Fix logfile rotation to avoid program collapse.

[tripe] / client.c

/* -*-c-*-
 *
 * $Id: client.c,v 1.6 2001/02/22 09:06:08 mdw Exp $
 *
 * Client for TrIPE
 *
 * (c) 2001 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of Trivial IP Encryption (TrIPE).
 *
 * TrIPE is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * TrIPE is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with TrIPE; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*----- Revision history --------------------------------------------------* 
 *
 * $Log: client.c,v $
 * Revision 1.6  2001/02/22 09:06:08  mdw
 * Fix logfile rotation to avoid program collapse.
 *
 * Revision 1.5  2001/02/16 21:23:39  mdw
 * Use reliable signal handling for reopening logs.
 *
 * Revision 1.4  2001/02/06 09:34:53  mdw
 * Change ERR response to FAIL for consistency with other programs.
 *
 * Revision 1.3  2001/02/04 17:10:15  mdw
 * Reopen logfiles on receipt of @SIGHUP@ (not done very well).  Don't
 * change directory -- just mangle pathnames instead.
 *
 * Revision 1.2  2001/02/04 01:17:54  mdw
 * Create a configuration header file to tidy up command lines.
 *
 * Revision 1.1  2001/02/03 20:26:37  mdw
 * Initial checkin.
 *
 */

/*----- Header files ------------------------------------------------------*/

#include "config.h"

#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

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

#include <sys/socket.h>
#include <sys/un.h>
#include <arpa/inet.h>
#include <netdb.h>

#include <mLib/alloc.h>
#include <mLib/darray.h>
#include <mLib/dstr.h>
#include <mLib/mdwopt.h>
#include <mLib/quis.h>
#include <mLib/report.h>
#include <mLib/sel.h>
#include <mLib/selbuf.h>
#include <mLib/sig.h>
#include <mLib/str.h>

#include "util.h"

#undef sun

/*----- Data structures ---------------------------------------------------*/

#ifndef STRING_V
#  define STRING_V
   DA_DECL(string_v, char *);
#endif

/*----- Static variables --------------------------------------------------*/

static FILE *logfp = 0;
static unsigned f = 0;
static const char *logname = 0;
static int fd;

#define f_bogus 1u
#define f_spawn 2u
#define f_daemon 4u
#define f_spawnopts 8u
#define f_syslog 16u
#define f_command 32u
#define f_noinput 64u
#define f_warn 128u
#define f_uclose 256u

/*----- Main code ---------------------------------------------------------*/

static void reap(int sig)
{
  int s;
  int e = errno;
  while (waitpid(-1, &s, WNOHANG) > 0)
    ;
  errno = e;
}

static void writelog(const char *cat, const char *msg)
{
  char buf[256];
  time_t t = time(0);
  struct tm *tm = localtime(&t);
  strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", tm);
  fprintf(logfp, "%s %s: %s\n", buf, cat, msg);
}

static void cline(char *p, void *b)
{
  char *q;
  if (!p) {
    if (f & f_command)
      die(EXIT_FAILURE, "server dropped the connection");
    exit(0);
  }
  q = str_getword(&p);
  if (!q)
    return;
  if (strcmp(q, "WARN") == 0) {
    if (f & f_syslog)
      syslog(LOG_WARNING, "%s", p);
    if (logfp)
      writelog("warning", p);
    if (f & f_warn)
      fprintf(stderr, "Warning: %s\n", p);
  } else if (strcmp(q, "TRACE") == 0) {
    if (f & f_syslog)
      syslog(LOG_DEBUG, "%s", p);
    if (logfp)
      writelog("debug", p);
  } else if (!(f & f_command)) {
    if (f & f_syslog)
      syslog(LOG_ERR, "unexpected output `%s %s'", q, p);
    if (logfp) {
      dstr d = DSTR_INIT;
      dstr_putf(&d, "unexpected output `%s %s'", q, p);
      writelog("error", d.buf);
      dstr_destroy(&d);
    }
  } else if (strcmp(q, "FAIL") == 0)
    die(EXIT_FAILURE, "%s", p);
  else if (strcmp(q, "INFO") == 0)
    puts(p);
  else if (strcmp(q, "OK") == 0)
    exit(0);
  else
    die(EXIT_FAILURE, "unexpected output `%s %s'", q, p); 
}

static void sline(char *p, void *b)
{
  if (!p) {
    if (!(f & f_uclose))
      moan("server closed the connection");
    exit(0);
  }
  puts(p);
}

static void uline(char *p, void *b)
{
  size_t sz;
  if (!p) {
    selbuf_destroy(b);
    shutdown(fd, 1);
    f |= f_uclose;
  } else {
    sz = strlen(p);
    p[sz] = '\n';
    write(fd, p, sz + 1);
  }
}

static void logfile(const char *name)
{
  FILE *fp;

  if ((fp = fopen(name, "a")) != 0) {
    if (logfp)
      fclose(logfp);
    logfp =  fp;
    setvbuf(logfp, 0, _IOLBF, BUFSIZ);
  } else {
    dstr d = DSTR_INIT;
    dstr_putf(&d, "error opening logfile `%s': %s", name, strerror(errno));
    if (logfp)
      writelog("error", d.buf);
    else if (logname)
      die(EXIT_FAILURE, d.buf);
    if (f & f_syslog)
      syslog(LOG_ERR, d.buf);
    dstr_destroy(&d);
  }
}

static void sighup(int sig, void *v)
{
  logfile(logname);
}

static void version(FILE *fp)
{
  pquis(fp, "$, TrIPE version " VERSION "\n");
}

static void usage(FILE *fp)
{
  pquis(fp, "\
Usage:\n\
	$ [-w] [-options] [command [args]...]\n\
	$ [-Dl] [-f file] [-options]\n\
Options:\n\
	[-s] [-d directory] [-a socket] [-p program] [-S arg,arg,...]\n\
");
}

static void help(FILE *fp)
{
  version(fp);
  fputc('\n', fp);
  usage(fp);
  fputs("\
\n\
Options in full:\n\
\n\
-h, --help		Show this help text.\n\
-v, --version		Show version number.\n\
-u, --usage		Show brief usage message.\n\
\n\
-D, --daemon		Become a background task after connecting.\n\
-d, --directory=DIR	Select current directory [default /var/lib/tripe]\n\
-a, --admin-socket=FILE	Select socket to connect to.\n\
\n\
-s, --spawn		Start server rather than connecting.\n\
-p, --spawn-path=PATH	Specify path to executable.\n\
-S, --spawn-args=ARGS	Specify comma-separated arguments.\n\
\n\
-l, --syslog		Log messages to system log.\n\
-f, --logfile=FILE	Log messages to FILE.\n\
-w, --warnings		Show warnings when running commands.\n\
", fp);
}

int main(int argc, char *argv[])
{
  const char *dir = "/var/lib/tripe";
  const char *sock = "tripesock";
  const char *spawnpath = "tripe";
  string_v spawnopts = DA_INIT;
  char *p;

  ego(argv[0]);

  if ((p = getenv("TRIPEDIR")) != 0)
    dir = p;

  /* --- Parse the arguments --- */

  for (;;) {
    static const struct option opts[] = {
      { "help",		0,		0,	'h' },
      { "version",	0,		0,	'v' },
      { "usage",	0,		0,	'u' },
      { "daemon",	0,		0,	'D' },
      { "directory",	OPTF_ARGREQ,	0,	'd' },
      { "admin-socket",	OPTF_ARGREQ,	0,	'a' },
      { "spawn",	0,		0,	's' },
      { "spawn-path",	OPTF_ARGREQ,	0,	'p' },
      { "spawn-args",	OPTF_ARGREQ,	0,	'S' },
      { "syslog",	0,		0,	'l' },
      { "logfile",	OPTF_ARGREQ,	0,	'f' },
      { "warnings",	0,		0,	'w' },
      { 0,		0,		0,	0 }
    };

    int i = mdwopt(argc, argv, "hvuDd:a:sp:S:lwf:n", opts, 0, 0, 0);
    if (i < 0)
      break;
    switch (i) {
      case 'h':
	help(stdout);
	exit(0);
      case 'v':
	version(stdout);
	exit(0);
      case 'u':
	usage(stdout);
	exit(0);
      case 'D':
	f |= f_daemon | f_noinput;
	break;
      case 'd':
	dir = optarg;
	break;
      case 'a':
	sock = optarg;
	break;
      case 's':
	f |= f_spawn;
	break;
      case 'p':
	f |= f_spawn;
	spawnpath = optarg;
	break;
      case 'S':
	f |= f_spawn | f_spawnopts;
	for (p = strtok(optarg, ","); p; p = strtok(0, ","))
	  DA_PUSH(&spawnopts, p);
	break;
      case 'l':
	f |= f_syslog | f_noinput;
	break;
      case 'w':
	f |= f_warn;
	break;
      case 'f':
	logname = optarg;
	logfile(logname);
	f |= f_noinput;
	break;
      default:
	f |= f_bogus;
	break;
    }
  }
  if ((f & f_bogus) || ((f & f_noinput) && optind < argc)) {
    usage(stderr);
    exit(EXIT_FAILURE);
  }

  /* --- Connect to the server --- */

  if (f & f_spawn) {
    int pfd[2];
    pid_t kid;
    struct sigaction sa;
    sigset_t newmask, oldmask;

    sa.sa_handler = reap;
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = SA_NOCLDSTOP;
#ifdef SA_RESTART
    sa.sa_flags |= SA_RESTART;
#endif
    sigaction(SIGCHLD, &sa, 0);

    DA_UNSHIFT(&spawnopts, (char *)spawnpath);
    if (!(f & f_spawnopts)) {
      DA_PUSH(&spawnopts, "-d");
      DA_PUSH(&spawnopts, (char *)dir);
      DA_PUSH(&spawnopts, "-a");
      DA_PUSH(&spawnopts, (char *)sock);
    }
    DA_PUSH(&spawnopts, 0);
    if (socketpair(PF_UNIX, SOCK_STREAM, 0, pfd))
      die(EXIT_FAILURE, "error from socketpair: %s", strerror(errno));
    sigemptyset(&newmask);
    sigaddset(&newmask, SIGCHLD);
    sigprocmask(SIG_BLOCK, &newmask, &oldmask);
    if ((kid = fork()) < 0)
      die(EXIT_FAILURE, "fork failed: %s", strerror(errno));
    if (!kid) {
      dup2(pfd[1], STDIN_FILENO);
      dup2(pfd[1], STDOUT_FILENO);
      close(pfd[1]);
      close(pfd[0]);
      if (logfp)
	fclose(logfp);
      closelog();
      execvp(DA(&spawnopts)[0], DA(&spawnopts));
      die(127, "couldn't exec `%s': %s", spawnpath, strerror(errno));
    }
    sigprocmask(SIG_SETMASK, &oldmask, 0);
    fd = pfd[0];
    close(pfd[1]);
  } else {
    struct sockaddr_un sun;
    size_t sz = strlen(sock) + 1;
    dstr d = DSTR_INIT;
    dstr_putf(&d, "%s/%s", dir, sock);
    if (d.sz + 1 > sizeof(sun.sun_path))
      die(EXIT_FAILURE, "socket name `%s' too long", sock);
    memset(&sun, 0, sizeof(sun));
    sun.sun_family = AF_UNIX;
    memcpy(sun.sun_path, d.buf, d.sz + 1);
    sz = d.sz + offsetof(struct sockaddr_un, sun_path) + 1;
    dstr_destroy(&d);
    if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
      die(EXIT_FAILURE, "error making socket: %s", strerror(errno));
    if (connect(fd, (struct sockaddr *)&sun, sz)) {
      die(EXIT_FAILURE, "error connecting to `%s': %s",
	  sun.sun_path, strerror(errno));
    }
  }

  if (f & f_daemon) {
    if (u_daemon())
      die(EXIT_FAILURE, "error becoming daemon: %s", strerror(errno));
  }

  /* --- If we're meant to be interactive, do that --- */

  if (!(f & f_noinput) && optind == argc) {
    sel_state sel;
    selbuf bu, bs;

    sel_init(&sel);
    selbuf_init(&bu, &sel, STDIN_FILENO, uline, &bu);
    selbuf_init(&bs, &sel, fd, sline, &bs);
    for (;;) {
      if (sel_select(&sel) && errno != EINTR && errno != EAGAIN)
	die(EXIT_FAILURE, "select failed: %s", strerror(errno));
    }
  }

  /* --- If there's a command, submit it --- */

  if (optind < argc) {
    dstr d = DSTR_INIT;
    dstr_puts(&d, argv[optind++]);
    while (optind < argc) {
      dstr_putc(&d, ' ');
      dstr_puts(&d, argv[optind++]);
    }
    dstr_putc(&d, '\n');
    write(fd, d.buf, d.len);
    shutdown(fd, 1);
    dstr_destroy(&d);
    f |= f_command;
  }

  /* --- Pull everything else out of the box --- */

  {
    sel_state sel;
    selbuf b;
    sig hup;

    sel_init(&sel);
    selbuf_init(&b, &sel, fd, cline, 0);

    if (f & f_syslog)
      openlog(QUIS, 0, LOG_DAEMON);
    if (logfp) {
      sig_init(&sel);
      sig_add(&hup, SIGHUP, sighup, 0);
    }
    for (;;) {
      if (sel_select(&sel) && errno != EINTR && errno != EAGAIN)
	die(EXIT_FAILURE, "select failed: %s", strerror(errno));
    }
  }

  return (0);
}

/*----- That's all, folks -------------------------------------------------*/