Re: [systemd-devel] [PATCH] sd-dhcp-client: fix REBOOT state handling
On Tue, 2014-11-18 at 18:41 +0100, Tom Gundersen wrote: (but cc'ing Patrik just to make sure) RFC 2131: secs 2 Filled in by client, seconds elapsed since client began address acquisition or renewal process. @@ -422,7 +423,15 @@ 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); The previous code assumed that resending a message mean really sending an identical one in place of the lost one. This change actually nags on the other end that time has really passed, be it a clue to a DHCP relay that it should do something else than before. Looking at the RFC snippet and the patch, I think this is what the RFC actually tried to say. Cheers, Patrik ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] sd-dhcp-client: fix REBOOT state handling
On Tue, 2014-11-04 at 11:20 -0600, Dan Williams wrote: 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 some DHCP servers (eg on home routers) do not hand back the same IP address unless the 'ciaddr' field is filled with that address, which DISCOVER cannot do per the RFCs. This leads to multiple leases on machine reboot or DHCP client restart. Anyone had a chance to review this patch? --- src/libsystemd-network/sd-dhcp-client.c | 31 +-- 1 file changed, 13 insertions(+), 18 deletions(-) diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index a8ec654..300fc38 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/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; @@ -399,10 +398,12 @@ 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); @@ -422,7 +423,15 @@ 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 +538,12 @@ 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 +960,8 @@ 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); } ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] sd-dhcp-client: fix REBOOT state handling
Applied. Thanks! (but cc'ing Patrik just to make sure) On Tue, Nov 4, 2014 at 6:20 PM, Dan Williams d...@redhat.com wrote: 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 some DHCP servers (eg on home routers) do not hand back the same IP address unless the 'ciaddr' field is filled with that address, which DISCOVER cannot do per the RFCs. This leads to multiple leases on machine reboot or DHCP client restart. --- src/libsystemd-network/sd-dhcp-client.c | 31 +-- 1 file changed, 13 insertions(+), 18 deletions(-) diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index a8ec654..300fc38 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/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; @@ -399,10 +398,12 @@ 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); @@ -422,7 +423,15 @@ 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 +538,12 @@ 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 +960,8 @@ 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); } -- 1.9.3 ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] [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 some DHCP servers (eg on home routers) do not hand back the same IP address unless the 'ciaddr' field is filled with that address, which DISCOVER cannot do per the RFCs. This leads to multiple leases on machine reboot or DHCP client restart. --- src/libsystemd-network/sd-dhcp-client.c | 31 +-- 1 file changed, 13 insertions(+), 18 deletions(-) diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index a8ec654..300fc38 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/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; @@ -399,10 +398,12 @@ 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); @@ -422,7 +423,15 @@ 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 +538,12 @@ 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 +960,8 @@ 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); } -- 1.9.3 ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel