified pid */ 165 trussinfo->pid = atoi(optarg); 166 if (trussinfo->pid == getpid()) { 167 /* make sure truss doesn't trace itself */ 168 fprintf(stderr, "truss: attempt to self trace: %d\n", trussinfo->pid); 169 exit(2); 170 } 171 break; 172 case 'o': /* Specified output file */ 173 fname = optarg; 174 break; 175 case 'S': /* Don't trace signals */ 176 trussinfo->flags |= NOSIGS; 177 break; 178 default: 179 usage(); 180 } 181 } 182 183 ac -= optind; av += optind; 184 if ((trussinfo->pid == 0 && ac == 0) || (trussinfo->pid != 0 && ac != 0)) 185 usage(); 186 187 if (fname != NULL) { /* Use output file */ 188 if ((trussinfo->outfile = fopen(fname, "w")) == NULL) 189 errx(1, "cannot open %s", fname); 190 } 191 192 /* 193 * If truss starts the process itself, it will ignore some signals -- 194 * they should be passed off to the process, which may or may not 195 * exit. If, however, we are examining an already-running process, 196 * then we restore the event mask on these same signals. 197 */ 198 199 if (trussinfo->pid == 0) { /* Start a command ourselves */ 200 command = av; 201 trussinfo->pid = setup_and_wait(command); 202 signal(SIGINT, SIG_IGN); 203 signal(SIGTERM, SIG_IGN); 204 signal(SIGQUIT, SIG_IGN); 205 } else { 206 signal(SIGINT, restore_proc); 207 signal(SIGTERM, restore_proc); 208 signal(SIGQUIT, restore_proc); 209 } 210 211 212 /* 213 * At this point, if we started the process, it is stopped waiting to 214 * be woken up, either in exit() or in execve(). 215 */ 216 217 Procfd = start_tracing( 218 trussinfo->pid, S_EXEC | S_SCE | S_SCX | S_CORE | S_EXIT | 219 ((trussinfo->flags & NOSIGS) ? 0 : S_SIG)); 220 if (Procfd == -1) 221 return 0; 222 223 pfs.why = 0; 224 225 funcs = set_etype(trussinfo); 226 /* 227 * At this point, it's a simple loop, waiting for the process to 228 * stop, finding out why, printing out why, and then continuing it. 229 * All of the grunt work is done in the support routines. 230 */ 231 232 do { 233 int val = 0; 234 235 if (ioctl(Procfd, PIOCWAIT, &pfs) == -1) 236 warn("PIOCWAIT top of loop"); 237 else { 238 switch(i = pfs.why) { 239 case S_SCE: 240 funcs->enter_syscall(trussinfo, pfs.val); 241 break; 242 case S_SCX: 243 /* 244 * This is so we don't get two messages for an exec -- one 245 * for the S_EXEC, and one for the syscall exit. It also, 246 * conveniently, ensures that the first message printed out 247 * isn't the return-from-syscall used to create the process. 248 */ 249 250 if (in_exec) { 251 in_exec = 0; 252 break; 253 } 254 funcs->exit_syscall(trussinfo, pfs.val); 255 break; 256 case S_SIG: 257 fprintf(trussinfo->outfile, "SIGNAL %lu\n", pfs.val); 258 sigexit = pfs.val; 259 break; 260 case S_EXIT: 261 fprintf (trussinfo->outfile, "process exit, rval = %lu\n", pfs.val); 262 break; 263 case S_EXEC: 264 funcs = set_etype(trussinfo); 265 in_exec = 1; 266 break; 267 default: 268 fprintf (trussinfo->outfile, "Process stopped because of: %d\n", i); 269 break; 270 } 271 } 272 if (ioctl(Procfd, PIOCCONT, val) == -1) { 273 if (kill(trussinfo->pid, 0) == -1 && errno == ESRCH) 274 break; 275 else 276 warn("PIOCCONT"); 277 } 278 } while (pfs.why != S_EXIT); 279 fflush(trussinfo->outfile); 280 if (sigexit) { 281 if (sigexit == SIGQUIT) 282 exit(sigexit); 283 (void) signal(sigexit, SIG_DFL); 284 (void) kill(getpid(), sigexit); 285 } 286 return 0; 287 } 288