diff options
| author | Lennart Poettering <lennart@poettering.net> | 2015-08-28 12:17:37 +0200 |
|---|---|---|
| committer | Lennart Poettering <lennart@poettering.net> | 2015-08-28 12:17:37 +0200 |
| commit | 776d6aac183a1f711b9ebd62558ce914328b03da (patch) | |
| tree | e8447fb2be457a8aba03fb30396df45c254bc0a5 | |
| parent | 84d449b55215dfe81305d3ee89606fdc17150ad6 (diff) | |
| parent | 83cedf7ae28925e37931e7e92d22be9c936a1def (diff) | |
Merge pull request #1067 from teg/dhcp-server
sd-dhcp-server: improve predictability of leases
| -rw-r--r-- | src/libsystemd-network/dhcp-server-internal.h | 1 | ||||
| -rw-r--r-- | src/libsystemd-network/sd-dhcp-server.c | 16 |
2 files changed, 13 insertions, 4 deletions
diff --git a/src/libsystemd-network/dhcp-server-internal.h b/src/libsystemd-network/dhcp-server-internal.h index 6cc794c937..268210fc50 100644 --- a/src/libsystemd-network/dhcp-server-internal.h +++ b/src/libsystemd-network/dhcp-server-internal.h @@ -59,7 +59,6 @@ struct sd_dhcp_server { be32_t netmask; be32_t pool_start; size_t pool_size; - size_t next_offer; char *timezone; diff --git a/src/libsystemd-network/sd-dhcp-server.c b/src/libsystemd-network/sd-dhcp-server.c index a46858258b..89b9a4c6be 100644 --- a/src/libsystemd-network/sd-dhcp-server.c +++ b/src/libsystemd-network/sd-dhcp-server.c @@ -669,6 +669,8 @@ static int get_pool_offset(sd_dhcp_server *server, be32_t requested_ip) { return be32toh(requested_ip) - be32toh(server->pool_start); } +#define HASH_KEY SD_ID128_MAKE(0d,1d,fe,bd,f1,24,bd,b3,47,f1,dd,6e,73,21,93,30) + int dhcp_server_handle_message(sd_dhcp_server *server, DHCPMessage *message, size_t length) { _cleanup_dhcp_request_free_ DHCPRequest *req = NULL; @@ -716,12 +718,20 @@ int dhcp_server_handle_message(sd_dhcp_server *server, DHCPMessage *message, if (existing_lease) address = existing_lease->address; else { + size_t next_offer; + + /* even with no persistence of leases, we try to offer the same client + the same IP address. we do this by using the hash of the client id + as the offset into the pool of leases when finding the next free one */ + + next_offer = client_id_hash_func(&req->client_id, HASH_KEY.bytes) % server->pool_size; + for (i = 0; i < server->pool_size; i++) { - if (!server->bound_leases[server->next_offer]) { - address = htobe32(be32toh(server->pool_start) + server->next_offer); + if (!server->bound_leases[next_offer]) { + address = htobe32(be32toh(server->pool_start) + next_offer); break; } else - server->next_offer = (server->next_offer + 1) % server->pool_size; + next_offer = (next_offer + 1) % server->pool_size; } } |