Merge pull request #297 from mjeveritt/patch-11-test-pr

pppd: Add option to ask peer for WINS address

This adds a 'usepeerwins' option, analogous to the usepeerdns option,
to ask the peer for WINS server addresses.  Nothing is done with
the addresses provided other than to pass them to the ip-up
script in environment variables.

With this, if the peer sends an IPCP Configure-NAK containing
WINS addresses, we will request them in the following IPCP
Configure-Request.

Co-authored-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Michael Everitt <gentoo@veremit.xyz>
Signed-off-by: Lars Wendler <polynomial-c@gentoo.org>
Signed-off-by: Michael Everitt <michael@2e0cer.net>

3 files changed, 92 insertions, 23 deletions

diff --git a/pppd/ipcp.c b/pppd/ipcp.c
index 6bcdf74..0dc251e 100644
--- a/pppd/ipcp.c
+++ b/pppd/ipcp.c
@@ -93,6 +93,7 @@ struct notifier *ip_down_notifier = NULL;
 static int default_route_set[NUM_PPP];	/* Have set up a default route */
 static int proxy_arp_set[NUM_PPP];	/* Have created proxy arp entry */
 static bool usepeerdns;			/* Ask peer for DNS addrs */
+static bool usepeerwins;		/* Ask peer for WINS addrs */
 static int ipcp_is_up;			/* have called np_up() */
 static int ipcp_is_open;		/* haven't called np_finished() */
 static bool ask_for_local;		/* request our address from peer */
@@ -221,6 +222,9 @@ static option_t ipcp_option_list[] = {
     { "usepeerdns", o_bool, &usepeerdns,
       "Ask peer for DNS address(es)", 1 },
 
+    { "usepeerwins", o_bool, &usepeerwins,
+      "Ask peer for WINS address(es)", 1 },
+
     { "netmask", o_special, (void *)setnetmask,
       "set netmask", OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, netmask_str },
 
@@ -691,6 +695,8 @@ ipcp_resetci(fsm *f)
 	wo->accept_remote = 1;
     wo->req_dns1 = usepeerdns;	/* Request DNS addresses from the peer */
     wo->req_dns2 = usepeerdns;
+    wo->req_wins1 = usepeerwins; /* Request WINS addresses from the peer */
+    wo->req_wins2 = usepeerwins;
     *go = *wo;
     if (!ask_for_local)
 	go->ouraddr = 0;
@@ -742,8 +748,8 @@ ipcp_cilen(fsm *f)
 	    LENCIADDR(go->neg_addr) +
 	    LENCIDNS(go->req_dns1) +
 	    LENCIDNS(go->req_dns2) +
-	    LENCIWINS(go->winsaddr[0]) +
-	    LENCIWINS(go->winsaddr[1])) ;
+	    LENCIWINS(go->req_wins1) +
+	    LENCIWINS(go->req_wins2)) ;
 }
 
 
@@ -814,8 +820,8 @@ ipcp_addci(fsm *f, u_char *ucp, int *lenp)
 	    neg = 0; \
     }
 
-#define ADDCIWINS(opt, addr) \
-    if (addr) { \
+#define ADDCIWINS(opt, neg, addr) \
+    if (neg) { \
 	if (len >= CILEN_ADDR) { \
 	    u_int32_t l; \
 	    PUTCHAR(opt, ucp); \
@@ -824,7 +830,7 @@ ipcp_addci(fsm *f, u_char *ucp, int *lenp)
 	    PUTLONG(l, ucp); \
 	    len -= CILEN_ADDR; \
 	} else \
-	    addr = 0; \
+	    neg = 0; \
     }
 
     ADDCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs, go->ouraddr,
@@ -839,9 +845,9 @@ ipcp_addci(fsm *f, u_char *ucp, int *lenp)
 
     ADDCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
 
-    ADDCIWINS(CI_MS_WINS1, go->winsaddr[0]);
+    ADDCIWINS(CI_MS_WINS1, go->req_wins1, go->winsaddr[0]);
 
-    ADDCIWINS(CI_MS_WINS2, go->winsaddr[1]);
+    ADDCIWINS(CI_MS_WINS2, go->req_wins2, go->winsaddr[1]);
     
     *lenp -= len;
 }
@@ -943,8 +949,8 @@ ipcp_ackci(fsm *f, u_char *p, int len)
 	    goto bad; \
     }
 
-#define ACKCIWINS(opt, addr) \
-    if (addr) { \
+#define ACKCIWINS(opt, neg, addr) \
+    if (neg) { \
 	u_int32_t l; \
 	if ((len -= CILEN_ADDR) < 0) \
 	    goto bad; \
@@ -970,9 +976,9 @@ ipcp_ackci(fsm *f, u_char *p, int len)
 
     ACKCIDNS(CI_MS_DNS2, go->req_dns2, go->dnsaddr[1]);
 
-    ACKCIWINS(CI_MS_WINS1, go->winsaddr[0]);
+    ACKCIWINS(CI_MS_WINS1, go->req_wins1, go->winsaddr[0]);
 
-    ACKCIWINS(CI_MS_WINS2, go->winsaddr[1]);
+    ACKCIWINS(CI_MS_WINS2, go->req_wins2, go->winsaddr[1]);
 
     /*
      * If there are any remaining CIs, then this packet is bad.
@@ -1004,7 +1010,7 @@ ipcp_nakci(fsm *f, u_char *p, int len, int treat_as_reject)
     u_char cimaxslotindex, cicflag;
     u_char citype, cilen, *next;
     u_short cishort;
-    u_int32_t ciaddr1, ciaddr2, l, cidnsaddr;
+    u_int32_t ciaddr1, ciaddr2, l, cidnsaddr, ciwinsaddr;
     ipcp_options no;		/* options we've seen Naks for */
     ipcp_options try;		/* options to request next time */
 
@@ -1069,6 +1075,19 @@ ipcp_nakci(fsm *f, u_char *p, int len, int treat_as_reject)
 	code \
     }
 
+#define NAKCIWINS(opt, neg, code) \
+    if (go->neg && \
+	((cilen = p[1]) == CILEN_ADDR) && \
+	len >= cilen && \
+	p[0] == opt) { \
+	len -= cilen; \
+	INCPTR(2, p); \
+	GETLONG(l, p); \
+	ciwinsaddr = htonl(l); \
+	no.neg = 1; \
+	code \
+    }
+
     /*
      * Accept the peer's idea of {our,his} address, if different
      * from our idea, only if the accept_{local,remote} flag is set.
@@ -1145,6 +1164,22 @@ ipcp_nakci(fsm *f, u_char *p, int len, int treat_as_reject)
 	     }
 	     );
 
+    NAKCIWINS(CI_MS_WINS1, req_wins1,
+	     if (treat_as_reject) {
+		 try.req_wins1 = 0;
+	     } else {
+		 try.winsaddr[0] = ciwinsaddr;
+	     }
+	     );
+
+    NAKCIWINS(CI_MS_WINS2, req_wins2,
+	     if (treat_as_reject) {
+		 try.req_wins2 = 0;
+	     } else {
+		 try.winsaddr[1] = ciwinsaddr;
+	     }
+	     );
+
     /*
      * There may be remaining CIs, if the peer is requesting negotiation
      * on an option that we didn't include in our request packet.
@@ -1211,13 +1246,20 @@ ipcp_nakci(fsm *f, u_char *p, int len, int treat_as_reject)
 	    no.req_dns2 = 1;
 	    break;
 	case CI_MS_WINS1:
+	    if (go->req_wins1 || no.req_wins1 || cilen != CILEN_ADDR)
+		goto bad;
+	    GETLONG(l, p);
+	    try.winsaddr[0] = htonl(l);
+	    try.req_wins1 = 1;
+	    no.req_wins1 = 1;
+	    break;
 	case CI_MS_WINS2:
-	    if (cilen != CILEN_ADDR)
+	    if (go->req_wins2 || no.req_wins2 || cilen != CILEN_ADDR)
 		goto bad;
 	    GETLONG(l, p);
-	    ciaddr1 = htonl(l);
-	    if (ciaddr1)
-		try.winsaddr[citype == CI_MS_WINS2] = ciaddr1;
+	    try.winsaddr[1] = htonl(l);
+	    try.req_wins2 = 1;
+	    no.req_wins2 = 1;
 	    break;
 	}
 	p = next;
@@ -1237,7 +1279,6 @@ bad:
     return 0;
 }
 
-
 /*
  * ipcp_rejci - Reject some of our CIs.
  * Callback from fsm_rconfnakrej.
@@ -1332,8 +1373,8 @@ ipcp_rejci(fsm *f, u_char *p, int len)
 	try.neg = 0; \
     }
 
-#define REJCIWINS(opt, addr) \
-    if (addr && \
+#define REJCIWINS(opt, neg, addr) \
+    if (go->neg && \
 	((cilen = p[1]) == CILEN_ADDR) && \
 	len >= cilen && \
 	p[0] == opt) { \
@@ -1345,7 +1386,7 @@ ipcp_rejci(fsm *f, u_char *p, int len)
 	/* Check rejected value. */ \
 	if (cilong != addr) \
 	    goto bad; \
-	try.winsaddr[opt == CI_MS_WINS2] = 0; \
+	try.neg = 0; \
     }
 
     REJCIADDRS(CI_ADDRS, !go->neg_addr && go->old_addrs,
@@ -1360,9 +1401,9 @@ ipcp_rejci(fsm *f, u_char *p, int len)
 
     REJCIDNS(CI_MS_DNS2, req_dns2, go->dnsaddr[1]);
 
-    REJCIWINS(CI_MS_WINS1, go->winsaddr[0]);
+    REJCIWINS(CI_MS_WINS1, req_wins1, go->winsaddr[0]);
 
-    REJCIWINS(CI_MS_WINS2, go->winsaddr[1]);
+    REJCIWINS(CI_MS_WINS2, req_wins2, go->winsaddr[1]);
 
     /*
      * If there are any remaining CIs, then this packet is bad.
@@ -1552,7 +1593,7 @@ ipcp_reqci(fsm *f, u_char *inp,	int *len, int reject_if_disagree)
 	    /* Microsoft primary or secondary WINS request */
 	    d = citype == CI_MS_WINS2;
 
-	    /* If we do not have a DNS address then we cannot send it */
+	    /* If we do not have a WINS address then we cannot send it */
 	    if (ao->winsaddr[d] == 0 ||
 		cilen != CILEN_ADDR) {	/* Check CI length */
 		orc = CONFREJ;		/* Reject CI */
@@ -1808,6 +1849,13 @@ ipcp_up(fsm *f)
 	create_resolv(go->dnsaddr[0], go->dnsaddr[1]);
     }
 
+    if (go->winsaddr[0])
+        script_setenv("WINS1", ip_ntoa(go->winsaddr[0]), 0);
+    if (go->winsaddr[1])
+        script_setenv("WINS2", ip_ntoa(go->winsaddr[1]), 0);
+    if (usepeerwins && (go->winsaddr[0] || go->winsaddr[1]))
+        script_setenv("USEPEERWINS", "1", 0);
+
     /*
      * Check that the peer is allowed to use the IP address it wants.
      */
diff --git a/pppd/ipcp.h b/pppd/ipcp.h
index 52d2b22..90336c4 100644
--- a/pppd/ipcp.h
+++ b/pppd/ipcp.h
@@ -77,6 +77,8 @@ typedef struct ipcp_options {
     bool accept_remote;		/* accept peer's value for hisaddr */
     bool req_dns1;		/* Ask peer to send primary DNS address? */
     bool req_dns2;		/* Ask peer to send secondary DNS address? */
+    bool req_wins1;		/* Ask peer to send primary WINS address? */
+    bool req_wins2;		/* Ask peer to send secondary WINS address? */
     int  vj_protocol;		/* protocol value to use in VJ option */
     int  maxslotindex;		/* values for RFC1332 VJ compression neg. */
     bool cflag;
diff --git a/pppd/pppd.8 b/pppd/pppd.8
index b007406..7417a36 100644
--- a/pppd/pppd.8
+++ b/pppd/pppd.8
@@ -1240,6 +1240,16 @@ USEPEERDNS will be set to 1.  In addition, pppd will create an
 /etc/ppp/resolv.conf file containing one or two nameserver lines with
 the address(es) supplied by the peer.
 .TP
+.B usepeerwins
+Ask the peer for up to 2 WINS server addresses.  The addresses supplied
+by the peer (if any) are passed to the /etc/ppp/ip\-up script in the
+environment variables WINS1 and WINS2, and the environment variable
+USEPEERWINS will be set to 1.
+.LP
+Please note that some modems (like the Huawei E220) requires this option in
+order to avoid a race condition that results in the incorrect DNS servers
+being assigned.
+.TP
 .B user \fIname
 Sets the name used for authenticating the local system to the peer to
 \fIname\fR.
@@ -1842,6 +1852,15 @@ option was given).
 If the peer supplies DNS server addresses, this variable is set to the
 second DNS server address supplied (whether or not the usepeerdns
 option was given).
+.TP
+.B WINS1
+If the peer supplies WINS server addresses, this variable is set to the
+first WINS server address supplied.
+.TP
+.B WINS2
+If the peer supplies WINS server addresses, this variable is set to the
+second WINS server address supplied.
+.P
 .P
 Pppd invokes the following scripts, if they exist.  It is not an error
 if they don't exist.