DHCPV4: add function ValidateOptions()
This add a new function ValidateOptions() in DHCPV4.
Codes for validating the DHCP options are removed and
unified into this new function.
Bug: 25642025
TEST=compile, unittest, and run it.
Change-Id: I92438469e6b1a0b1558a125dda2768db6f1092a1
diff --git a/dhcpv4.cc b/dhcpv4.cc
index cc9e621..dce3191 100644
--- a/dhcpv4.cc
+++ b/dhcpv4.cc
@@ -264,25 +264,9 @@
}
LOG(INFO) << "Lease IP: " << IPtoString(your_ip_address);
- uint32_t lease_time = msg.lease_time();
- if (lease_time == 0) {
- LOG(ERROR) << "Reject invalid lease time from server";
+ if (!ValidateOptions(msg)) {
return;
}
- LOG(INFO) << "Lease Time: " << lease_time;
-
- if (msg.subnet_mask() == 0) {
- LOG(ERROR) << "Reject invalid subnet mask from server";
- return;
- }
- LOG(INFO) << "Subnet Mask: " << IPtoString(msg.subnet_mask());
-
- if (msg.interface_mtu() == 0) {
- LOG(WARNING) << "Failed to get a valid Interface MTU from server";
- // Shill will use a default MTU
- // in case no MTU is provided by DHCP.
- }
- LOG(INFO) << "Interface MTU: " << msg.interface_mtu();
// Accept this offer.
LOG(INFO) << "Accept offer with ip: " << IPtoString(your_ip_address);
@@ -326,51 +310,14 @@
}
LOG(INFO) << "Lease IP: " << IPtoString(your_ip_address);
- uint32_t lease_time = msg.lease_time();
- if (lease_time == 0 && state_ == State::REQUEST) {
- LOG(ERROR) << "Reject invalid lease time from server";
+ if (!ValidateOptions(msg)) {
return;
}
- LOG(INFO) << "Lease Time: " << lease_time;
-
- if (msg.subnet_mask() != subnet_mask_) {
- LOG(ERROR) << "Reject invalid subnet mask from server";
- return;
- }
- LOG(INFO) << "Subnet Mask: " << IPtoString(msg.subnet_mask());
-
- if (msg.interface_mtu() == 0) {
- LOG(WARNING) << "Failed to get a valid Interface MTU from server";
- // Shill will use a default MTU
- // in case no MTU is provided by DHCP.
- }
- LOG(INFO) << "Interface MTU: " << msg.interface_mtu();
-
- std::vector<uint32_t> router = msg.router();
- if (router.size() == 0) {
- LOG(ERROR) << "Failed to get default gateway address from DHCP Ack";
- return;
- }
- LOG(INFO) << "Routers:";
- for (uint32_t ip : router) {
- LOG(INFO) << IPtoString(ip);
- }
-
- std::vector<uint32_t> dns_server = msg.dns_server();
- if (dns_server.size() == 0) {
- LOG(WARNING) << "Failed to get DNS server address from DHCP Ack";
- // Shill will use Google DNS server
- // in case no DNS server is provided by DHCP.
- } else {
- LOG(INFO) << "DNS Server:";
- for (uint32_t ip : dns_server) {
- LOG(INFO) << IPtoString(ip);
- }
- }
// TODO(nywang): Validate the ip address using ARP.
// TODO(nywang): Validate the gateway address using ARP.
// Accept the ACK.
+ uint32_t lease_time = msg.lease_time();
uint32_t renewal_time = lease_time * kRenewalTimePercentage / 100;
uint32_t rebinding_time = lease_time * kRebindTimePercentage / 100;
// Override the renewal time or rebinding time if ACK specifies the value.
@@ -613,6 +560,51 @@
return true;
}
+bool DHCPV4::ValidateOptions(const DHCPMessage& msg) {
+ uint32_t lease_time = msg.lease_time();
+ if (lease_time == 0) {
+ LOG(ERROR) << "Reject invalid lease time";
+ return false;
+ }
+ LOG(INFO) << "Lease Time: " << lease_time;
+
+ if (msg.subnet_mask() == 0) {
+ LOG(ERROR) << "Reject invalid subnet mask";
+ return false;
+ }
+ LOG(INFO) << "Subnet Mask: " << IPtoString(msg.subnet_mask());
+
+ if (msg.interface_mtu() == 0) {
+ LOG(WARNING) << "Failed to get a valid Interface MTU";
+ // Shill will use a default MTU
+ // in case no MTU is provided by DHCP.
+ }
+ LOG(INFO) << "Interface MTU: " << msg.interface_mtu();
+
+ std::vector<uint32_t> router = msg.router();
+ if (router.size() == 0) {
+ LOG(ERROR) << "Failed to get default gateway address";
+ return false;
+ }
+ LOG(INFO) << "Routers:";
+ for (uint32_t ip : router) {
+ LOG(INFO) << IPtoString(ip);
+ }
+
+ std::vector<uint32_t> dns_server = msg.dns_server();
+ if (dns_server.size() == 0) {
+ LOG(WARNING) << "Failed to get DNS server address";
+ // Shill will use Google DNS server
+ // in case no DNS server is provided by DHCP.
+ } else {
+ LOG(INFO) << "DNS Server:";
+ for (uint32_t ip : dns_server) {
+ LOG(INFO) << IPtoString(ip);
+ }
+ }
+ return true;
+}
+
int DHCPV4::ValidatePacketHeader(const unsigned char* buffer, size_t len) {
const struct iphdr* ip =
reinterpret_cast<const struct iphdr*>(buffer);
diff --git a/dhcpv4.h b/dhcpv4.h
index 5d45a92..78903d7 100644
--- a/dhcpv4.h
+++ b/dhcpv4.h
@@ -62,6 +62,7 @@
// Validate the IP and UDP header and return the total headers length.
// Return -1 if any header is invalid.
int ValidatePacketHeader(const unsigned char* buffer, size_t len);
+ bool ValidateOptions(const DHCPMessage& msg);
void ResetStateVariables();
const std::string IPtoString(uint32_t ip);
