diff -up dhcp-4.3.4/client/dhclient.c.improved-xid dhcp-4.3.4/client/dhclient.c --- dhcp-4.3.4/client/dhclient.c.improved-xid 2016-04-29 12:54:55.997102182 +0200 +++ dhcp-4.3.4/client/dhclient.c 2016-04-29 12:57:25.123139587 +0200 @@ -1045,6 +1045,26 @@ main(int argc, char **argv) { } } + /* We create a backup seed before rediscovering interfaces in order to + have a seed built using all of the available interfaces + It's interesting if required interfaces doesn't let us defined + a really unique seed due to a lack of valid HW addr later + (this is the case with DHCP over IB) + We only use the last device as using a sum could broke the + uniqueness of the seed among multiple nodes + */ + unsigned backup_seed = 0; + for (ip = interfaces; ip; ip = ip -> next) { + int junk; + if ( ip -> hw_address.hlen <= sizeof seed ) + continue; + memcpy (&junk, + &ip -> hw_address.hbuf [ip -> hw_address.hlen - + sizeof seed], sizeof seed); + backup_seed = junk; + } + + /* At this point, all the interfaces that the script thinks are relevant should be running, so now we once again call discover_interfaces(), and this time ask it to actually set @@ -1059,14 +1079,36 @@ main(int argc, char **argv) { Not much entropy, but we're booting, so we're not likely to find anything better. */ seed = 0; + int seed_flag = 0; for (ip = interfaces; ip; ip = ip->next) { int junk; + if ( ip -> hw_address.hlen <= sizeof seed ) + continue; memcpy(&junk, &ip->hw_address.hbuf[ip->hw_address.hlen - sizeof seed], sizeof seed); seed += junk; + seed_flag = 1; } - srandom(seed + cur_time + (unsigned)getpid()); + if ( seed_flag == 0 ) { + if ( backup_seed != 0 ) { + seed = backup_seed; + log_info ("xid: rand init seed (0x%x) built using all" + " available interfaces",seed); + } + else { + seed = cur_time^((unsigned) gethostid()) ; + log_info ("xid: warning: no netdev with useable HWADDR found" + " for seed's uniqueness enforcement"); + log_info ("xid: rand init seed (0x%x) built using gethostid", + seed); + } + /* we only use seed and no current time as a broadcast reply */ + /* will certainly be used by the hwaddrless interface */ + srandom(seed + ((unsigned)(cur_tv.tv_usec * 1000000)) + (unsigned)getpid()); + } + else + srandom(seed + ((unsigned)(cur_tv.tv_usec * 1000000)) + (unsigned)getpid()); /* Setup specific Infiniband options */ for (ip = interfaces; ip; ip = ip->next) { @@ -1633,7 +1675,7 @@ void dhcpack (packet) return; } - log_info ("DHCPACK from %s", piaddr (packet -> client_addr)); + log_info ("DHCPACK from %s (xid=0x%x)", piaddr (packet -> client_addr), ntohl(client -> xid)); lease = packet_to_lease (packet, client); if (!lease) { @@ -2541,7 +2583,7 @@ void dhcpnak (packet) return; } - log_info ("DHCPNAK from %s", piaddr (packet -> client_addr)); + log_info ("DHCPNAK from %s (xid=0x%x)", piaddr (packet -> client_addr), ntohl(client -> xid)); if (!client -> active) { #if defined (DEBUG) @@ -2674,10 +2716,10 @@ void send_discover (cpp) (long)(client -> interval)); } else #endif - log_info ("DHCPDISCOVER on %s to %s port %d interval %ld", + log_info ("DHCPDISCOVER on %s to %s port %d interval %ld (xid=0x%x)", client -> name ? client -> name : client -> interface -> name, inet_ntoa (sockaddr_broadcast.sin_addr), - ntohs (sockaddr_broadcast.sin_port), (long)(client -> interval)); + ntohs (sockaddr_broadcast.sin_port), (long)(client -> interval), ntohl(client -> xid)); /* Send out a packet. */ #if defined(DHCPv6) && defined(DHCP4o6) @@ -2962,10 +3004,10 @@ void send_request (cpp) log_info ("DHCPREQUEST"); } else #endif - log_info ("DHCPREQUEST on %s to %s port %d", + log_info ("DHCPREQUEST on %s to %s port %d (xid=0x%x)", client -> name ? client -> name : client -> interface -> name, inet_ntoa (destination.sin_addr), - ntohs (destination.sin_port)); + ntohs (destination.sin_port), ntohl(client -> xid)); #if defined(DHCPv6) && defined(DHCP4o6) if (dhcpv4_over_dhcpv6) { @@ -3022,10 +3064,10 @@ void send_decline (cpp) log_info ("DHCPDECLINE"); } else #endif - log_info ("DHCPDECLINE on %s to %s port %d", + log_info ("DHCPDECLINE on %s to %s port %d (xid=0x%x)", client->name ? client->name : client->interface->name, inet_ntoa(sockaddr_broadcast.sin_addr), - ntohs(sockaddr_broadcast.sin_port)); + ntohs(sockaddr_broadcast.sin_port), ntohl(client -> xid)); /* Send out a packet. */ #if defined(DHCPv6) && defined(DHCP4o6) @@ -3084,10 +3126,10 @@ void send_release (cpp) log_info ("DHCPRELEASE"); } else #endif - log_info ("DHCPRELEASE on %s to %s port %d", + log_info ("DHCPRELEASE on %s to %s port %d (xid=0x%x)", client -> name ? client -> name : client -> interface -> name, inet_ntoa (destination.sin_addr), - ntohs (destination.sin_port)); + ntohs (destination.sin_port), ntohl(client -> xid)); #if defined(DHCPv6) && defined(DHCP4o6) if (dhcpv4_over_dhcpv6) {