| 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 | * $DragonFly: src/usr.bin/truss/main.c,v 1.5 2005/05/28 00:22:04 swildner Exp $ |
| 33 | */ |
| 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/ucred.h> |
| 45 | #include <sys/mount.h> |
| 46 | |
| 47 | #include <err.h> |
| 48 | #include <errno.h> |
| 49 | #include <fcntl.h> |
| 50 | #include <signal.h> |
| 51 | #include <stdio.h> |
| 52 | #include <stdlib.h> |
| 53 | #include <string.h> |
| 54 | #include <unistd.h> |
| 55 | |
| 56 | #include "truss.h" |
| 57 | #include "extern.h" |
| 58 | |
| 59 | /* |
| 60 | * These should really be parameterized -- I don't like having globals, |
| 61 | * but this is the easiest way, right now, to deal with them. |
| 62 | */ |
| 63 | |
| 64 | int Procfd; |
| 65 | |
| 66 | static inline void |
| 67 | usage(void) |
| 68 | { |
| 69 | fprintf(stderr, "%s\n%s\n", |
| 70 | "usage: truss [-S] [-o file] -p pid", |
| 71 | " truss [-S] [-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 __i386__ |
| 85 | { "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit }, |
| 86 | { "FreeBSD ELF32", i386_syscall_entry, i386_syscall_exit }, |
| 87 | { "Linux ELF32", i386_linux_syscall_entry, i386_linux_syscall_exit }, |
| 88 | #endif |
| 89 | #ifdef __x86_64__ |
| 90 | { "FreeBSD ELF64", x86_64_syscall_entry, x86_64_syscall_exit }, |
| 91 | #endif |
| 92 | { 0, 0, 0 }, |
| 93 | }; |
| 94 | |
| 95 | /* |
| 96 | * Set the execution type. This is called after every exec, and when |
| 97 | * a process is first monitored. The procfs pseudo-file "etype" has |
| 98 | * the execution module type -- see /proc/curproc/etype for an example. |
| 99 | */ |
| 100 | |
| 101 | static struct ex_types * |
| 102 | set_etype(struct trussinfo *trussinfo) { |
| 103 | struct ex_types *funcs; |
| 104 | char *etype; |
| 105 | char progt[32]; |
| 106 | int fd; |
| 107 | |
| 108 | asprintf(&etype, "%s/%d/etype", procfs_path, trussinfo->pid); |
| 109 | if (etype == NULL) |
| 110 | err(1, "Out of memory"); |
| 111 | if ((fd = open(etype, O_RDONLY)) == -1) { |
| 112 | strcpy(progt, "FreeBSD a.out"); |
| 113 | } else { |
| 114 | int len = read(fd, progt, sizeof(progt)); |
| 115 | progt[len-1] = '\0'; |
| 116 | close(fd); |
| 117 | } |
| 118 | free(etype); |
| 119 | |
| 120 | for (funcs = ex_types; funcs->type; funcs++) |
| 121 | if (!strcmp(funcs->type, progt)) |
| 122 | break; |
| 123 | |
| 124 | if (funcs->type == NULL) { |
| 125 | funcs = &ex_types[0]; |
| 126 | warn("Execution type %s is not supported -- using %s\n", |
| 127 | progt, funcs->type); |
| 128 | } |
| 129 | return funcs; |
| 130 | } |
| 131 | |
| 132 | int |
| 133 | main(int ac, char **av) { |
| 134 | int c, i, mntsize; |
| 135 | char **command; |
| 136 | struct procfs_status pfs; |
| 137 | struct ex_types *funcs; |
| 138 | struct statfs *mntbuf; |
| 139 | int in_exec = 0; |
| 140 | char *fname = NULL; |
| 141 | int sigexit = 0; |
| 142 | struct trussinfo *trussinfo; |
| 143 | |
| 144 | /* Initialize the trussinfo struct */ |
| 145 | trussinfo = (struct trussinfo *)malloc(sizeof(struct trussinfo)); |
| 146 | if (trussinfo == NULL) |
| 147 | errx(1, "malloc() failed"); |
| 148 | bzero(trussinfo, sizeof(struct trussinfo)); |
| 149 | trussinfo->outfile = stderr; |
| 150 | |
| 151 | /* Check where procfs is mounted if it is mounted */ |
| 152 | if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0) |
| 153 | err(1, "getmntinfo"); |
| 154 | for (i = 0; i < mntsize; i++) { |
| 155 | if (strcasecmp(mntbuf[i].f_mntfromname, "procfs") == 0) { |
| 156 | strlcpy(procfs_path, mntbuf[i].f_mntonname, sizeof(procfs_path)); |
| 157 | have_procfs = 1; |
| 158 | break; |
| 159 | } |
| 160 | } |
| 161 | if (!have_procfs) { |
| 162 | errno = 2; |
| 163 | err(1, "You must have a mounted procfs to use truss"); |
| 164 | } |
| 165 | |
| 166 | while ((c = getopt(ac, av, "p:o:S")) != -1) { |
| 167 | switch (c) { |
| 168 | case 'p': /* specified pid */ |
| 169 | trussinfo->pid = atoi(optarg); |
| 170 | if (trussinfo->pid == getpid()) { |
| 171 | /* make sure truss doesn't trace itself */ |
| 172 | fprintf(stderr, "truss: attempt to self trace: %d\n", trussinfo->pid); |
| 173 | exit(2); |
| 174 | } |
| 175 | break; |
| 176 | case 'o': /* Specified output file */ |
| 177 | fname = optarg; |
| 178 | break; |
| 179 | case 'S': /* Don't trace signals */ |
| 180 | trussinfo->flags |= NOSIGS; |
| 181 | break; |
| 182 | default: |
| 183 | usage(); |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | ac -= optind; av += optind; |
| 188 | if ((trussinfo->pid == 0 && ac == 0) || (trussinfo->pid != 0 && ac != 0)) |
| 189 | usage(); |
| 190 | |
| 191 | if (fname != NULL) { /* Use output file */ |
| 192 | if ((trussinfo->outfile = fopen(fname, "w")) == NULL) |
| 193 | errx(1, "cannot open %s", fname); |
| 194 | } |
| 195 | |
| 196 | /* |
| 197 | * If truss starts the process itself, it will ignore some signals -- |
| 198 | * they should be passed off to the process, which may or may not |
| 199 | * exit. If, however, we are examining an already-running process, |
| 200 | * then we restore the event mask on these same signals. |
| 201 | */ |
| 202 | |
| 203 | if (trussinfo->pid == 0) { /* Start a command ourselves */ |
| 204 | command = av; |
| 205 | trussinfo->pid = setup_and_wait(command); |
| 206 | signal(SIGINT, SIG_IGN); |
| 207 | signal(SIGTERM, SIG_IGN); |
| 208 | signal(SIGQUIT, SIG_IGN); |
| 209 | } else { |
| 210 | signal(SIGINT, restore_proc); |
| 211 | signal(SIGTERM, restore_proc); |
| 212 | signal(SIGQUIT, restore_proc); |
| 213 | } |
| 214 | |
| 215 | |
| 216 | /* |
| 217 | * At this point, if we started the process, it is stopped waiting to |
| 218 | * be woken up, either in exit() or in execve(). |
| 219 | */ |
| 220 | |
| 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 | if (Procfd == -1) |
| 225 | return 0; |
| 226 | |
| 227 | pfs.why = 0; |
| 228 | |
| 229 | funcs = set_etype(trussinfo); |
| 230 | /* |
| 231 | * At this point, it's a simple loop, waiting for the process to |
| 232 | * stop, finding out why, printing out why, and then continuing it. |
| 233 | * All of the grunt work is done in the support routines. |
| 234 | */ |
| 235 | |
| 236 | do { |
| 237 | int val = 0; |
| 238 | |
| 239 | if (ioctl(Procfd, PIOCWAIT, &pfs) == -1) |
| 240 | warn("PIOCWAIT top of loop"); |
| 241 | else { |
| 242 | switch(i = pfs.why) { |
| 243 | case S_SCE: |
| 244 | funcs->enter_syscall(trussinfo, pfs.val); |
| 245 | break; |
| 246 | case S_SCX: |
| 247 | /* |
| 248 | * This is so we don't get two messages for an exec -- one |
| 249 | * for the S_EXEC, and one for the syscall exit. It also, |
| 250 | * conveniently, ensures that the first message printed out |
| 251 | * isn't the return-from-syscall used to create the process. |
| 252 | */ |
| 253 | |
| 254 | if (in_exec) { |
| 255 | in_exec = 0; |
| 256 | break; |
| 257 | } |
| 258 | funcs->exit_syscall(trussinfo, pfs.val); |
| 259 | break; |
| 260 | case S_SIG: |
| 261 | fprintf(trussinfo->outfile, "SIGNAL %lu\n", pfs.val); |
| 262 | sigexit = pfs.val; |
| 263 | break; |
| 264 | case S_EXIT: |
| 265 | fprintf (trussinfo->outfile, "process exit, rval = %lu\n", pfs.val); |
| 266 | break; |
| 267 | case S_EXEC: |
| 268 | funcs = set_etype(trussinfo); |
| 269 | in_exec = 1; |
| 270 | break; |
| 271 | default: |
| 272 | fprintf (trussinfo->outfile, "Process stopped because of: %d\n", i); |
| 273 | break; |
| 274 | } |
| 275 | } |
| 276 | if (ioctl(Procfd, PIOCCONT, val) == -1) { |
| 277 | if (kill(trussinfo->pid, 0) == -1 && errno == ESRCH) |
| 278 | break; |
| 279 | else |
| 280 | warn("PIOCCONT"); |
| 281 | } |
| 282 | } while (pfs.why != S_EXIT); |
| 283 | fflush(trussinfo->outfile); |
| 284 | if (sigexit) { |
| 285 | if (sigexit == SIGQUIT) |
| 286 | exit(sigexit); |
| 287 | (void) signal(sigexit, SIG_DFL); |
| 288 | (void) kill(getpid(), sigexit); |
| 289 | } |
| 290 | return 0; |
| 291 | } |