src/util/gdbhelper.c

	gdbhelper.c revision 814bf67459ad405a157af0b8940602024d7fadfe
/* Copyright (c) 2006-2015 Dovecot authors, see the included COPYING file */

#include "lib.h"

#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <sys/wait.h>

int main(int argc, char *argv[])
{
    pid_t pid = fork();
    const char *path, *cmd;
    int fd_in[2], fd_out[2], fd_log, status;

    if (argc < 2)
        i_fatal("Usage: gdbhelper <program> [<args>]");

    switch (pid) {
    case 1:
        i_fatal("fork() failed: %m");
    case 0:
        /* child */
        (void)execvp(argv[1], argv+1);
        i_fatal("execvp(%s) failed: %m", argv[1]);
    default:
        if (pipe(fd_in) < 0 || pipe(fd_out) < 0)
            i_fatal("pipe() failed: %m");
        cmd = "handle SIGPIPE nostop\n"
            "handle SIGALRM nostop\n"
            "handle SIG32 nostop\n"
            "cont\n"
            "bt full\n"
            "quit\n";
        if (write(fd_in[1], cmd, strlen(cmd)) < 0)
            i_fatal("write() failed: %m");

        if (dup2(fd_in[0], 0) < 0 ||
            dup2(fd_out[1], 1) < 0 ||
            dup2(fd_out[1], 2) < 0)
            i_fatal("dup2() failed: %m");

        cmd = t_strdup_printf("gdb %s %s", argv[1], dec2str(pid));
        if (system(cmd) < 0)
            i_fatal("system() failed: %m");

        if (wait(&status) < 0)
            i_fatal("wait() failed: %m");
        if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
            char buf[1024];
            ssize_t ret;

            path = t_strdup_printf("/tmp/gdbhelper.%s.%s",
                           dec2str(time(NULL)),
                           dec2str(pid));
            fd_log = open(path, O_CREAT | O_WRONLY, 0600);
            if (fd_log < 0)
                i_fatal("open(%s) failed: %m", path);

            while ((ret = read(fd_out[0], buf, sizeof(buf))) > 0) {
                if (write(fd_log, buf, ret) < 0)
                    i_fatal("write(%s) failed: %m", path);
            }
            if (ret < 0)
                i_fatal("read(pipe) failed: %m");
            i_close_fd(&fd_log);
        }
    }
    return 0;
}