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sd-dhcp-client: only verify UDP messages

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RAW messages are verified by the BPF in the kernel.
This commit is contained in:
Tom Gundersen
2014-07-28 10:44:51 +02:00
parent 36dd072cdf
commit 9fbc25232c
1 changed files with 32 additions and 30 deletions
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src/libsystemd-network/sd-dhcp-client.c
+32 -30
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@@ -1129,35 +1129,6 @@ static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
assert(client->event);
assert(message);
if (be32toh(message->magic) != DHCP_MAGIC_COOKIE) {
log_dhcp_client(client, "not a DHCP message: ignoring");
return 0;
}
if (message->op != BOOTREPLY) {
log_dhcp_client(client, "not a BOOTREPLY message: ignoring");
return 0;
}
if (be32toh(message->xid) != client->xid) {
log_dhcp_client(client, "received xid (%u) does not match "
"expected (%u): ignoring",
be32toh(message->xid), client->xid);
return 0;
}
if (message->htype != ARPHRD_ETHER || message->hlen != ETHER_ADDR_LEN) {
log_dhcp_client(client, "not an ethernet packet");
return 0;
}
if (memcmp(&message->chaddr[0], &client->client_id.mac_addr,
ETH_ALEN)) {
log_dhcp_client(client, "received chaddr does not match "
"expected: ignoring");
return 0;
}
switch (client->state) {
case DHCP_STATE_SELECTING:
@@ -1290,8 +1261,39 @@ static int client_receive_message_udp(sd_event_source *s, int fd,
log_dhcp_client(client, "could not receive message from UDP "
"socket: %m");
return 0;
} else if ((size_t)len < sizeof(DHCPMessage))
} else if ((size_t)len < sizeof(DHCPMessage)) {
log_dhcp_client(client, "too small to be a DHCP message: ignoring");
return 0;
}
if (be32toh(message->magic) != DHCP_MAGIC_COOKIE) {
log_dhcp_client(client, "not a DHCP message: ignoring");
return 0;
}
if (message->op != BOOTREPLY) {
log_dhcp_client(client, "not a BOOTREPLY message: ignoring");
return 0;
}
if (be32toh(message->xid) != client->xid) {
log_dhcp_client(client, "received xid (%u) does not match "
"expected (%u): ignoring",
be32toh(message->xid), client->xid);
return 0;
}
if (message->htype != ARPHRD_ETHER || message->hlen != ETHER_ADDR_LEN) {
log_dhcp_client(client, "not an ethernet packet");
return 0;
}
if (memcmp(&message->chaddr[0], &client->client_id.mac_addr,
ETH_ALEN)) {
log_dhcp_client(client, "received chaddr does not match "
"expected: ignoring");
return 0;
}
return client_handle_message(client, message, len);
}