From: Roy Marples <roy@marples.name>
Date: Fri, 30 Apr 2010 03:03:23 +0000 (+0000)
Subject: Improve log_dhcp to always tell from which server a message came.
X-Git-Tag: v5.2.3~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5f31d875b11f52810faf2bc55093578e16ea4b84;p=thirdparty%2Fdhcpcd.git

Improve log_dhcp to always tell from which server a message came.

Currently this information is derived from the DHO_SERVERID option.
But when the server doesn't set it, no source info is logged. Print
the src ip of the udp packet as "from" in this case. This is not perfect
as there could be a dhcp forwarder involved, but this is better than nothing.

Thanks to Gerd von Egidy.
---

diff --git a/dhcpcd.c b/dhcpcd.c
index 983c3b64..bc239340 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -407,7 +407,7 @@ start_expire(void *arg)
 
 static void
 log_dhcp(int lvl, const char *msg,
-    const struct interface *iface, const struct dhcp_message *dhcp)
+    const struct interface *iface, const struct dhcp_message *dhcp, const struct in_addr *from)
 {
 	char *a;
 	struct in_addr addr;
@@ -432,9 +432,9 @@ log_dhcp(int lvl, const char *msg,
 			syslog(lvl, "%s: %s %s from %s",
 			    iface->name, msg, a, inet_ntoa(addr));
 	} else if (a != NULL)
-		syslog(lvl, "%s: %s %s", iface->name, msg, a);
+		syslog(lvl, "%s: %s %s from %s", iface->name, msg, a, inet_ntoa(*from));
 	else
-		syslog(lvl, "%s: %s", iface->name, msg);
+		syslog(lvl, "%s: %s from %s", iface->name, msg, inet_ntoa(*from));
 	free(a);
 }
 
@@ -463,7 +463,7 @@ whitelisted_ip(const struct if_options *ifo, in_addr_t addr)
 }
 
 static void
-handle_dhcp(struct interface *iface, struct dhcp_message **dhcpp)
+handle_dhcp(struct interface *iface, struct dhcp_message **dhcpp, const struct in_addr *from)
 {
 	struct if_state *state = iface->state;
 	struct if_options *ifo = state->options;
@@ -485,11 +485,11 @@ handle_dhcp(struct interface *iface, struct dhcp_message **dhcpp)
 		if (has_option_mask(ifo->requiremask, DHO_SERVERID) &&
 		    get_option_addr(&addr, dhcp, DHO_SERVERID) == -1)
 		{
-			log_dhcp(LOG_WARNING, "reject NAK", iface, dhcp);
+			log_dhcp(LOG_WARNING, "reject NAK", iface, dhcp, from);
 			return;
 		}
 		/* We should restart on a NAK */
-		log_dhcp(LOG_WARNING, "NAK:", iface, dhcp);
+		log_dhcp(LOG_WARNING, "NAK:", iface, dhcp, from);
 		if (!(options & DHCPCD_TEST)) {
 			drop_config(iface, "NAK");
 			unlink(iface->leasefile);
@@ -512,7 +512,7 @@ handle_dhcp(struct interface *iface, struct dhcp_message **dhcpp)
 			 * To ignore bootp, require dhcp_message_type instead. */
 			if (type == 0 && i == DHO_SERVERID)
 				continue;
-			log_dhcp(LOG_WARNING, "reject DHCP", iface, dhcp);
+			log_dhcp(LOG_WARNING, "reject DHCP", iface, dhcp, from);
 			return;
 		}
 	}		
@@ -529,7 +529,7 @@ handle_dhcp(struct interface *iface, struct dhcp_message **dhcpp)
 		if (type == 0 ||
 		    get_option_addr(&lease->server, dhcp, DHO_SERVERID) != 0)
 			lease->server.s_addr = INADDR_ANY;
-		log_dhcp(LOG_INFO, "offered", iface, dhcp);
+		log_dhcp(LOG_INFO, "offered", iface, dhcp, from);
 		free(state->offer);
 		state->offer = dhcp;
 		*dhcpp = NULL;
@@ -558,18 +558,18 @@ handle_dhcp(struct interface *iface, struct dhcp_message **dhcpp)
 
 	if (type) {
 		if (type == DHCP_OFFER) {
-			log_dhcp(LOG_INFO, "ignoring offer of", iface, dhcp);
+			log_dhcp(LOG_INFO, "ignoring offer of", iface, dhcp, from);
 			return;
 		}
 
 		/* We should only be dealing with acks */
 		if (type != DHCP_ACK) {
-			log_dhcp(LOG_ERR, "not ACK or OFFER", iface, dhcp);
+			log_dhcp(LOG_ERR, "not ACK or OFFER", iface, dhcp, from);
 			return;
 		}
 
 		if (!(ifo->options & DHCPCD_INFORM))
-			log_dhcp(LOG_INFO, "acknowledged", iface, dhcp);
+			log_dhcp(LOG_INFO, "acknowledged", iface, dhcp, from);
 	}
 
 	/* BOOTP could have already assigned this above, so check we still
@@ -685,7 +685,7 @@ handle_dhcp_packet(void *arg)
 			    hwaddr_ntoa(dhcp->chaddr, sizeof(dhcp->chaddr)));
 			continue;
 		}
-		handle_dhcp(iface, &dhcp);
+		handle_dhcp(iface, &dhcp, &from);
 		if (iface->raw_fd == -1)
 			break;
 	}