diff options
| author | Lennart Poettering <lennart@poettering.net> | 2015-08-27 01:59:43 +0200 |
|---|---|---|
| committer | Lennart Poettering <lennart@poettering.net> | 2015-08-27 01:59:43 +0200 |
| commit | fbcd420aa407dc3c16efd9fb32cbae6d04d4f65d (patch) | |
| tree | 1fef6dd487d0aa4f2abe5541a5ba7a77c9d66186 | |
| parent | 586ac6f711e2eccceb12421df22fca4f117226c4 (diff) | |
dhcp: don't underflow in lease time calculations
Don't underflow when calculating lease time.
| -rw-r--r-- | src/libsystemd-network/sd-dhcp-client.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c index 008b21c3b8..c12768cf0e 100644 --- a/src/libsystemd-network/sd-dhcp-client.c +++ b/src/libsystemd-network/sd-dhcp-client.c @@ -1163,13 +1163,17 @@ static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack, return r; } -static uint64_t client_compute_timeout(sd_dhcp_client *client, - uint32_t lifetime, double factor) { +static uint64_t client_compute_timeout(sd_dhcp_client *client, uint32_t lifetime, double factor) { assert(client); assert(client->request_sent); - assert(lifetime); + assert(lifetime > 0); - return client->request_sent + ((lifetime - 3) * USEC_PER_SEC * factor) + + if (lifetime > 3) + lifetime -= 3; + else + lifetime = 0; + + return client->request_sent + (lifetime * USEC_PER_SEC * factor) + + (random_u32() & 0x1fffff); } @@ -1201,7 +1205,7 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) { /* 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) { + if (client->lease->t1 > 0 && client->lease->t2 > 0) { /* both T1 and T2 are given */ if (client->lease->t1 < client->lease->t2 && client->lease->t2 < client->lease->lifetime) { @@ -1215,7 +1219,7 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) { 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) { + } else if (client->lease->t2 > 0 && 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); @@ -1225,7 +1229,7 @@ static int client_set_lease_timeouts(sd_dhcp_client *client) { 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) { + } else if (client->lease->t1 > 0 && 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); |