/* -*-c-*-
*
- * $Id: fw.c,v 1.9 2001/01/20 11:55:17 mdw Exp $
+ * $Id: fw.c,v 1.14 2003/01/24 20:12:40 mdw Exp $
*
* Port forwarding thingy
*
/*----- Revision history --------------------------------------------------*
*
* $Log: fw.c,v $
+ * Revision 1.14 2003/01/24 20:12:40 mdw
+ * Correctly cast uid and gid sentinel values.
+ *
+ * Revision 1.13 2002/02/22 23:45:20 mdw
+ * Add option to change the listen(2) parameter. Receive `fw'-specific
+ * code from `conf.c'.
+ *
+ * Revision 1.12 2002/01/13 14:49:17 mdw
+ * Track @dstr_vputf@ change.
+ *
+ * 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.
*
#include "config.h"
+#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include "endpt.h"
#include "exec.h"
#include "fattr.h"
+#include "file.h"
#include "fw.h"
#include "scan.h"
+#include "socket.h"
#include "source.h"
/*----- Global variables --------------------------------------------------*/
/*----- Static variables --------------------------------------------------*/
+typedef struct conffile {
+ struct conffile *next;
+ char *name;
+} conffile;
+
static unsigned flags = 0; /* Global state flags */
static unsigned active = 0; /* Number of active things */
+static conffile *conffiles = 0; /* List of configuration files */
#define FW_SYSLOG 1u
#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);
+ }
+
+ /* --- 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);
static void fw_tidy(int n, void *p)
{
- const char *sn = "unexpected signal (bug!)";
- if (n == SIGTERM)
- sn = "SIGTERM";
- else if (n == SIGINT)
- sn = "SIGINT";
-
- fw_log(-1, "closing down on %s", sn);
- fw_exit();
+ const char *sn = 0;
+ switch (n) {
+ case SIGTERM: sn = "SIGTERM"; break;
+ case SIGINT: sn = "SIGINT"; break;
+ default: abort();
+ }
+
+ fw_log(-1, "closing down gracefully on %s", sn);
+ source_killall();
}
+/* --- @fw_die@ --- *
+ *
+ * Arguments: @int n@ = signal number
+ * @void *p@ = an uninteresting argument
+ *
+ * Returns: ---
+ *
+ * Use: Handles various signals and causes an abrupt shutdown.
+ */
+
+static void fw_die(int n, void *p)
+{
+ const char *sn = 0;
+ switch (n) {
+ case SIGQUIT: sn = "SIGQUIT"; break;
+ default: abort();
+ }
+
+ fw_log(-1, "closing down abruptly on %s", sn);
+ source_killall();
+ endpt_killall();
+}
+
+/* --- @fw_reload@ --- *
+ *
+ * Arguments: @int n@ = a signal number
+ * @void *p@ = an uninteresting argument
+ *
+ * Returns: ---
+ *
+ * Use: Handles a hangup signal by re-reading configuration files.
+ */
+
+static void fw_reload(int n, void *p)
+{
+ FILE *fp;
+ scanner sc;
+ conffile *cf;
+
+ assert(n == SIGHUP);
+ if (!conffiles) {
+ fw_log(-1, "no configuration files to reload: ignoring SIGHUP");
+ return;
+ }
+ fw_log(-1, "reloading configuration files...");
+ source_killall();
+ scan_create(&sc);
+ for (cf = conffiles; cf; cf = cf->next) {
+ if ((fp = fopen(cf->name, "r")) == 0)
+ fw_log(-1, "error loading `%s': %s", cf->name, strerror(errno));
+ else
+ scan_add(&sc, scan_file(fp, cf->name, 0));
+ }
+ parse(&sc);
+ fw_log(-1, "... reload completed OK");
+}
+
+/*----- Startup and options parsing ---------------------------------------*/
+
/* --- Standard GNU help options --- */
static void version(FILE *fp)
\n\
Socket options\n\
socket.conn [=] number|unlimited|one-shot\n\
+ socket.listen [=] number\n\
socket.logging [=] yes|no\n\
+\n\
socket.inet.[allow|deny] [from] address [/ address]\n\
+\n\
socket.unix.fattr.*\n\
");
}
{
unsigned f = 0;
sel_state sst;
- sig s_term, s_int;
+ sig s_term, s_quit, s_int, s_hup;
scanner sc;
uid_t drop = -1;
gid_t dropg = -1;
+ conffile *cf, **cff = &conffiles;
- enum {
- f_bogus = 1,
- f_file = 2,
- f_syslog = 4,
- f_fork = 8
- };
+#define f_bogus 1u
+#define f_file 2u
+#define f_syslog 4u
+#define f_fork 8u
/* --- Initialize things --- */
fattr_init(&fattr_global);
scan_create(&sc);
- /* --- Set up some signal handlers --- *
- *
- * Don't enable @SIGINT@ if the caller already disabled it.
- */
-
- {
- struct sigaction sa;
-
- sig_add(&s_term, SIGTERM, fw_tidy, 0);
- sigaction(SIGINT, 0, &sa);
- if (sa.sa_handler != SIG_IGN)
- sig_add(&s_int, SIGINT, fw_tidy, 0);
- }
-
atexit(fw_exit);
/* --- Parse command line options --- */
FILE *fp;
if ((fp = fopen(optarg, "r")) == 0)
die(1, "couldn't open file `%s': %s", optarg, strerror(errno));
+ cf = CREATE(conffile);
+ cf->name = optarg;
+ *cff = cf;
+ cff = &cf->next;
scan_add(&sc, scan_file(fp, optarg, 0));
}
f |= f_file;
usage(stderr);
exit(1);
}
+ *cff = 0;
/* --- Deal with the remaining arguments --- */
/* --- Parse the configuration now gathered --- */
- conf_parse(&sc);
+ parse(&sc);
+
+ /* --- Set up some signal handlers --- *
+ *
+ * Don't enable @SIGINT@ if the caller already disabled it.
+ */
+
+ {
+ struct sigaction sa;
+
+ sig_add(&s_term, SIGTERM, fw_tidy, 0);
+ sig_add(&s_quit, SIGQUIT, fw_die, 0);
+ sigaction(SIGINT, 0, &sa);
+ if (sa.sa_handler != SIG_IGN)
+ sig_add(&s_int, SIGINT, fw_tidy, 0);
+ 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)))
+ 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 != -1 && setgid(dropg)) ||
- (drop != -1 && setuid(drop)))
+ if ((dropg != (gid_t)-1 && setgid(dropg)) ||
+ (drop != (uid_t)-1 && setuid(drop)))
die(1, "couldn't drop privileges: %s", strerror(errno));
#endif
while (active) {
if (!sel_select(sel))
selerr = 0;
- else {
+ else if (errno != EINTR && errno != EAGAIN) {
fw_log(-1, "error from select: %s", strerror(errno));
selerr++;
if (selerr > 8) {
~mdw / fwd / blobdiff