X-Git-Url: https://git.ozlabs.org/?p=ppp.git;a=blobdiff_plain;f=pppd%2Fmultilink.c;h=c3a782f284662df0fce296d1e83518bd9a654f5f;hp=7a8165945e875aedc70202d8f73c99510987fa4e;hb=cffe80dd87a8ba3fba8f56fda45d2c0cfd62ba4d;hpb=7f804a990ae237a2ec2d53439258642df27df974

diff --git a/pppd/multilink.c b/pppd/multilink.c
index 7a81659..c3a782f 100644
--- a/pppd/multilink.c
+++ b/pppd/multilink.c
@@ -17,6 +17,8 @@
 #include <ctype.h>
 #include <stdlib.h>
 #include <netdb.h>
+#include <errno.h>
+#include <signal.h>
 #include <netinet/in.h>
 
 #include "pppd.h"
@@ -31,6 +33,8 @@ extern TDB_CONTEXT *pppdb;
 extern char db_key[];
 
 static int get_default_epdisc __P((struct epdisc *));
+static int parse_num __P((char *str, const char *key, int *valp));
+static int owns_unit __P((TDB_DATA pid, int unit));
 
 #define set_ip_epdisc(ep, addr) do {	\
 	ep->length = 4;			\
@@ -45,6 +49,8 @@ static int get_default_epdisc __P((struct epdisc *));
 	 || ((addr) & 0xfff00000) == 0xac100000		/* 172.16.x.x */  \
 	 || ((addr) & 0xffff0000) == 0xc0a80000)	/* 192.168.x.x */
 
+#define process_exists(n)	(kill((n), 0) == 0 || errno != ESRCH)
+
 void
 mp_check_options()
 {
@@ -66,8 +72,8 @@ mp_check_options()
 		/* get a default endpoint value */
 		wo->neg_endpoint = get_default_epdisc(&wo->endpoint);
 		if (wo->neg_endpoint)
-			info("using default endpoint %s",
-			     epdisc_to_str(&wo->endpoint));
+			dbglog("using default endpoint %s",
+			       epdisc_to_str(&wo->endpoint));
 	}
 }
 
@@ -80,17 +86,27 @@ mp_join_bundle()
 {
 	lcp_options *go = &lcp_gotoptions[0];
 	lcp_options *ho = &lcp_hisoptions[0];
-	int unit;
-	int i, l;
-	char *p, *endp;
+	lcp_options *ao = &lcp_allowoptions[0];
+	int unit, pppd_pid;
+	int l, mtu;
+	char *p;
 	TDB_DATA key, pid, rec;
 
 	if (!go->neg_mrru || !ho->neg_mrru) {
 		/* not doing multilink */
 		if (go->neg_mrru)
 			notice("oops, multilink negotiated only for receive");
-		multilink = 0;
+		mtu = ho->neg_mru? ho->mru: PPP_MRU;
+		if (mtu > ao->mru)
+			mtu = ao->mru;
+		if (demand) {
+			/* already have a bundle */
+			cfg_bundle(0, 0, 0, 0);
+			netif_set_mtu(0, mtu);
+			return 0;
+		}
 		make_new_bundle(0, 0, 0, 0);
+		netif_set_mtu(0, mtu);
 		set_ifunit(1);
 		return 0;
 	}
@@ -119,27 +135,38 @@ mp_join_bundle()
 			      epdisc_to_str(&ho->endpoint));
 	if (bundle_name)
 		p += slprintf(p, bundle_id+l-p, "/%v", bundle_name);
-	info("bundle_id = %s", bundle_id+7);
+
+	/*
+	 * For demand mode, we only need to configure the bundle
+	 * and attach the link.
+	 */
+	mtu = MIN(ho->mrru, ao->mru);
+	if (demand) {
+		cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
+		netif_set_mtu(0, mtu);
+		script_setenv("BUNDLE", bundle_id + 7, 1);
+		return 0;
+	}
 
 	/*
 	 * Check if the bundle ID is already in the database.
 	 */
 	unit = -1;
+	tdb_writelock(pppdb);
 	key.dptr = bundle_id;
 	key.dsize = p - bundle_id;
 	pid = tdb_fetch(pppdb, key);
 	if (pid.dptr != NULL) {
-		/* bundle ID exists, see if the pppd record still exists */
+		/* bundle ID exists, see if the pppd record exists */
 		rec = tdb_fetch(pppdb, pid);
 		if (rec.dptr != NULL) {
 			/* it is, parse the interface number */
-			p = strstr(rec.dptr, "IFNAME=ppp");
-			if (p != 0) {
-				p += 10;	/* skip to unit number */
-				i = strtol(p, &endp, 10);
-				if (endp != p && (*endp == 0 || *endp == ';'))
-					unit = i;
-			}
+			parse_num(rec.dptr, "IFNAME=ppp", &unit);
+			/* check the pid value */
+			if (!parse_num(rec.dptr, "PPPD_PID=", &pppd_pid)
+			    || !process_exists(pppd_pid)
+			    || !owns_unit(pid, unit))
+				unit = -1;
 			free(rec.dptr);
 		}
 		free(pid.dptr);
@@ -148,9 +175,10 @@ mp_join_bundle()
 	if (unit >= 0) {
 		/* attach to existing unit */
 		if (bundle_attach(unit)) {
-			info("attached link to interface %d", ifunit);
 			set_ifunit(0);
 			script_setenv("BUNDLE", bundle_id + 7, 0);
+			tdb_writeunlock(pppdb);
+			info("Link attached to %s", ifname);
 			return 1;
 		}
 		/* attach failed because bundle doesn't exist */
@@ -158,11 +186,59 @@ mp_join_bundle()
 
 	/* we have to make a new bundle */
 	make_new_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
+	netif_set_mtu(0, mtu);
 	set_ifunit(1);
 	script_setenv("BUNDLE", bundle_id + 7, 1);
+	tdb_writeunlock(pppdb);
+	info("New bundle %s created", ifname);
 	return 0;
 }
 
+static int
+parse_num(str, key, valp)
+     char *str;
+     const char *key;
+     int *valp;
+{
+	char *p, *endp;
+	int i;
+
+	p = strstr(str, key);
+	if (p != 0) {
+		p += strlen(key);
+		i = strtol(p, &endp, 10);
+		if (endp != p && (*endp == 0 || *endp == ';')) {
+			*valp = i;
+			return 1;
+		}
+	}
+	return 0;
+}
+
+/*
+ * Check whether the pppd identified by `key' still owns ppp unit `unit'.
+ */
+static int
+owns_unit(key, unit)
+     TDB_DATA key;
+     int unit;
+{
+	char ifkey[32];
+	TDB_DATA kd, vd;
+	int ret = 0;
+
+	slprintf(ifkey, sizeof(ifkey), "IFNAME=ppp%d", unit);
+	kd.dptr = ifkey;
+	kd.dsize = strlen(ifkey);
+	vd = tdb_fetch(pppdb, kd);
+	if (vd.dptr != NULL) {
+		ret = vd.dsize == key.dsize
+			&& memcmp(vd.dptr, key.dptr, vd.dsize) == 0;
+		free(vd.dptr);
+	}
+	return ret;
+}
+
 static int
 get_default_epdisc(ep)
      struct epdisc *ep;
@@ -292,12 +368,10 @@ str_to_epdisc(ep, str)
 		if (i == 0 || str[i] != 0)
 			return 0;
 		set_ip_epdisc(ep, addr);
-		dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
 		return 1;
 	}
 	if (i == EPD_MAC && get_if_hwaddr(ep->value, str) >= 0) {
 		ep->length = 6;
-		dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
 		return 1;
 	}
 
@@ -320,6 +394,6 @@ str_to_epdisc(ep, str)
 	if (*str != 0 || (ep->class == EPD_MAC && l != 6))
 		return 0;
 	ep->length = l;
-	dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
 	return 1;
 }
+