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 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 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/time.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 <time.h> 54 #include <unistd.h> 55 56 #include "truss.h" 57 #include "extern.h" 58 59 /* 60 * It's difficult to parameterize this because it must be 61 * accessible in a signal handler. 62 */ 63 64 int Procfd; 65 66 static __inline void 67 usage(void) 68 { 69 fprintf(stderr, "%s\n%s\n", 70 "usage: truss [-faedDS] [-o file] -p pid", 71 " truss [-faedDS] [-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 __alpha__ 85 { "FreeBSD ELF", alpha_syscall_entry, alpha_syscall_exit }, 86 #endif 87 #ifdef __i386__ 88 { "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit }, 89 { "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit }, 90 { "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit }, 91 { "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit }, 92 #endif 93 #ifdef __ia64__ 94 { "FreeBSD ELF64", ia64_syscall_entry, ia64_syscall_exit }, 95 #endif 96 #ifdef __sparc64__ 97 { "FreeBSD ELF64", sparc64_syscall_entry, sparc64_syscall_exit }, 98 #endif 99 { 0, 0, 0 }, 100 }; 101 102 /* 103 * Set the execution type. This is called after every exec, and when 104 * a process is first monitored. The procfs pseudo-file "etype" has 105 * the execution module type -- see /proc/curproc/etype for an example. 106 */ 107 108 static struct ex_types * 109 set_etype(struct trussinfo *trussinfo) { 110 struct ex_types *funcs; 111 char etype[24]; 112 char progt[32]; 113 int fd; 114 115 sprintf(etype, "/proc/%d/etype", trussinfo->pid); 116 if ((fd = open(etype, O_RDONLY)) == -1) { 117 strcpy(progt, "FreeBSD a.out"); 118 } else { 119 int len = read(fd, progt, sizeof(progt)); 120 progt[len-1] = '\0'; 121 close(fd); 122 } 123 124 for (funcs = ex_types; funcs->type; funcs++) 125 if (!strcmp(funcs->type, progt)) 126 break; 127 128 if (funcs->type == NULL) { 129 funcs = &ex_types[0]; 130 warn("execution type %s is not supported -- using %s", 131 progt, funcs->type); 132 } 133 return funcs; 134 } 135 136 int 137 main(int ac, char **av) { 138 int c; 139 int i; 140 char **command; 141 struct procfs_status pfs; 142 struct ex_types *funcs; 143 int in_exec = 0; 144 char *fname = NULL; 145 int sigexit = 0; 146 struct trussinfo *trussinfo; 147 148 /* Initialize the trussinfo struct */ 149 trussinfo = (struct trussinfo *)malloc(sizeof(struct trussinfo)); 150 if (trussinfo == NULL) 151 errx(1, "malloc() failed"); 152 bzero(trussinfo, sizeof(struct trussinfo)); 153 trussinfo->outfile = stderr; 154 155 while ((c = getopt(ac, av, "p:o:faedDS")) != -1) { 156 switch (c) { 157 case 'p': /* specified pid */ 158 trussinfo->pid = atoi(optarg); 159 break; 160 case 'f': /* Follow fork()'s */ 161 trussinfo->flags |= FOLLOWFORKS; 162 break; 163 case 'a': /* Print execve() argument strings. */ 164 trussinfo->flags |= EXECVEARGS; 165 break; 166 case 'e': /* Print execve() environment strings. */ 167 trussinfo->flags |= EXECVEENVS; 168 break; 169 case 'd': /* Absolute timestamps */ 170 trussinfo->flags |= ABSOLUTETIMESTAMPS; 171 break; 172 case 'D': /* Relative timestamps */ 173 trussinfo->flags |= RELATIVETIMESTAMPS; 174 break; 175 case 'o': /* Specified output file */ 176 fname = optarg; 177 break; 178 case 'S': /* Don't trace signals */ 179 trussinfo->flags |= NOSIGS; 180 break; 181 default: 182 usage(); 183 } 184 } 185 186 ac -= optind; av += optind; 187 if ((trussinfo->pid == 0 && ac == 0) || (trussinfo->pid != 0 && ac != 0)) 188 usage(); 189 190 if (fname != NULL) { /* Use output file */ 191 if ((trussinfo->outfile = fopen(fname, "w")) == NULL) 192 errx(1, "cannot open %s", fname); 193 } 194 195 /* 196 * If truss starts the process itself, it will ignore some signals -- 197 * they should be passed off to the process, which may or may not 198 * exit. If, however, we are examining an already-running process, 199 * then we restore the event mask on these same signals. 200 */ 201 202 if (trussinfo->pid == 0) { /* Start a command ourselves */ 203 command = av; 204 trussinfo->pid = setup_and_wait(command); 205 signal(SIGINT, SIG_IGN); 206 signal(SIGTERM, SIG_IGN); 207 signal(SIGQUIT, SIG_IGN); 208 } else { 209 signal(SIGINT, restore_proc); 210 signal(SIGTERM, restore_proc); 211 signal(SIGQUIT, restore_proc); 212 } 213 214 215 /* 216 * At this point, if we started the process, it is stopped waiting to 217 * be woken up, either in exit() or in execve(). 218 */ 219 220 START_TRACE: 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 ((trussinfo->flags & FOLLOWFORKS) ? PF_FORK : 0)); 225 if (Procfd == -1) 226 return 0; 227 228 pfs.why = 0; 229 230 funcs = set_etype(trussinfo); 231 /* 232 * At this point, it's a simple loop, waiting for the process to 233 * stop, finding out why, printing out why, and then continuing it. 234 * All of the grunt work is done in the support routines. 235 */ 236 237 clock_gettime(CLOCK_REALTIME, &trussinfo->start_time); 238 239 do { 240 int val = 0; 241 242 if (ioctl(Procfd, PIOCWAIT, &pfs) == -1) 243 warn("PIOCWAIT top of loop"); 244 else { 245 switch(i = pfs.why) { 246 case S_SCE: 247 funcs->enter_syscall(trussinfo, pfs.val); 248 clock_gettime(CLOCK_REALTIME, &trussinfo->before); 249 break; 250 case S_SCX: 251 clock_gettime(CLOCK_REALTIME, &trussinfo->after); 252 /* 253 * This is so we don't get two messages for an exec -- one 254 * for the S_EXEC, and one for the syscall exit. It also, 255 * conveniently, ensures that the first message printed out 256 * isn't the return-from-syscall used to create the process. 257 */ 258 259 if (in_exec) { 260 in_exec = 0; 261 break; 262 } 263 264 if (trussinfo->in_fork && (trussinfo->flags & FOLLOWFORKS)) { 265 int childpid; 266 267 trussinfo->in_fork = 0; 268 childpid = funcs->exit_syscall(trussinfo, pfs.val); 269 270 /* 271 * Fork a new copy of ourself to trace the child of the 272 * original traced process. 273 */ 274 if (fork() == 0) { 275 trussinfo->pid = childpid; 276 goto START_TRACE; 277 } 278 break; 279 } 280 funcs->exit_syscall(trussinfo, pfs.val); 281 break; 282 case S_SIG: 283 fprintf(trussinfo->outfile, "SIGNAL %lu\n", pfs.val); 284 sigexit = pfs.val; 285 break; 286 case S_EXIT: 287 fprintf (trussinfo->outfile, "process exit, rval = %lu\n", pfs.val); 288 break; 289 case S_EXEC: 290 funcs = set_etype(trussinfo); 291 in_exec = 1; 292 break; 293 default: 294 fprintf (trussinfo->outfile, "Process stopped because of: %d\n", i); 295 break; 296 } 297 } 298 if (ioctl(Procfd, PIOCCONT, val) == -1) { 299 if (kill(trussinfo->pid, 0) == -1 && errno == ESRCH) 300 break; 301 else 302 warn("PIOCCONT"); 303 } 304 } while (pfs.why != S_EXIT); 305 fflush(trussinfo->outfile); 306 if (sigexit) { 307 if (sigexit == SIGQUIT) 308 exit(sigexit); 309 (void) signal(sigexit, SIG_DFL); 310 (void) kill(getpid(), sigexit); 311 } 312 return 0; 313 } 314