diff options
| -rw-r--r-- | src/libsystemd-network/sd-dhcp-client.c | 157 |
1 files changed, 98 insertions, 59 deletions
diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index 6e35ef403b..aff4c21e95 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/src/libsystemd-network/sd-dhcp-client.c @@ -740,68 +740,111 @@ static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack, return r; } -static uint64_t client_compute_timeout(uint64_t request_sent, - uint32_t lifetime) { - return request_sent + (lifetime - 3) * USEC_PER_SEC + +static uint64_t client_compute_timeout(sd_dhcp_client *client, + uint32_t lifetime, double factor) { + assert(client); + assert(client->request_sent); + assert(lifetime); + + return client->request_sent + ((lifetime - 3) * USEC_PER_SEC * factor) + + (random_u32() & 0x1fffff); } -static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec) { - uint64_t next_timeout; +static int client_set_lease_timeouts(sd_dhcp_client *client) { + usec_t time_now; + uint64_t lifetime_timeout; + uint64_t t2_timeout; + uint64_t t1_timeout; + char time_string[FORMAT_TIMESPAN_MAX]; int r; assert(client); assert(client->event); - - /* don't set timers for infinite leases */ - if (client->lease->lifetime == 0xffffffff) - return 0; - - if (client->lease->lifetime < 10) - return -EINVAL; + assert(client->lease); + assert(client->lease->lifetime); client->timeout_t1 = sd_event_source_unref(client->timeout_t1); client->timeout_t2 = sd_event_source_unref(client->timeout_t2); client->timeout_expire = sd_event_source_unref(client->timeout_expire); - if (!client->lease->t1) - client->lease->t1 = client->lease->lifetime / 2; + /* don't set timers for infinite leases */ + if (client->lease->lifetime == 0xffffffff) + return 0; - next_timeout = client_compute_timeout(client->request_sent, - client->lease->t1); - if (next_timeout < usec) - return -EINVAL; + r = sd_event_get_now_monotonic(client->event, &time_now); + if (r < 0) + return r; + assert(client->request_sent <= time_now); + + /* convert the various timeouts from relative (secs) to absolute (usecs) */ + lifetime_timeout = client_compute_timeout(client, client->lease->lifetime, 1); + if (client->lease->t1 && client->lease->t2) { + /* both T1 and T2 are given */ + if (client->lease->t1 < client->lease->t2 && + client->lease->t2 < client->lease->lifetime) { + /* they are both valid */ + t2_timeout = client_compute_timeout(client, client->lease->t2, 1); + t1_timeout = client_compute_timeout(client, client->lease->t1, 1); + } else { + /* discard both */ + t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0); + client->lease->t2 = (client->lease->lifetime * 7) / 8; + t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5); + client->lease->t1 = client->lease->lifetime / 2; + } + } else if (client->lease->t2 && client->lease->t2 < client->lease->lifetime) { + /* only T2 is given, and it is valid */ + t2_timeout = client_compute_timeout(client, client->lease->t2, 1); + t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5); + client->lease->t1 = client->lease->lifetime / 2; + if (t2_timeout <= t1_timeout) { + /* the computed T1 would be invalid, so discard T2 */ + t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0); + client->lease->t2 = (client->lease->lifetime * 7) / 8; + } + } else if (client->lease->t1 && client->lease->t1 < client->lease->lifetime) { + /* only T1 is given, and it is valid */ + t1_timeout = client_compute_timeout(client, client->lease->t1, 1); + t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0); + client->lease->t2 = (client->lease->lifetime * 7) / 8; + if (t2_timeout <= t1_timeout) { + /* the computed T2 would be invalid, so discard T1 */ + t2_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5); + client->lease->t2 = client->lease->lifetime / 2; + } + } else { + /* fall back to the default timeouts */ + t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5); + client->lease->t1 = client->lease->lifetime / 2; + t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0); + client->lease->t2 = (client->lease->lifetime * 7) / 8; + } + /* arm lifetime timeout */ r = sd_event_add_monotonic(client->event, - &client->timeout_t1, - next_timeout, + &client->timeout_expire, lifetime_timeout, 10 * USEC_PER_MSEC, - client_timeout_t1, client); + client_timeout_expire, client); if (r < 0) return r; - r = sd_event_source_set_priority(client->timeout_t1, + r = sd_event_source_set_priority(client->timeout_expire, client->event_priority); if (r < 0) return r; - if (!client->lease->t2) - client->lease->t2 = client->lease->lifetime * 7 / 8; - - if (client->lease->t2 < client->lease->t1) - return -EINVAL; + log_dhcp_client(client, "lease expires in %s", + format_timespan(time_string, FORMAT_TIMESPAN_MAX, + lifetime_timeout - time_now, 0)); - if (client->lease->lifetime < client->lease->t2) - return -EINVAL; - - next_timeout = client_compute_timeout(client->request_sent, - client->lease->t2); - if (next_timeout < usec) - return -EINVAL; + /* don't arm earlier timeouts if this has already expired */ + if (lifetime_timeout <= time_now) + return 0; + /* arm T2 timeout */ r = sd_event_add_monotonic(client->event, &client->timeout_t2, - next_timeout, + t2_timeout, 10 * USEC_PER_MSEC, client_timeout_t2, client); if (r < 0) @@ -812,28 +855,37 @@ static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec) { if (r < 0) return r; - next_timeout = client_compute_timeout(client->request_sent, - client->lease->lifetime); - if (next_timeout < usec) - return -EINVAL; + log_dhcp_client(client, "T2 expires in %s", + format_timespan(time_string, FORMAT_TIMESPAN_MAX, + t2_timeout - time_now, 0)); + + /* don't arm earlier timeout if this has already expired */ + if (t2_timeout <= time_now) + return 0; + /* arm T1 timeout */ r = sd_event_add_monotonic(client->event, - &client->timeout_expire, next_timeout, + &client->timeout_t1, + t1_timeout, 10 * USEC_PER_MSEC, - client_timeout_expire, client); + client_timeout_t1, client); if (r < 0) return r; - r = sd_event_source_set_priority(client->timeout_expire, + r = sd_event_source_set_priority(client->timeout_t1, client->event_priority); if (r < 0) return r; + log_dhcp_client(client, "T1 expires in %s", + format_timespan(time_string, FORMAT_TIMESPAN_MAX, + t1_timeout - time_now, 0)); + return 0; } static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, - int len, usec_t time_now) { + int len) { int r = 0, notify_event = 0; assert(client); @@ -932,7 +984,7 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message, client->last_addr = client->lease->address; - r = client_set_lease_timeouts(client, time_now); + r = client_set_lease_timeouts(client); if (r < 0) goto error; @@ -967,11 +1019,9 @@ static int client_receive_message_udp(sd_event_source *s, int fd, sd_dhcp_client *client = userdata; _cleanup_free_ DHCPMessage *message = NULL; int buflen = 0, len, r; - usec_t time_now; assert(s); assert(client); - assert(client->event); r = ioctl(fd, FIONREAD, &buflen); if (r < 0 || buflen <= 0) @@ -985,19 +1035,13 @@ static int client_receive_message_udp(sd_event_source *s, int fd, if (len < 0) return 0; - r = sd_event_get_now_monotonic(client->event, &time_now); - if (r < 0) - return client_stop(client, r); - - return client_handle_message(client, message, len, - time_now); + return client_handle_message(client, message, len); } static int client_receive_message_raw(sd_event_source *s, int fd, uint32_t revents, void *userdata) { sd_dhcp_client *client = userdata; _cleanup_free_ DHCPPacket *packet = NULL; - usec_t time_now; uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))]; struct iovec iov = {}; struct msghdr msg = { @@ -1012,7 +1056,6 @@ static int client_receive_message_raw(sd_event_source *s, int fd, assert(s); assert(client); - assert(client->event); r = ioctl(fd, FIONREAD, &buflen); if (r < 0 || buflen <= 0) @@ -1047,11 +1090,7 @@ static int client_receive_message_raw(sd_event_source *s, int fd, len -= DHCP_IP_UDP_SIZE; - r = sd_event_get_now_monotonic(client->event, &time_now); - if (r < 0) - return client_stop(client, r); - - return client_handle_message(client, &packet->dhcp, len, time_now); + return client_handle_message(client, &packet->dhcp, len); } int sd_dhcp_client_start(sd_dhcp_client *client) { |