/* -*-c-*-
*
- * $Id: fw.c,v 1.11 2001/02/03 20:33:26 mdw Exp $
- *
* Port forwarding thingy
*
* (c) 1999 Straylight/Edgeware
*/
-/*----- Licensing notice --------------------------------------------------*
+/*----- Licensing notice --------------------------------------------------*
*
* This file is part of the `fw' port forwarder.
*
* 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.
- *
+ *
* `fw' 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 `fw'; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: fw.c,v $
- * Revision 1.11 2001/02/03 20:33:26 mdw
- * Fix flags to be unsigned.
- *
- * Revision 1.10 2001/02/03 20:30:03 mdw
- * Support re-reading config files on SIGHUP.
- *
- * Revision 1.9 2001/01/20 11:55:17 mdw
- * Handle select errors more robustly.
- *
- * Revision 1.8 2000/03/23 23:19:19 mdw
- * Fix changed options in parser table.
- *
- * Revision 1.7 2000/03/23 00:37:33 mdw
- * Add option to change user and group after initialization. Naughtily
- * reassign short equivalents of --grammar and --options.
- *
- * Revision 1.6 1999/12/22 15:44:10 mdw
- * Make syslog a separate option, and do it better.
- *
- * Revision 1.5 1999/10/22 22:47:50 mdw
- * Grammar changes. Also, don't enable SIGINT if it's currently ignored.
- *
- * Revision 1.4 1999/10/10 16:46:12 mdw
- * New resolver to initialize. Also, include options for grammar and
- * options references.
- *
- * Revision 1.3 1999/07/26 23:30:42 mdw
- * Major reconstruction work for new design.
- *
- * Revision 1.2 1999/07/03 13:55:17 mdw
- * Various changes. Add configuration grammar to help text. Change to
- * root directory and open syslog when forking into background.
- *
- * Revision 1.1.1.1 1999/07/01 08:56:23 mdw
- * Initial revision.
- *
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-#include "config.h"
-
-#include <assert.h>
-#include <ctype.h>
-#include <errno.h>
-#include <signal.h>
-#include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-
-#include <unistd.h>
-#include <syslog.h>
-
-#include <grp.h>
-#include <pwd.h>
-
-#include <mLib/bres.h>
-#include <mLib/dstr.h>
-#include <mLib/mdwopt.h>
-#include <mLib/quis.h>
-#include <mLib/report.h>
-#include <mLib/sel.h>
-#include <mLib/sig.h>
-#include <mLib/sub.h>
-
-#include "conf.h"
-#include "endpt.h"
-#include "exec.h"
-#include "fattr.h"
#include "fw.h"
-#include "scan.h"
-#include "source.h"
/*----- Global variables --------------------------------------------------*/
#define FW_QUIET 2u
#define FW_SET 4u
-/*----- Main code ---------------------------------------------------------*/
+/*----- Configuration parsing ---------------------------------------------*/
+
+/* --- @parse@ --- *
+ *
+ * Arguments: @scanner *sc@ = pointer to scanner definition
+ *
+ * Returns: ---
+ *
+ * Use: Parses a configuration file from the scanner.
+ */
+
+static source_ops *sources[] =
+ { &xsource_ops, &fsource_ops, &ssource_ops, 0 };
+static target_ops *targets[] =
+ { &xtarget_ops, &ftarget_ops, &starget_ops, 0 };
+
+void parse(scanner *sc)
+{
+ token(sc);
+
+ for (;;) {
+ if (sc->t == CTOK_EOF)
+ break;
+ if (sc->t != CTOK_WORD)
+ error(sc, "parse error, keyword expected");
+
+ /* --- Handle a forwarding request --- */
+
+ if (strcmp(sc->d.buf, "forward") == 0 ||
+ strcmp(sc->d.buf, "fw") == 0 ||
+ strcmp(sc->d.buf, "from") == 0) {
+ source *s;
+ target *t;
+
+ token(sc);
+
+ /* --- Read a source description --- */
+
+ {
+ source_ops **sops;
+
+ /* --- Try to find a source type which understands --- */
+
+ s = 0;
+ for (sops = sources; *sops; sops++) {
+ if ((s = (*sops)->read(sc)) != 0)
+ goto found_source;
+ }
+ error(sc, "unknown source name `%s'", sc->d.buf);
+
+ /* --- Read any source-specific options --- */
+
+ found_source:
+ if (sc->t == '{') {
+ token(sc);
+ while (sc->t == CTOK_WORD) {
+ if (!s->ops->option || !s->ops->option(s, sc)) {
+ error(sc, "unknown %s source option `%s'",
+ s->ops->name, sc->d.buf);
+ }
+ if (sc->t == ';')
+ token(sc);
+ }
+ if (sc->t != '}')
+ error(sc, "parse error, missing `}'");
+ token(sc);
+ }
+ }
+
+ /* --- Read a destination description --- */
+
+ if (sc->t == CTOK_WORD && (strcmp(sc->d.buf, "to") == 0 ||
+ strcmp(sc->d.buf, "->") == 0))
+ token(sc);
+
+ {
+ target_ops **tops;
+
+ /* --- Try to find a target which understands --- */
+
+ t = 0;
+ for (tops = targets; *tops; tops++) {
+ if ((t = (*tops)->read(sc)) != 0)
+ goto found_target;
+ }
+ error(sc, "unknown target name `%s'", sc->d.buf);
+
+ /* --- Read any target-specific options --- */
+
+ found_target:
+ if (sc->t == '{') {
+ token(sc);
+ while (sc->t == CTOK_WORD) {
+ if (!t->ops->option || !t->ops->option(t, sc)) {
+ error(sc, "unknown %s target option `%s'",
+ t->ops->name, sc->d.buf);
+ }
+ if (sc->t == ';')
+ token(sc);
+ }
+ if (sc->t != '}')
+ error(sc, "parse error, `}' expected");
+ token(sc);
+ }
+ }
+
+ /* --- Combine the source and target --- */
+
+ s->ops->attach(s, sc, t);
+ if (t->ops->confirm)
+ t->ops->confirm(t);
+ }
+
+ /* --- Include configuration from a file --- *
+ *
+ * Slightly tricky. Scan the optional semicolon from the including
+ * stream, not the included one.
+ */
+
+ else if (strcmp(sc->d.buf, "include") == 0) {
+ FILE *fp;
+ dstr d = DSTR_INIT;
+
+ token(sc);
+ conf_name(sc, '/', &d);
+ if ((fp = fopen(d.buf, "r")) == 0)
+ error(sc, "can't include `%s': %s", d.buf, strerror(errno));
+ if (sc->t == ';')
+ token(sc);
+ pushback(sc);
+ scan_push(sc, scan_file(fp, d.buf, 0));
+ token(sc);
+ dstr_destroy(&d);
+ continue; /* Don't parse a trailing `;' */
+ }
+
+ /* --- Other configuration is handled elsewhere --- */
+
+ else {
+
+ /* --- First try among the sources --- */
+
+ {
+ source_ops **sops;
+
+ for (sops = sources; *sops; sops++) {
+ if ((*sops)->option && (*sops)->option(0, sc))
+ goto found_option;
+ }
+ }
+
+ /* --- Then try among the targets --- */
+
+ {
+ target_ops **tops;
+
+ for (tops = targets; *tops; tops++) {
+ if ((*tops)->option && (*tops)->option(0, sc))
+ goto found_option;
+ }
+ }
+
+ /* --- Nobody wants the option --- */
+
+ error(sc, "unknown global option or prefix `%s'", sc->d.buf);
+
+ found_option:;
+ }
+
+ if (sc->t == ';')
+ token(sc);
+ }
+}
+
+/*----- General utility functions -----------------------------------------*/
/* --- @fw_log@ --- *
*
DENSURE(&d, 64);
d.len += strftime(d.buf, d.sz, "%Y-%m-%d %H:%M:%S ", tm);
va_start(ap, fmt);
- dstr_vputf(&d, fmt, ap);
+ dstr_vputf(&d, fmt, &ap);
va_end(ap);
if (flags & FW_SYSLOG)
syslog(LOG_NOTICE, "%s", d.buf);
else
scan_add(&sc, scan_file(fp, cf->name, 0));
}
- conf_parse(&sc);
+ parse(&sc);
fw_log(-1, "... reload completed OK");
}
+/*----- Startup and options parsing ---------------------------------------*/
+
/* --- Standard GNU help options --- */
static void version(FILE *fp)
static void usage(FILE *fp)
{
- pquis(fp, "Usage: $ [-dql] [-f file] [config statements...]\n");
+ pquis(fp, "Usage: $ [-dql] [-p PIDFILE] [-f FILE] [CONFIG-STMTS...]\n");
}
static void help(FILE *fp)
usage(fp);
pquis(fp, "\n\
An excessively full-featured port-forwarder, which subsumes large chunks\n\
-of the functionality of inetd, netcat, and normal cat. Options available\n\
-are:\n\
-\n\
--h, --help Display this help message.\n\
--v, --version Display the program's version number.\n\
--u, --usage Display a terse usage summary.\n\
-\n\
--G, --grammar Show a summary of the configuration language.\n\
--O, --options Show a summary of the source and target options.\n\
-\n\
--f, --file=FILE Read configuration from a file.\n\
--q, --quiet Don't emit any logging information.\n\
--d, --daemon Fork into background after initializing.\n\
--l, --syslog Send log output to the system logger.\n\
--s, --setuid=USER Change uid to USER after initializing sources.\n\
--g, --setgid=GRP Change gid to GRP after initializing sources.\n\
+of the functionality of inetd, netcat, and normal cat.\n\
\n\
Configuration may be supplied in one or more configuration files, or on\n\
the command line (or both). If no `-f' option is present, and no\n\
\n\
The grammar is fairly complicated. For a summary, run `$ --grammar'.\n\
For a summary of the various options, run `$ --options'.\n\
+\n\
+Options available are:\n\
+\n\
+Help options:\n\
+ -h, --help Display this help message.\n\
+ -v, --version Display the program's version number.\n\
+ -u, --usage Display a terse usage summary.\n\
+\n\
+Configuration summary:\n\
+ -G, --grammar Show a summary of the configuration language.\n\
+ -O, --options Show a summary of the source and target options.\n\
+\n\
+Other options:\n\
+ -f, --file=FILE Read configuration from a file.\n\
+ -q, --quiet Don't emit any logging information.\n\
+ -d, --daemon Fork into background after initializing.\n\
+ -p, --pidfile=FILE Write process-id to the named FILE.\n\
+ -l, --syslog Send log output to the system logger.\n\
+ -s, --setuid=USER Change uid to USER after initializing sources.\n\
+ -g, --setgid=GRP Change gid to GRP after initializing sources.\n\
");
}
static void grammar(FILE *fp)
{
version(fp);
- pquis(fp, "\n\
-Grammar summary\n\
-\n\
-Basic syntax\n\
- file ::= empty | file stmt [`;']\n\
- stmt ::= option-stmt | fw-stmt\n\
- fw-stmt ::= `fw' source options [`to'|`->'] target options\n\
- options ::= `{' option-seq `}'\n\
- option-seq ::= empty | option-stmt [`;'] option-seq\n\
-\n\
-Option syntax\n\
- option-stmt ::= q-option\n\
- q-option ::= option\n\
- | prefix `.' q-option\n\
- | prefix `{' option-seq `}'\n\
- prefix ::= word\n\
-\n\
-File source and target\n\
- source ::= file\n\
- target ::= file\n\
- file ::= `file' [`.'] fspec [`,' fspec]\n\
- fspec ::= fd-spec | name-spec | null-spec\n\
- fd-spec ::= [[`:']`fd'[`:']] number|`stdin'|`stdout'\n\
- name-spec ::= [[`:']`file'[`:']] file-name\n\
- file-name ::= path-seq | [ path-seq ]\n\
- path-seq ::= path-elt | path-seq path-elt\n\
- path-elt ::= `/' | word\n\
- null-spec ::= [`:']`null'[`:']\n\
-\n\
-Exec source and target\n\
- source ::= exec\n\
- target ::= exec\n\
- exec ::= `exec' [`.'] cmd-spec\n\
- cmd-spec ::= shell-cmd | [prog-name] `[' argv0 arg-seq `]'\n\
- arg-seq ::= word | arg-seq word\n\
- shell-cmd ::= word\n\
- argv0 ::= word\n\
-\n\
-Socket source and target\n\
- source ::= socket-source\n\
- target ::= socket-target\n\
- socket-source ::= [`socket'[`.']] [[`:']addr-type[`:']] source-addr\n\
- socket-target ::= [`socket'[`.']] [[`:']addr-type[`:']] target-addr\n\
-\n\
- inet-source-addr ::= [port] port\n\
- inet-target-addr ::= address [`:'] port\n\
- address ::= addr-elt | address addr-elt\n\
- addr-elt ::= `.' | word\n\
-\n\
- unix-source-addr ::= file-name\n\
- unix-target-addr ::= file-name\n\
-");
+ fputs("\nGrammar summary\n\n", fp);
+ fputs(grammar_text, fp);
}
static void options(FILE *fp)
{
version(fp);
- pquis(fp, "\n\
-Options summary\n\
-\n\
-File attributes (`fattr')\n\
- prefix.fattr.mode [=] mode\n\
- prefix.fattr.owner [=] user\n\
- prefix.fattr.group [=] group\n\
-\n\
-File options\n\
- file.create [=] yes|no\n\
- file.open [=] no|truncate|append\n\
- file.fattr.*\n\
-\n\
-Exec options\n\
- exec.logging [=] yes|no\n\
- exec.dir [=] file-name\n\
- exec.root [=] file-name\n\
- exec.user [=] user\n\
- exec.group [=] group\n\
- exec.rlimit.limit[.hard|.soft] [=] value\n\
- exec.env.clear\n\
- exec.env.unset var\n\
- exec.env.[set] var [=] value\n\
-\n\
-Socket options\n\
- socket.conn [=] number|unlimited|one-shot\n\
- socket.logging [=] yes|no\n\
- socket.inet.[allow|deny] [from] address [/ address]\n\
- socket.unix.fattr.*\n\
-");
+ fputs("\nOption summary\n\n", fp);
+ fputs(option_text, fp);
}
/* --- @main@ --- *
scanner sc;
uid_t drop = -1;
gid_t dropg = -1;
+ const char *pidfile = 0;
conffile *cf, **cff = &conffiles;
#define f_bogus 1u
{ "file", OPTF_ARGREQ, 0, 'f' },
{ "fork", 0, 0, 'd' },
{ "daemon", 0, 0, 'd' },
+ { "pidfile", OPTF_ARGREQ, 0, 'p' },
{ "syslog", 0, 0, 'l' },
{ "log", 0, 0, 'l' },
{ "quiet", 0, 0, 'q' },
{ 0, 0, 0, 0 }
};
- int i = mdwopt(argc, argv, "+hvu GO f:dls:g:", opts, 0, 0, 0);
+ int i = mdwopt(argc, argv, "+hvu" "GO" "f:dp:ls:g:", opts, 0, 0, 0);
if (i < 0)
break;
case 'd':
f |= f_fork;
break;
+ case 'p':
+ pidfile = optarg;
+ break;
case 'l':
f |= f_syslog;
break;
flags |= FW_QUIET;
break;
case 's':
- if (isdigit((unsigned char )optarg[0])) {
+ if (isdigit((unsigned char )optarg[0])) {
char *q;
drop = strtol(optarg, &q, 0);
if (*q)
}
break;
case 'g':
- if (isdigit((unsigned char )optarg[0])) {
+ if (isdigit((unsigned char )optarg[0])) {
char *q;
dropg = strtol(optarg, &q, 0);
if (*q)
/* --- Parse the configuration now gathered --- */
- conf_parse(&sc);
+ parse(&sc);
/* --- Set up some signal handlers --- *
*
sig_add(&s_hup, SIGHUP, fw_reload, 0);
}
- /* --- Drop privileges --- */
-
-#ifdef HAVE_SETGROUPS
- if ((dropg != -1 && (setgid(dropg) || setgroups(1, &dropg))) ||
- (drop != -1 && setuid(drop)))
- die(1, "couldn't drop privileges: %s", strerror(errno));
-#else
- if ((dropg != -1 && setgid(dropg)) ||
- (drop != -1 && setuid(drop)))
- die(1, "couldn't drop privileges: %s", strerror(errno));
-#endif
-
/* --- Fork into the background --- */
if (f & f_fork) {
if (kid != 0)
_exit(0);
}
+ if (pidfile) {
+ FILE *fp = fopen(pidfile, "w");
+ if (!fp) {
+ die(EXIT_FAILURE, "couldn't create pidfile `%s': %s",
+ pidfile, strerror(errno));
+ }
+ fprintf(fp, "%lu\n", (unsigned long)getpid());
+ if (fflush(fp) || ferror(fp) || fclose(fp)) {
+ die(EXIT_FAILURE, "couldn't write pidfile `%s': %s",
+ pidfile, strerror(errno));
+ }
+ }
if (f & f_syslog) {
flags |= FW_SYSLOG;
openlog(QUIS, 0, LOG_DAEMON);
}
+ /* --- Drop privileges --- */
+
+ if (drop != (uid_t)-1)
+ privconn_split(sel);
+#ifdef HAVE_SETGROUPS
+ if ((dropg != (gid_t)-1 && (setgid(dropg) || setgroups(1, &dropg))) ||
+ (drop != (uid_t)-1 && setuid(drop)))
+ die(1, "couldn't drop privileges: %s", strerror(errno));
+#else
+ if ((dropg != (gid_t)-1 && setgid(dropg)) ||
+ (drop != (uid_t)-1 && setuid(drop)))
+ die(1, "couldn't drop privileges: %s", strerror(errno));
+#endif
+
/* --- Let rip --- */
if (!(flags & FW_SET))
int selerr = 0;
while (active) {
if (!sel_select(sel))
- selerr = 0;
+ selerr = 0;
else if (errno != EINTR && errno != EAGAIN) {
fw_log(-1, "error from select: %s", strerror(errno));
selerr++;
}
}
}
-
+
return (0);
}
~mdw / fwd / blobdiff