1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright 1997 Sean Eric Fagan 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by Sean Eric Fagan 17 * 4. Neither the name of the author may be used to endorse or promote 18 * products derived from this software without specific prior written 19 * permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * The main module for truss. Surprisingly 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/capsicum.h> 41 #include <sys/event.h> 42 #include <sys/ptrace.h> 43 44 #include <err.h> 45 #include <signal.h> 46 #include <stdbool.h> 47 #include <stdio.h> 48 #include <stdlib.h> 49 #include <sysdecode.h> 50 #include <time.h> 51 #include <unistd.h> 52 53 #include "truss.h" 54 #include "extern.h" 55 #include "syscall.h" 56 57 static __dead2 void 58 usage(void) 59 { 60 fprintf(stderr, "%s\n%s\n%s\n", 61 "usage: truss [-cfaedyDHS] [-o file] [-s strsize] [-t expr] -p pid", 62 " truss [-cfaedyDHS] [-o file] [-s strsize] [-t expr] " 63 "command [args]", 64 " truss -t"); 65 exit(1); 66 } 67 68 int 69 main(int ac, char **av) 70 { 71 struct sigaction sa; 72 struct trussinfo *trussinfo; 73 struct procinfo *np; 74 char *fname; 75 char **command; 76 const char *errstr; 77 pid_t pid; 78 int c; 79 80 fname = NULL; 81 82 /* Initialize the trussinfo struct */ 83 trussinfo = (struct trussinfo *)calloc(1, sizeof(struct trussinfo)); 84 if (trussinfo == NULL) 85 errx(1, "calloc() failed"); 86 87 pid = 0; 88 trussinfo->outfile = stderr; 89 trussinfo->strsize = 32; 90 trussinfo->curthread = NULL; 91 LIST_INIT(&trussinfo->proclist); 92 trussinfo->cap_mode = true; 93 94 /* 95 * The leading ':' asks getopt() to report a missing option 96 * argument as ':' rather than '?' so that a bare -t, which lists 97 * the system call groups, can be told from a malformed option. 98 * Diagnosing the other two cases then falls to us. 99 */ 100 while ((c = getopt(ac, av, ":p:o:facedyDs:t:SH")) != -1) { 101 switch (c) { 102 case 'p': /* specified pid */ 103 pid = atoi(optarg); 104 /* make sure i don't trace me */ 105 if (pid == getpid()) { 106 errx(2, "attempt to grab self."); 107 } 108 break; 109 case 'f': /* Follow fork()'s */ 110 trussinfo->flags |= FOLLOWFORKS; 111 break; 112 case 'a': /* Print execve() argument strings. */ 113 trussinfo->flags |= EXECVEARGS; 114 break; 115 case 'c': /* Count number of system calls and time. */ 116 trussinfo->flags |= (COUNTONLY | NOSIGS); 117 break; 118 case 'e': /* Print execve() environment strings. */ 119 trussinfo->flags |= EXECVEENVS; 120 break; 121 case 'd': /* Absolute timestamps */ 122 trussinfo->flags |= ABSOLUTETIMESTAMPS; 123 break; 124 case 'D': /* Relative timestamps */ 125 trussinfo->flags |= RELATIVETIMESTAMPS; 126 break; 127 case 'o': /* Specified output file */ 128 fname = optarg; 129 break; 130 case 's': /* Specified string size */ 131 trussinfo->strsize = (int)strtonum(optarg, 0, INT_MAX, 132 &errstr); 133 if (errstr) 134 errx(1, "maximum string size is %s: %s", errstr, optarg); 135 break; 136 case 't': /* Select the system calls to trace */ 137 add_syscall_filter(optarg); 138 break; 139 case 'y': 140 trussinfo->cap_mode = false; 141 break; 142 case 'S': /* Don't trace signals */ 143 trussinfo->flags |= NOSIGS; 144 break; 145 case 'H': 146 trussinfo->flags |= DISPLAYTIDS; 147 break; 148 case ':': 149 if (optopt == 't') { 150 /* A bare -t lists the system call groups. */ 151 list_syscall_groups(); 152 return (2); 153 } 154 warnx("option requires an argument -- %c", optopt); 155 usage(); 156 default: 157 warnx("illegal option -- %c", optopt); 158 usage(); 159 } 160 } 161 162 ac -= optind; av += optind; 163 if ((pid == 0 && ac == 0) || 164 (pid != 0 && ac != 0)) 165 usage(); 166 167 if (fname != NULL) { /* Use output file */ 168 /* 169 * Set close-on-exec ('e'), so that the output file is not 170 * shared with the traced process. 171 */ 172 if ((trussinfo->outfile = fopen(fname, "we")) == NULL) 173 err(1, "cannot open %s", fname); 174 } 175 176 if (trussinfo->cap_mode) { 177 trussinfo->pdkq = kqueue(); 178 if (trussinfo->pdkq == -1) 179 err(1, "kqueue"); 180 } 181 182 /* 183 * If truss starts the process itself, it will ignore some signals -- 184 * they should be passed off to the process, which may or may not 185 * exit. If, however, we are examining an already-running process, 186 * then we restore the event mask on these same signals. 187 */ 188 if (pid == 0) { 189 /* Start a command ourselves */ 190 command = av; 191 setup_and_wait(trussinfo, command); 192 signal(SIGINT, SIG_IGN); 193 signal(SIGTERM, SIG_IGN); 194 signal(SIGQUIT, SIG_IGN); 195 } else { 196 sa.sa_handler = restore_proc; 197 sa.sa_flags = 0; 198 sigemptyset(&sa.sa_mask); 199 sigaction(SIGINT, &sa, NULL); 200 sigaction(SIGQUIT, &sa, NULL); 201 sigaction(SIGTERM, &sa, NULL); 202 start_tracing(trussinfo, pid); 203 } 204 205 /* 206 * At this point, if we started the process, it is stopped waiting to 207 * be woken up, either in exit() or in execve(). 208 */ 209 np = LIST_FIRST(&trussinfo->proclist); 210 if (np->abi == NULL) { 211 /* 212 * If we are not able to handle this ABI, detach from the 213 * process and exit. If we just created a new process to 214 * run a command, kill the new process rather than letting 215 * it run untraced. 216 */ 217 if (pid == 0) 218 truss_kill(trussinfo, np, SIGKILL); 219 truss_ptrace(trussinfo, PT_DETACH, np, NULL, 0); 220 return (1); 221 } 222 truss_ptrace(trussinfo, PT_SYSCALL, np, (caddr_t)1, 0); 223 224 /* 225 * At this point, it's a simple loop, waiting for the process to 226 * stop, finding out why, printing out why, and then continuing it. 227 * All of the grunt work is done in the support routines. 228 */ 229 clock_gettime(CLOCK_REALTIME, &trussinfo->start_time); 230 231 eventloop(trussinfo); 232 233 if (trussinfo->flags & COUNTONLY) 234 print_summary(trussinfo); 235 236 fflush(trussinfo->outfile); 237 238 return (0); 239 } 240