1 /*- 2 * Copyright 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. Surprisingly 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/ptrace.h> 42 43 #include <err.h> 44 #include <signal.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <time.h> 48 #include <unistd.h> 49 50 #include "truss.h" 51 #include "extern.h" 52 #include "syscall.h" 53 54 static void 55 usage(void) 56 { 57 fprintf(stderr, "%s\n%s\n", 58 "usage: truss [-cfaedDS] [-o file] [-s strsize] -p pid", 59 " truss [-cfaedDS] [-o file] [-s strsize] command [args]"); 60 exit(1); 61 } 62 63 char * 64 strsig(int sig) 65 { 66 static char tmp[64]; 67 68 if (sig > 0 && sig < NSIG) { 69 snprintf(tmp, sizeof(tmp), "SIG%s", sys_signame[sig]); 70 return (tmp); 71 } 72 return (NULL); 73 } 74 75 int 76 main(int ac, char **av) 77 { 78 struct sigaction sa; 79 struct trussinfo *trussinfo; 80 char *fname; 81 char **command; 82 pid_t pid; 83 int c; 84 85 fname = NULL; 86 87 /* Initialize the trussinfo struct */ 88 trussinfo = (struct trussinfo *)calloc(1, sizeof(struct trussinfo)); 89 if (trussinfo == NULL) 90 errx(1, "calloc() failed"); 91 92 pid = 0; 93 trussinfo->outfile = stderr; 94 trussinfo->strsize = 32; 95 trussinfo->curthread = NULL; 96 LIST_INIT(&trussinfo->proclist); 97 while ((c = getopt(ac, av, "p:o:facedDs:S")) != -1) { 98 switch (c) { 99 case 'p': /* specified pid */ 100 pid = atoi(optarg); 101 /* make sure i don't trace me */ 102 if (pid == getpid()) { 103 errx(2, "attempt to grab self."); 104 } 105 break; 106 case 'f': /* Follow fork()'s */ 107 trussinfo->flags |= FOLLOWFORKS; 108 break; 109 case 'a': /* Print execve() argument strings. */ 110 trussinfo->flags |= EXECVEARGS; 111 break; 112 case 'c': /* Count number of system calls and time. */ 113 trussinfo->flags |= COUNTONLY; 114 break; 115 case 'e': /* Print execve() environment strings. */ 116 trussinfo->flags |= EXECVEENVS; 117 break; 118 case 'd': /* Absolute timestamps */ 119 trussinfo->flags |= ABSOLUTETIMESTAMPS; 120 break; 121 case 'D': /* Relative timestamps */ 122 trussinfo->flags |= RELATIVETIMESTAMPS; 123 break; 124 case 'o': /* Specified output file */ 125 fname = optarg; 126 break; 127 case 's': /* Specified string size */ 128 trussinfo->strsize = atoi(optarg); 129 break; 130 case 'S': /* Don't trace signals */ 131 trussinfo->flags |= NOSIGS; 132 break; 133 default: 134 usage(); 135 } 136 } 137 138 ac -= optind; av += optind; 139 if ((pid == 0 && ac == 0) || 140 (pid != 0 && ac != 0)) 141 usage(); 142 143 if (fname != NULL) { /* Use output file */ 144 /* 145 * Set close-on-exec ('e'), so that the output file is not 146 * shared with the traced process. 147 */ 148 if ((trussinfo->outfile = fopen(fname, "we")) == NULL) 149 err(1, "cannot open %s", fname); 150 } 151 152 /* 153 * If truss starts the process itself, it will ignore some signals -- 154 * they should be passed off to the process, which may or may not 155 * exit. If, however, we are examining an already-running process, 156 * then we restore the event mask on these same signals. 157 */ 158 if (pid == 0) { 159 /* Start a command ourselves */ 160 command = av; 161 setup_and_wait(trussinfo, command); 162 signal(SIGINT, SIG_IGN); 163 signal(SIGTERM, SIG_IGN); 164 signal(SIGQUIT, SIG_IGN); 165 } else { 166 sa.sa_handler = restore_proc; 167 sa.sa_flags = 0; 168 sigemptyset(&sa.sa_mask); 169 sigaction(SIGINT, &sa, NULL); 170 sigaction(SIGQUIT, &sa, NULL); 171 sigaction(SIGTERM, &sa, NULL); 172 start_tracing(trussinfo, pid); 173 } 174 175 /* 176 * At this point, if we started the process, it is stopped waiting to 177 * be woken up, either in exit() or in execve(). 178 */ 179 if (LIST_FIRST(&trussinfo->proclist)->abi == NULL) { 180 /* 181 * If we are not able to handle this ABI, detach from the 182 * process and exit. If we just created a new process to 183 * run a command, kill the new process rather than letting 184 * it run untraced. 185 */ 186 if (pid == 0) 187 kill(LIST_FIRST(&trussinfo->proclist)->pid, SIGKILL); 188 ptrace(PT_DETACH, LIST_FIRST(&trussinfo->proclist)->pid, NULL, 189 0); 190 return (1); 191 } 192 ptrace(PT_SYSCALL, LIST_FIRST(&trussinfo->proclist)->pid, (caddr_t)1, 193 0); 194 195 /* 196 * At this point, it's a simple loop, waiting for the process to 197 * stop, finding out why, printing out why, and then continuing it. 198 * All of the grunt work is done in the support routines. 199 */ 200 clock_gettime(CLOCK_REALTIME, &trussinfo->start_time); 201 202 eventloop(trussinfo); 203 204 if (trussinfo->flags & COUNTONLY) 205 print_summary(trussinfo); 206 207 fflush(trussinfo->outfile); 208 209 return (0); 210 } 211