From 9c3dbb02682e244c37bfc54da6bb98cbf241b643 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 3 Nov 2014 22:31:46 -0600 Subject: [PATCH] sd-dhcp-client: fix REBOOT state handling client->secs wasn't getting set in the REBOOT state, causing an assertion. REBOOT should work the same way as INIT, per RFC 2131: secs 2 Filled in by client, seconds elapsed since client began address acquisition or renewal process. REBOOT is necessary because many DHCP servers (especially on home routers) do not hand back the same IP address when in response to a DISCOVER packet, even if the same client ID is used. --- .../src/libsystemd-network/sd-dhcp-client.c | 33 +++++++++---------- 1 file changed, 15 insertions(+), 18 deletions(-) diff --git a/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-client.c b/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-client.c index a8ec6542a1..1a54d3abee 100644 --- a/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-client.c +++ b/src/dhcp-manager/systemd-dhcp/src/libsystemd-network/sd-dhcp-client.c @@ -89,7 +89,6 @@ struct sd_dhcp_client { uint32_t mtu; uint32_t xid; usec_t start_time; - uint16_t secs; unsigned int attempt; usec_t request_sent; sd_event_source *timeout_t1; @@ -399,15 +398,19 @@ static int client_message_init(sd_dhcp_client *client, DHCPPacket **ret, _cleanup_free_ DHCPPacket *packet; size_t optlen, optoffset, size; be16_t max_size; + usec_t time_now; + uint16_t secs; int r; assert(client); - assert(client->secs); + assert(client->start_time); assert(ret); assert(_optlen); assert(_optoffset); assert(type == DHCP_DISCOVER || type == DHCP_REQUEST); + /* See RFC2131 section 4.4.1 */ + optlen = DHCP_MIN_OPTIONS_SIZE; size = sizeof(DHCPPacket) + optlen; @@ -422,7 +425,15 @@ static int client_message_init(sd_dhcp_client *client, DHCPPacket **ret, /* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers refuse to issue an DHCP lease if 'secs' is set to zero */ - packet->dhcp.secs = htobe16(client->secs); + r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now); + if (r < 0) + return r; + assert(time_now >= client->start_time); + + /* seconds between sending first and last DISCOVER + * must always be strictly positive to deal with broken servers */ + secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1; + packet->dhcp.secs = htobe16(secs); /* RFC2132 section 4.1 A client that cannot receive unicast IP datagrams until its protocol @@ -529,24 +540,12 @@ static int dhcp_client_send_raw(sd_dhcp_client *client, DHCPPacket *packet, static int client_send_discover(sd_dhcp_client *client) { _cleanup_free_ DHCPPacket *discover = NULL; size_t optoffset, optlen; - usec_t time_now; int r; assert(client); assert(client->state == DHCP_STATE_INIT || client->state == DHCP_STATE_SELECTING); - /* See RFC2131 section 4.4.1 */ - - r = sd_event_now(client->event, clock_boottime_or_monotonic(), &time_now); - if (r < 0) - return r; - assert(time_now >= client->start_time); - - /* seconds between sending first and last DISCOVER - * must always be strictly positive to deal with broken servers */ - client->secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1; - r = client_message_init(client, &discover, DHCP_DISCOVER, &optlen, &optoffset); if (r < 0) @@ -963,10 +962,8 @@ static int client_start(sd_dhcp_client *client) { } client->fd = r; - if (client->state == DHCP_STATE_INIT) { + if (client->state == DHCP_STATE_INIT || client->state == DHCP_STATE_INIT_REBOOT) client->start_time = now(clock_boottime_or_monotonic()); - client->secs = 0; - } return client_initialize_events(client, client_receive_message_raw); }