/* * Copryight 1997 Sean Eric Fagan * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Sean Eric Fagan * 4. Neither the name of the author may be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint static const char rcsid[] = "$FreeBSD$"; #endif /* not lint */ /* * The main module for truss. Suprisingly simple, but, then, the other * files handle the bulk of the work. And, of course, the kernel has to * do a lot of the work :). */ #include #include #include #include #include #include #include #include #include #include #include #include "extern.h" /* * These should really be parameterized -- I don't like having globals, * but this is the easiest way, right now, to deal with them. */ int pid = 0; int nosigs = 0; FILE *outfile; int Procfd; static inline void usage(void) { fprintf(stderr, "%s\n%s\n", "usage: truss [-S] [-o file] -p pid", " truss [-S] [-o file] command [args]"); exit(1); } /* * WARNING! "FreeBSD a.out" must be first, or set_etype will not * work correctly. */ struct ex_types { const char *type; void (*enter_syscall)(int, int); void (*exit_syscall)(int, int); } ex_types[] = { #ifdef __alpha__ { "FreeBSD ELF", alpha_syscall_entry, alpha_syscall_exit }, #endif #ifdef __i386__ { "FreeBSD a.out", i386_syscall_entry, i386_syscall_exit }, { "FreeBSD ELF", i386_syscall_entry, i386_syscall_exit }, { "Linux ELF", i386_linux_syscall_entry, i386_linux_syscall_exit }, #endif { 0, 0, 0 }, }; /* * Set the execution type. This is called after every exec, and when * a process is first monitored. The procfs pseudo-file "etype" has * the execution module type -- see /proc/curproc/etype for an example. */ static struct ex_types * set_etype(void) { struct ex_types *funcs; char etype[24]; char progt[32]; int fd; sprintf(etype, "/proc/%d/etype", pid); if ((fd = open(etype, O_RDONLY)) == -1) { strcpy(progt, "FreeBSD a.out"); } else { int len = read(fd, progt, sizeof(progt)); progt[len-1] = '\0'; close(fd); } for (funcs = ex_types; funcs->type; funcs++) if (!strcmp(funcs->type, progt)) break; if (funcs->type == NULL) { funcs = &ex_types[0]; warn("Execution type %s is not supported -- using %s\n", progt, funcs->type); } return funcs; } int main(int ac, char **av) { int c; int i; char **command; struct procfs_status pfs; struct ex_types *funcs; int in_exec = 0; char *fname = NULL; int sigexit = 0; outfile = stdout; while ((c = getopt(ac, av, "p:o:S")) != -1) { switch (c) { case 'p': /* specified pid */ pid = atoi(optarg); break; case 'o': /* Specified output file */ fname = optarg; break; case 'S': /* Don't trace signals */ nosigs = 1; break; default: usage(); } } ac -= optind; av += optind; if ((pid == 0 && ac == 0) || (pid != 0 && ac != 0)) usage(); if (fname != NULL) { /* Use output file */ if ((outfile = fopen(fname, "w")) == NULL) errx(1, "cannot open %s", fname); } /* * If truss starts the process itself, it will ignore some signals -- * they should be passed off to the process, which may or may not * exit. If, however, we are examining an already-running process, * then we restore the event mask on these same signals. */ if (pid == 0) { /* Start a command ourselves */ command = av; pid = setup_and_wait(command); signal(SIGINT, SIG_IGN); signal(SIGTERM, SIG_IGN); signal(SIGQUIT, SIG_IGN); } else { signal(SIGINT, restore_proc); signal(SIGTERM, restore_proc); signal(SIGQUIT, restore_proc); } /* * At this point, if we started the process, it is stopped waiting to * be woken up, either in exit() or in execve(). */ Procfd = start_tracing(pid, S_EXEC | S_SCE | S_SCX | S_CORE | S_EXIT | (nosigs ? 0 : S_SIG)); if (Procfd == -1) return 0; pfs.why = 0; funcs = set_etype(); /* * At this point, it's a simple loop, waiting for the process to * stop, finding out why, printing out why, and then continuing it. * All of the grunt work is done in the support routines. */ do { int val = 0; if (ioctl(Procfd, PIOCWAIT, &pfs) == -1) warn("PIOCWAIT top of loop"); else { switch(i = pfs.why) { case S_SCE: funcs->enter_syscall(pid, pfs.val); break; case S_SCX: /* * This is so we don't get two messages for an exec -- one * for the S_EXEC, and one for the syscall exit. It also, * conveniently, ensures that the first message printed out * isn't the return-from-syscall used to create the process. */ if (in_exec) { in_exec = 0; break; } funcs->exit_syscall(pid, pfs.val); break; case S_SIG: fprintf(outfile, "SIGNAL %lu\n", pfs.val); sigexit = pfs.val; break; case S_EXIT: fprintf (outfile, "process exit, rval = %lu\n", pfs.val); break; case S_EXEC: funcs = set_etype(); in_exec = 1; break; default: fprintf (outfile, "Process stopped because of: %d\n", i); break; } } if (ioctl(Procfd, PIOCCONT, val) == -1) { if (kill(pid, 0) == -1 && errno == ESRCH) break; else warn("PIOCCONT"); } } while (pfs.why != S_EXIT); fflush(outfile); if (sigexit) { if (sigexit == SIGQUIT) exit(sigexit); (void) signal(sigexit, SIG_DFL); (void) kill(getpid(), sigexit); } return 0; }