From: Roy Marples <roy@marples.name>
Date: Sun, 20 Apr 2008 19:02:19 +0000 (+0000)
Subject: We should send packets to a specific IP over the udp socket so we don't broadcast... 
X-Git-Tag: v4.0.2~467
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=35ff0dbb35b746c5594773ddc47516af440cdae7;p=thirdparty%2Fdhcpcd.git

We should send packets to a specific IP over the udp socket so we don't broadcast on layer 2 and unicast on layer 3, #64.
---

diff --git a/bpf.c b/bpf.c
index e419cb40..da75a315 100644
--- a/bpf.c
+++ b/bpf.c
@@ -122,8 +122,8 @@ eexit:
 }
 
 ssize_t
-send_packet(const struct interface *iface, int type,
-	    const unsigned char *data, ssize_t len)
+send_raw_packet(const struct interface *iface, int type,
+		const unsigned char *data, ssize_t len)
 {
 	struct iovec iov[2];
 	struct ether_header hw;
diff --git a/client.c b/client.c
index ae280230..48d17ac7 100644
--- a/client.c
+++ b/client.c
@@ -601,10 +601,12 @@ send_message(struct if_state *state, int type, const struct options *options)
 	struct dhcp_message *dhcp;
 	uint8_t *udp;
 	ssize_t len;
-	ssize_t retval;
+	ssize_t r;
 	struct in_addr from;
 	struct in_addr to;
 
+	logger(LOG_DEBUG, "sending %s with xid 0x%x",
+	       get_dhcp_op(type), state->xid);
 	state->last_type = type;
 	state->last_sent = uptime();
 	len = make_message(&dhcp, state->interface, &state->lease, state->xid,
@@ -614,15 +616,19 @@ send_message(struct if_state *state, int type, const struct options *options)
 		to.s_addr = state->lease.server.s_addr;
 	else
 		to.s_addr = 0;
-	len = make_udp_packet(&udp, (uint8_t *)dhcp, len, from, to);
-	free(dhcp);
-	logger(LOG_DEBUG, "sending %s with xid 0x%x",
-		get_dhcp_op(type), state->xid);
-	retval = send_packet(state->interface, ETHERTYPE_IP, udp, len);
-	if (retval == -1)
-		logger(LOG_ERR, "send_packet: %s", strerror(errno));
-	free(udp);
-	return retval;
+	if (to.s_addr) {
+		r = send_packet(state->interface, to, (uint8_t *)dhcp, len);
+		if (r == -1)
+			logger(LOG_ERR, "send_packet: %s", strerror(errno));
+	} else {
+		len = make_udp_packet(&udp, (uint8_t *)dhcp, len, from, to);
+		free(dhcp);
+		r = send_raw_packet(state->interface, ETHERTYPE_IP, udp, len);
+		if (r == -1)
+			logger(LOG_ERR, "send_raw_packet: %s", strerror(errno));
+		free(udp);
+	}
+	return r;
 }
 
 static void
@@ -809,7 +815,8 @@ handle_timeout(struct if_state *state, const struct options *options)
 
 		do_socket(state, SOCKET_CLOSED);
 
-		if (options->options & DHCPCD_INFORM)
+		if (options->options & DHCPCD_INFORM ||
+		    options->options & DHCPCD_TEST)
 			return -1;
 
 		if (state->options & DHCPCD_IPV4LL ||
diff --git a/dhcp.c b/dhcp.c
index ebd3284b..820f3dd5 100644
--- a/dhcp.c
+++ b/dhcp.c
@@ -696,8 +696,8 @@ make_message(struct dhcp_message **message,
 	     uint32_t xid, uint8_t type, const struct options *options)
 {
 	struct dhcp_message *dhcp;
-	uint8_t *m;
-	uint8_t *p;
+	uint8_t *d, *m, *p;
+	const char *c;
 	uint8_t *n_params = NULL;
 	size_t l;
 	time_t up = uptime() - iface->start_uptime;
@@ -826,8 +826,9 @@ make_message(struct dhcp_message **message,
 			} else {
 				/* Draft IETF DHC-FQDN option (81) */
 				*p++ = DHCP_FQDN;
-				*p++ = (l = strlen(options->hostname)) + 3;
-				/* Flags: 0000NEOS
+				*p++ = strlen(options->hostname) + 5;
+				/*
+				 * Flags: 0000NEOS
 				 * S: 1 => Client requests Server to update
 				 *         a RR in DNS as well as PTR
 				 * O: 1 => Server indicates to client that
@@ -836,11 +837,20 @@ make_message(struct dhcp_message **message,
 				 * N: 1 => Client requests Server to not
 				 *         update DNS
 				 */
-				*p++ = options->fqdn & 0x9;
+				*p++ = (options->fqdn & 0x9) | 0x4;
 				*p++ = 0; /* from server for PTR RR */
 				*p++ = 0; /* from server for A RR if S=1 */
-				memcpy(p, options->hostname, l);
-				p += l;
+				c = options->hostname;
+				d = p++;
+				while (*c) {
+					if (*c == '.') {
+						*d = p - d - 1;
+						d = p++;
+					} else
+						*p++ = (uint8_t) *c;
+					c++;
+				}
+				*p ++ = 0;
 			}
 		}
 
diff --git a/dhcpcd.8.in b/dhcpcd.8.in
index d187e8f8..8ff4f605 100644
--- a/dhcpcd.8.in
+++ b/dhcpcd.8.in
@@ -132,7 +132,9 @@ You can use this option to specify the
 sent, or an empty string to
 stop any
 .Ar hostname
-from being sent.
+from being sent. If
+.Ar hostname
+is an FQDN (ie, contains a .) then it will be encoded as such.
 .It Fl i , -classid Ar classid
 Override the DHCP vendor
 .Ar classid
diff --git a/dhcpcd.conf.5 b/dhcpcd.conf.5
index 9b95fba1..9befff3a 100644
--- a/dhcpcd.conf.5
+++ b/dhcpcd.conf.5
@@ -46,7 +46,14 @@ from the server. It can be a variable to be used in
 or the numerical value. You can specify more seperated by commas, spaces or
 more option lines.
 .It Ic hostname Ar name
-Sends specified hostname to the DHCP server so it can be registered in DNS.
+Sends specified
+.Ar hostname 
+o the DHCP server so it can be registered in DNS. If
+.Ar hostname
+if a FQDN (ie, contains a .) then it will be encoded a such.
+.It Ic fqdn Op none | ptr | both
+none disables FQDN encoding, ptr just asks the DHCP server to update the PTR
+record of the host in DNS whereas both also updates the A record.
 .It Ic leasetime Ar seconds
 Request a leasetime of
 .Ar seconds .
diff --git a/net.c b/net.c
index 10661956..467cdf7e 100644
--- a/net.c
+++ b/net.c
@@ -443,6 +443,23 @@ eexit:
         return -1;
 }
 
+ssize_t
+send_packet(const struct interface *iface, struct in_addr to,
+	    const uint8_t *data, ssize_t len)
+{
+	union sockunion {
+		struct sockaddr sa;
+		struct sockaddr_in sin;
+	} su;
+
+	memset(&su, 0, sizeof(su));
+	su.sin.sin_family = AF_INET;
+	su.sin.sin_addr.s_addr = to.s_addr;
+	su.sin.sin_port = htons(DHCP_SERVER_PORT);
+
+	return sendto(iface->udp_fd, data, len, 0, &su.sa, sizeof(su));
+}
+
 struct udp_dhcp_packet
 {
 	struct ip ip;
@@ -648,8 +665,8 @@ send_arp(const struct interface *iface, int op, struct in_addr sip,
 	}
 	memcpy(ar_tpa(arp), &tip, (size_t)arp->ar_pln);
 
-	retval = send_packet(iface, ETHERTYPE_ARP,
-			     (unsigned char *) arp, arphdr_len(arp));
+	retval = send_raw_packet(iface, ETHERTYPE_ARP,
+				 (uint8_t *)arp, arphdr_len(arp));
 	if (retval == -1)
 		logger(LOG_ERR,"send_packet: %s", strerror(errno));
 	free(arp);
diff --git a/net.h b/net.h
index d767a9ee..ef968e18 100644
--- a/net.h
+++ b/net.h
@@ -166,8 +166,10 @@ int valid_udp_packet(uint8_t *);
 void setup_packet_filters(void);
 #endif
 int open_socket(struct interface *, int);
-ssize_t send_packet(const struct interface *, int,
+ssize_t send_packet(const struct interface *, struct in_addr, 
 		    const uint8_t *, ssize_t);
+ssize_t send_raw_packet(const struct interface *, int,
+			const uint8_t *, ssize_t);
 ssize_t get_packet(const struct interface *, uint8_t *,
 		   uint8_t *, ssize_t *, ssize_t *);
 
diff --git a/socket.c b/socket.c
index 97a24be4..54d2706d 100644
--- a/socket.c
+++ b/socket.c
@@ -141,8 +141,8 @@ eexit:
 }
 
 ssize_t
-send_packet(const struct interface *iface, int type,
-	    const uint8_t *data, ssize_t len)
+send_raw_packet(const struct interface *iface, int type,
+		const uint8_t *data, ssize_t len)
 {
 	union sockunion {
 		struct sockaddr sa;
@@ -153,12 +153,10 @@ send_packet(const struct interface *iface, int type,
 	memset(&su, 0, sizeof(su));
 	su.sll.sll_family = AF_PACKET;
 	su.sll.sll_protocol = htons(type);
-
 	if (!(su.sll.sll_ifindex = if_nametoindex(iface->name))) {
 		errno = ENOENT;
 		return -1;
 	}
-
 	su.sll.sll_hatype = htons(iface->family);
 	su.sll.sll_halen = iface->hwlen;
 	if (iface->family == ARPHRD_INFINIBAND)
@@ -167,7 +165,7 @@ send_packet(const struct interface *iface, int type,
 	else
 		memset(&su.sll.sll_addr, 0xff, iface->hwlen);
 
-	return sendto(iface->fd, data, len,0,&su.sa,sizeof(su));
+	return sendto(iface->fd, data, len, 0, &su.sa, sizeof(su));
 }
 
 /* Linux has no need for the buffer as we can read as much as we want.