X-Git-Url: https://git.distorted.org.uk/~mdw/fwd/blobdiff_plain/e0ce9d387ef6ee881ef99317161eec97ebdcee38..547dc0e8658f6a734abcbb0a802e39ae6f6f52a2:/socket.c

diff --git a/socket.c b/socket.c
index 6df5c4d..bbc1f9e 100644
--- a/socket.c
+++ b/socket.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: socket.c,v 1.2 1999/07/27 18:30:53 mdw Exp $
+ * $Id: socket.c,v 1.11 2003/11/29 20:36:07 mdw Exp $
  *
  * Socket source and target definitions
  *
@@ -29,6 +29,35 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: socket.c,v $
+ * Revision 1.11  2003/11/29 20:36:07  mdw
+ * Privileged outgoing connections.
+ *
+ * Revision 1.10  2003/11/25 14:08:23  mdw
+ * Debianization.  Socket target options.  Internet binding.
+ *
+ * Revision 1.9  2002/02/23 00:08:00  mdw
+ * Fix stupid bugs from the listen(2) change.
+ *
+ * Revision 1.8  2002/02/22 23:44:44  mdw
+ * Call @xfree@ rather than @free@.  Add option to change the listen(2)
+ * parameter.
+ *
+ * Revision 1.7  2001/06/22 19:37:00  mdw
+ * New @conn_init@ interface.
+ *
+ * Revision 1.6  2001/02/03 20:30:03  mdw
+ * Support re-reading config files on SIGHUP.
+ *
+ * Revision 1.5  2000/03/23 23:20:42  mdw
+ * Remove listener even if connection option isn't SOCKOPT_LIMITED.
+ *
+ * Revision 1.4  1999/12/22 15:44:25  mdw
+ * Fix log message.
+ *
+ * Revision 1.3  1999/10/22 22:48:36  mdw
+ * New connection options: unlimited concurrent connections, and one-shot
+ * listening sockets.
+ *
  * Revision 1.2  1999/07/27 18:30:53  mdw
  * Various minor portability fixes.
  *
@@ -43,6 +72,7 @@
 
 #include <ctype.h>
 #include <errno.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -78,10 +108,16 @@
 /* --- Socket source options --- */
 
 typedef struct ssource_opts {
+  unsigned opt;
   unsigned conn;
+  unsigned listen;
 } ssource_opts;
 
-static ssource_opts ssgo = { 256 };
+static ssource_opts ssgo = { 256, 0, 5 };
+
+#define SOCKOPT_LIMIT 0u
+#define SOCKOPT_NOLIMIT 1u
+#define SOCKOPT_ONESHOT 2u
 
 /* --- Socket source --- */
 
@@ -107,7 +143,7 @@ typedef struct starget {
 typedef struct stept {
   endpt e;
   conn c;
-  const char *desc;
+  char *desc;
 } stept;
 
 /* --- Socket source endpoint --- */
@@ -117,16 +153,13 @@ typedef struct ssept {
   ssource *s;
 } ssept;
 
-#define SKF_CONN 16u
-#define SKF_BROKEN 32u
-
 /*----- Protocol table ----------------------------------------------------*/
 
 static addr_ops *addrs[] = { &inet_ops, &un_ops, 0 };
 
 /*----- Other persistent variables ----------------------------------------*/
 
-static addr_opts gao = { 0 };
+static addr_opts gsao = { 0 }, gtao = { 0 };
 
 /*----- Parsing address types ---------------------------------------------*/
 
@@ -213,11 +246,11 @@ static void ssept_close(endpt *e)
 {
   ssept *ee = (ssept *)e;
 
-  if (!ee->s->o.conn) {
-    ee->s->o.conn++;
-    ss_listen(ee->s);
-  } else
+  if (ee->s->o.opt == SOCKOPT_LIMIT) {
     ee->s->o.conn++;
+    if (ee->s->o.conn == 1)
+      ss_listen(ee->s);
+  }
   REFFD_DEC(ee->e.in);
   REFFD_DEC(ee->e.out);
   fw_dec();
@@ -230,19 +263,19 @@ static void stept_close(endpt *e)
 {
   stept *ee = (stept *)e;
 
-  if (ee->e.f & EPF_PENDING) {
-    if (ee->e.f & SKF_CONN)
-      conn_kill(&ee->c);
-  } else {
+  if (ee->e.f & EPF_PENDING)
+    conn_kill(&ee->c);
+  else {
     REFFD_DEC(ee->e.in);
     REFFD_DEC(ee->e.out);
   }
 
+  xfree(ee->desc);
   fw_dec();
   DESTROY(ee);
 }
 
-/* --- @stept_go@ --- *
+/* --- @starget_connected@ --- *
  *
  * Arguments:	@int fd@ = file descriptor now ready for use
  *		@void *p@ = pointer to an endpoint structure
@@ -252,39 +285,21 @@ static void stept_close(endpt *e)
  * Use:		Handles successful connection of the target endpoint.
  */
 
-static void stept_go(int fd, void *p)
+void starget_connected(int fd, void *p)
 {
   stept *e = p;
 
-  /* --- Complicated and subtle --- *
-   *
-   * This code interacts quite closely with @starget_create@, mainly through
-   * flags in the endpoint block.
-   *
-   * If the connection failed, I log a message (that's easy enough).  The
-   * behaviour then depends on whether the endpoints have been joined yet.
-   * If not, I set @SKF_BROKEN@ and return, so that @starget_create@ can
-   * clean up the mess and return an immediate failure.  If they have, I kill
-   * the connection and everything ought to work.
-   *
-   * If the connection worked, I clear @EPF_PENDING@ (as expected, because
-   * my endpoint is now ready), and @SKF_CONN@ (to let @starget_create@ know
-   * that the connection is already going).  Then, only if this isn't the
-   * first attempt, I rejoin this endpoint to its partner.
-   */
-
   if (fd == -1) {
     fw_log(-1, "[%s] connection failed: %s", e->desc, strerror(errno));
-    e->e.f &= ~SKF_CONN;
-    if (e->e.f & EPF_PENDING)
-      endpt_kill(&e->e);
-    else
-      e->e.f |= SKF_BROKEN;
+    endpt_kill(&e->e);
   } else {
     reffd *r = reffd_init(fd);
+    int opt = 1;
     REFFD_INC(r);
+    fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
+    setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
     e->e.in = e->e.out = r;
-    e->e.f &= ~(EPF_PENDING | SKF_CONN);
+    e->e.f &= ~EPF_PENDING;
     if (e->e.other)
       endpt_join(&e->e, e->e.other);
   }
@@ -293,11 +308,11 @@ static void stept_go(int fd, void *p)
 /* --- Socket endpoint definition --- */
 
 static endpt_ops ssept_ops = {
-  0, sept_wclose, ssept_close
+  0, 0, sept_wclose, ssept_close
 };
 
 static endpt_ops stept_ops = {
-  0, sept_wclose, stept_close
+  0, 0, sept_wclose, stept_close
 };
 
 /*----- Source definition -------------------------------------------------*/
@@ -309,7 +324,7 @@ static int ssource_option(source *s, scanner *sc)
   ssource *ss = (ssource *)s;
   ssource_opts *sso = ss ? &ss->o : &ssgo;
 
-  CONF_BEGIN(sc, "socket", "socket")
+  CONF_BEGIN(sc, "socket", "socket source")
 
   /* --- Make sure the next token is a word --- */
 
@@ -322,18 +337,39 @@ static int ssource_option(source *s, scanner *sc)
     token(sc);
     if (sc->t == '=')
       token(sc);
+    if (sc->t != CTOK_WORD)
+      error(sc, "parse error, expected `unlimited', `one-shot' or number");
+    if (isdigit((unsigned char)sc->d.buf[0])) {
+      sso->conn = atoi(sc->d.buf);
+      if (sso->conn == 0)
+	error(sc, "argument of `conn' must be positive");
+      sso->opt = SOCKOPT_LIMIT;
+      token(sc);
+    } else {
+      sso->conn = 0;
+      sso->opt = 1 + (1 & conf_enum(sc,
+				    "unlimited,one-shot,infinite",
+				    ENUM_ABBREV, "`conn' option"));
+    }
+    CONF_ACCEPT;
+  }
+
+  if (strcmp(sc->d.buf, "listen") == 0) {
+    token(sc);
+    if (sc->t == '=')
+      token(sc);
     if (sc->t != CTOK_WORD || !isdigit((unsigned char)sc->d.buf[0]))
-      error(sc, "parse error, argument of `conn' must be a number");
-    sso->conn = atoi(sc->d.buf);
-    if (sso->conn == 0)
-      error(sc, "argument of `conn' must be positive");
+      error(sc, "parse error, expected number");
+    sso->listen = atoi(sc->d.buf);
+    if (sso->listen == 0)
+      error(sc, "argument of `listen' must be positive");
     token(sc);
     CONF_ACCEPT;
   }
 
   if (strcmp(sc->d.buf, "logging") == 0 ||
       strcmp(sc->d.buf, "log") == 0) {
-    addr_opts *ao = ss ? ss->ao : &gao;
+    addr_opts *ao = ss ? ss->ao : &gsao;
     token(sc);
     if (sc->t == '=')
       token(sc);
@@ -347,12 +383,12 @@ static int ssource_option(source *s, scanner *sc)
   /* --- Pass the option around the various address types --- */
 
   if (ss) {
-    if (ss->a->ops->option && ss->a->ops->option(sc, ss ? ss->ao : 0))
+    if (ss->a->ops->option && ss->a->ops->option(sc, ss->ao, ADDR_SRC))
       CONF_ACCEPT;
   } else {
     addr_ops **a;
     for (a = addrs; *a; a++) {
-      if ((*a)->option && (*a)->option(sc, 0))
+      if ((*a)->option && (*a)->option(sc, 0, ADDR_GLOBAL))
 	CONF_ACCEPT;
     }
   }
@@ -374,11 +410,11 @@ static source *ssource_read(scanner *sc)
   ss->s.desc = 0;
   ss->t = 0;
   ss->a = getaddr(sc, ADDR_SRC);
-  if (ss->a->ops->initopts)
-    ss->ao = ss->a->ops->initopts();
+  if (ss->a->ops->initsrcopts)
+    ss->ao = ss->a->ops->initsrcopts();
   else
     ss->ao = CREATE(addr_opts);
-  *ss->ao = gao;
+  *ss->ao = gsao;
   ss->o = ssgo;
   return (&ss->s);
 }
@@ -395,6 +431,8 @@ static source *ssource_read(scanner *sc)
  *		endpoint.
  */
 
+static void ssource_destroy(source */*s*/);
+
 static void ss_accept(int fd, unsigned mode, void *p)
 {
   ssource *ss = p;
@@ -431,21 +469,35 @@ static void ss_accept(int fd, unsigned mode, void *p)
     DESTROY(e);
     return;
   }
+  fw_inc();
 
   /* --- Remove the listening socket if necessary --- */
 
-  ss->o.conn--;
-  if (!ss->o.conn) {
-    fw_log(-1, "[%s] maximum connections reached", ss->s.desc);
-    sel_rmfile(&ss->r);
-    close(ss->r.fd);
-    if (ss->a->ops->unbind)
-      ss->a->ops->unbind(ss->a);
+  switch (ss->o.opt) {
+    case SOCKOPT_LIMIT:
+      ss->o.conn--;
+      if (!ss->o.conn) {
+	if (!(ss->ao->f & ADDRF_NOLOG))
+	  fw_log(-1, "[%s] maximum connections reached", ss->s.desc);
+	sel_rmfile(&ss->r);
+	close(ss->r.fd);
+	if (ss->a->ops->unbind)
+	  ss->a->ops->unbind(ss->a);
+      }
+      break;
+    case SOCKOPT_NOLIMIT:
+      break;
+    case SOCKOPT_ONESHOT:
+      sel_rmfile(&ss->r);
+      close(ss->r.fd);
+      if (ss->a->ops->unbind)
+	ss->a->ops->unbind(ss->a);
+      ssource_destroy(&ss->s);
+      break;
   }
 
   /* --- Let everything else happen --- */
 
-  fw_inc();
   endpt_join(&e->e, ee);
 }
 
@@ -461,43 +513,27 @@ static void ss_accept(int fd, unsigned mode, void *p)
  *		behaviour.
  */
 
-static void ssource_destroy(source */*s*/);
-
 static void ss_listen(ssource *ss)
 {
-  gen_addr *ga = (gen_addr *)ss->a;
   int fd;
+  int opt = 1;
 
-  fw_log(-1, "[%s] reattaching listener", ss->s.desc);
+  if (!(ss->ao->f & ADDRF_NOLOG))
+    fw_log(-1, "[%s] reattaching listener", ss->s.desc);
 
   /* --- Make the socket --- */
 
-  if ((fd = socket(ga->a.ops->pf, SOCK_STREAM, 0)) < 0) {
+  if ((fd = ss->a->ops->bind(ss->a, ss->ao)) < 0) {
     fw_log(-1, "[%s] couldn't create socket: %s",
 	   ss->s.desc, strerror(errno));
     goto fail_0;
   }
 
-  /* --- Set it to allow address reuse --- */
-
-  {
-    int opt = 1;
-    setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
-    fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
-  }
-
-  /* --- Bind it to the right port --- */
-
-  if (bind(fd, &ga->sa, ga->a.sz)) {
-    fw_log(-1, "[%s] couldn't bind to %s: %s", ss->s.desc, strerror(errno));
-    goto fail_1;
-  }
-  if (ga->a.ops->bound)
-    ga->a.ops->bound(&ga->a, ss->ao);
-
   /* --- Set it to listen for connections --- */
 
-  if (listen(fd, 5)) {
+  setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
+  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
+  if (listen(fd, ss->o.listen)) {
     fw_log(-1, "[%s] couldn't listen on socket: %s",
 	   ss->s.desc, strerror(errno));
     goto fail_1;
@@ -527,6 +563,7 @@ static void ssource_attach(source *s, scanner *sc, target *t)
 {
   ssource *ss = (ssource *)s;
   int fd;
+  int opt = 1;
 
   ss->t = t;
 
@@ -542,35 +579,23 @@ static void ssource_attach(source *s, scanner *sc, target *t)
     dstr_destroy(&d);
   }
 
-  /* --- Initialize the socket for listening --- */
-
-  {
-    gen_addr *ga = (gen_addr *)ss->a;
-
-    /* --- Make the socket --- */
-
-    if ((fd = socket(ga->a.ops->pf, SOCK_STREAM, 0)) < 0)
-      error(sc, "couldn't create socket: %s", strerror(errno));
-
-    /* --- Set it to allow address reuse --- */
+  /* --- Confirm the address --- */
 
-    {
-      int opt = 1;
-      setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
-      fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
-    }
+  if (ss->a->ops->confirm)
+    ss->a->ops->confirm(ss->a, ADDR_SRC, ss->ao);
 
-    /* --- Bind it to the right port --- */
+  /* --- Initialize the socket for listening --- */
 
-    if (bind(fd, &ga->sa, ga->a.sz))
-      error(sc, "couldn't bind to %s: %s", ss->s.desc, strerror(errno));
-    if (ga->a.ops->bound)
-      ga->a.ops->bound(&ga->a, ss->ao);
+  if ((fd = ss->a->ops->bind(ss->a, ss->ao)) < 0)
+    error(sc, "couldn't bind socket `%s': %s", ss->s.desc, strerror(errno));
 
-    /* --- Set it to listen for connections --- */
+  /* --- Set it to listen for connections --- */
 
-    if (listen(fd, 5))
-      error(sc, "couldn't listen on socket: %s", strerror(errno));
+  setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
+  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
+  if (listen(fd, ss->o.listen)) {
+    error(sc, "couldn't listen on socket `%s': %s",
+	  ss->s.desc, strerror(errno));
   }
 
   /* --- We're ready to go now --- */
@@ -587,17 +612,17 @@ static void ssource_destroy(source *s)
 {
   ssource *ss = (ssource *)s;
 
-  if (ss->o.conn) {
+  if (ss->o.conn || ss->o.opt != SOCKOPT_LIMIT) {
     sel_rmfile(&ss->r);
     close(ss->r.fd);
     if (ss->a->ops->unbind)
       ss->a->ops->unbind(ss->a);
   }
-  if (ss->a->ops->freeopts)
-    ss->a->ops->freeopts(ss->ao);
+  if (ss->a->ops->freesrcopts)
+    ss->a->ops->freesrcopts(ss->ao);
   else
     DESTROY(ss->ao);
-  /* free(ss->s.desc); */
+  xfree(ss->s.desc);
   ss->a->ops->destroy(ss->a);
   ss->t->ops->destroy(ss->t);
   source_remove(&ss->s);
@@ -614,6 +639,27 @@ source_ops ssource_ops = {
 
 /*----- Target definition -------------------------------------------------*/
 
+/* --- @options@ --- */
+
+static int starget_option(target *t, scanner *sc)
+{
+  starget *st = (starget *)t;
+
+  CONF_BEGIN(sc, "starget", "socket target")
+
+  /* --- Pass the option around the various address types --- */
+
+  if (st) {
+    if (st->a->ops->option && st->a->ops->option(sc, st->ao, ADDR_DEST))
+      CONF_ACCEPT;
+  }
+  /* We'd have done it already if it was global */
+
+  /* --- Done --- */
+
+  CONF_END;
+}
+
 /* --- @read@ --- */
 
 static target *starget_read(scanner *sc)
@@ -625,6 +671,11 @@ static target *starget_read(scanner *sc)
   st = CREATE(starget);
   st->t.ops = &starget_ops;
   st->a = getaddr(sc, ADDR_DEST);
+  if (st->a->ops->inittargopts)
+    st->ao = st->a->ops->inittargopts();
+  else
+    st->ao = CREATE(addr_opts);
+  *st->ao = gtao;
   dstr_puts(&d, "socket.");
   st->a->ops->print(st->a, ADDR_DEST, &d);
   st->t.desc = xstrdup(d.buf);
@@ -632,54 +683,33 @@ static target *starget_read(scanner *sc)
   return (&st->t);
 }
 
-/* --- @create@ --- *
- *
- * Arguments:	@target *t@ = pointer to target
- *		@const char *desc@ = description of connection
- *
- * Returns:	Pointer to a created endpoint.
- *
- * Use:		Generates a target endpoint for communication.
- */
+/* --- @confirm@ --- */
+
+static void starget_confirm(target *t)
+{
+  starget *st = (starget *)t;
+
+  if (st->a->ops->confirm)
+    st->a->ops->confirm(st->a, ADDR_DEST, st->ao);
+}
+
+/* --- @create@ --- */
 
 static endpt *starget_create(target *t, const char *desc)
 {
   starget *st = (starget *)t;
   stept *e = CREATE(stept);
-  int fd;
-  gen_addr *ga = (gen_addr *)st->a;
-  int opt;
 
-  if ((fd = socket(st->a->ops->pf, SOCK_STREAM, 0)) < 0)
-    return (0);
-  setsockopt(fd, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt));
-  fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
   e->e.ops = &stept_ops;
   e->e.other = 0;
-  e->e.f = EPF_FILE | SKF_CONN;
+  e->e.f = EPF_FILE | EPF_PENDING;
   e->e.t = 0;
-  e->desc = desc;
-
-  /* --- Pay attention --- *
-   *
-   * This bit is quite subtle.  The connect can succeed or fail later: that's
-   * fine.  The problem comes if it makes its mind up right now.  The flag
-   * @SKF_CONN@ signifies that I'm trying to connect.  I set it up to begin
-   * with and @stept_go@ turns it off when it's done: @stept_close@ uses it
-   * to decide whether to kill the connection.  The flag @EPF_PENDING@ is
-   * only set after @conn_init@ returns and @SKF_CONN@ is still set (meaning
-   * that the connection is still in progress).  That's used to let
-   * @stept_go@ know whether to kill the other endpoint.  The flag
-   * @SKF_BROKEN@ is used to signify an immediate failure.
-   */
-
-  conn_init(&e->c, sel, fd, &ga->sa, ga->a.sz, stept_go, e);
-  if (e->e.f & SKF_BROKEN) {
+  e->desc = xstrdup(desc);
+  if (st->a->ops->connect(st->a, st->ao, &e->c, &e->e)) {
+    fw_log(-1, "[%s] couldn't connect: %s", e->desc, strerror(errno));
     DESTROY(e);
     return (0);
   }
-  if (e->e.f & SKF_CONN)
-    e->e.f |= EPF_PENDING;
   fw_inc();
   return (&e->e);
 }
@@ -689,8 +719,12 @@ static endpt *starget_create(target *t, const char *desc)
 static void starget_destroy(target *t)
 {
   starget *st = (starget *)t;
+  if (st->a->ops->freetargopts)
+    st->a->ops->freetargopts(st->ao);
+  else
+    DESTROY(st->ao);
   st->a->ops->destroy(st->a);
-  /* free(st->t.desc); */
+  xfree(st->t.desc);
   DESTROY(st);
 }
 
@@ -698,7 +732,8 @@ static void starget_destroy(target *t)
 
 target_ops starget_ops = {
   "socket",
-  0, starget_read, starget_create, starget_destroy
+  starget_option, starget_read, starget_confirm,
+  starget_create, starget_destroy
 };
 
 /*----- That's all, folks -------------------------------------------------*/