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[dhcp6relay] Add dhcpv6 option check (#10486) (#10808)

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kellyyeh 2022-06-01 14:20:26 -07:00 committed by GitHub
parent 148ff285a6
commit 79555c894a
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 55 additions and 20 deletions
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70
src/dhcp6relay/src/relay.cpp
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@ -49,18 +49,21 @@ const struct sock_fprog ether_relay_fprog = {
/* DHCPv6 Counter */
uint64_t counters[DHCPv6_MESSAGE_TYPE_COUNT];
std::map<int, std::string> counterMap = {{0, "Unknown"},
{1, "Solicit"},
{2, "Advertise"},
{3, "Request"},
{4, "Confirm"},
{5, "Renew"},
{6, "Rebind"},
{7, "Reply"},
{8, "Release"},
{9, "Decline"},
{12, "Relay-Forward"},
{13, "Relay-Reply"}};
std::map<int, std::string> counterMap = {{DHCPv6_MESSAGE_TYPE_UNKNOWN, "Unknown"},
{DHCPv6_MESSAGE_TYPE_SOLICIT, "Solicit"},
{DHCPv6_MESSAGE_TYPE_ADVERTISE, "Advertise"},
{DHCPv6_MESSAGE_TYPE_REQUEST, "Request"},
{DHCPv6_MESSAGE_TYPE_CONFIRM, "Confirm"},
{DHCPv6_MESSAGE_TYPE_RENEW, "Renew"},
{DHCPv6_MESSAGE_TYPE_REBIND, "Rebind"},
{DHCPv6_MESSAGE_TYPE_REPLY, "Reply"},
{DHCPv6_MESSAGE_TYPE_RELEASE, "Release"},
{DHCPv6_MESSAGE_TYPE_DECLINE, "Decline"},
{DHCPv6_MESSAGE_TYPE_RECONFIGURE, "Reconfigure"},
{DHCPv6_MESSAGE_TYPE_INFORMATION_REQUEST, "Information-Request"},
{DHCPv6_MESSAGE_TYPE_RELAY_FORW, "Relay-Forward"},
{DHCPv6_MESSAGE_TYPE_RELAY_REPL, "Relay-Reply"},
{DHCPv6_MESSAGE_TYPE_MALFORMED, "Malformed"}};
/**
* @code void initialize_counter(swss::DBConnector *db, std::string counterVlan);
@ -83,8 +86,11 @@ void initialize_counter(swss::DBConnector *db, std::string counterVlan) {
db->hset(counterVlan, "Reply", toString(counters[DHCPv6_MESSAGE_TYPE_REPLY]));
db->hset(counterVlan, "Release", toString(counters[DHCPv6_MESSAGE_TYPE_RELEASE]));
db->hset(counterVlan, "Decline", toString(counters[DHCPv6_MESSAGE_TYPE_DECLINE]));
db->hset(counterVlan, "Reconfigure", toString(counters[DHCPv6_MESSAGE_TYPE_RECONFIGURE]));
db->hset(counterVlan, "Information-Request", toString(counters[DHCPv6_MESSAGE_TYPE_INFORMATION_REQUEST]));
db->hset(counterVlan, "Relay-Forward", toString(counters[DHCPv6_MESSAGE_TYPE_RELAY_FORW]));
db->hset(counterVlan, "Relay-Reply", toString(counters[DHCPv6_MESSAGE_TYPE_RELAY_REPL]));
db->hset(counterVlan, "Malformed", toString(counters[DHCPv6_MESSAGE_TYPE_MALFORMED]));
}
/**
@ -202,11 +208,12 @@ const struct dhcpv6_relay_msg *parse_dhcpv6_relay(const uint8_t *buffer) {
* @return dhcpv6_option end of dhcpv6 message option
*/
const struct dhcpv6_option *parse_dhcpv6_opt(const uint8_t *buffer, const uint8_t **out_end) {
uint32_t size = 4; // option-code + option-len
size += ntohs(*(uint16_t *)(buffer + 2));
(*out_end) = buffer + size;
auto option = (const struct dhcpv6_option *)buffer;
uint8_t size = 4; // option-code + option-len
size += *(uint16_t *)(buffer);
(*out_end) = buffer + size + ntohs(option->option_length);
return (const struct dhcpv6_option *)buffer;
return option;
}
/**
@ -587,6 +594,7 @@ void relay_relay_forw(int sock, const uint8_t *msg, int32_t len, const ip6_hdr *
void callback(evutil_socket_t fd, short event, void *arg) {
struct relay_config *config = (struct relay_config *)arg;
static uint8_t message_buffer[4096];
std::string counterVlan = counter_table;
int32_t len = recv(config->filter, message_buffer, 4096, 0);
if (len <= 0) {
syslog(LOG_WARNING, "recv: Failed to receive data at filter socket: %s\n", strerror(errno));
@ -622,9 +630,7 @@ void callback(evutil_socket_t fd, short event, void *arg) {
current_position = tmp;
auto msg = parse_dhcpv6_hdr(current_position);
counters[msg->msg_type]++;
std::string counterVlan = counter_table;
update_counter(config->db, counterVlan.append(config->interface), msg->msg_type);
auto option_position = current_position + sizeof(struct dhcpv6_msg);
switch (msg->msg_type) {
case DHCPv6_MESSAGE_TYPE_RELAY_FORW:
@ -632,9 +638,33 @@ void callback(evutil_socket_t fd, short event, void *arg) {
relay_relay_forw(config->local_sock, current_position, ntohs(udp_header->len) - sizeof(udphdr), ip_header, config);
break;
}
case DHCPv6_MESSAGE_TYPE_SOLICIT:
case DHCPv6_MESSAGE_TYPE_REQUEST:
case DHCPv6_MESSAGE_TYPE_CONFIRM:
case DHCPv6_MESSAGE_TYPE_RENEW:
case DHCPv6_MESSAGE_TYPE_REBIND:
case DHCPv6_MESSAGE_TYPE_RELEASE:
case DHCPv6_MESSAGE_TYPE_DECLINE:
case DHCPv6_MESSAGE_TYPE_INFORMATION_REQUEST:
{
while (option_position - message_buffer < len) {
auto option = parse_dhcpv6_opt(option_position, &tmp);
option_position = tmp;
if (ntohs(option->option_code) > DHCPv6_OPTION_LIMIT) {
counters[DHCPv6_MESSAGE_TYPE_MALFORMED]++;
update_counter(config->db, counterVlan.append(config->interface), DHCPv6_MESSAGE_TYPE_MALFORMED);
syslog(LOG_WARNING, "DHCPv6 option is invalid or contains malformed payload\n");
return;
}
}
counters[msg->msg_type]++;
update_counter(config->db, counterVlan.append(config->interface), msg->msg_type);
relay_client(config->local_sock, current_position, ntohs(udp_header->len) - sizeof(udphdr), ip_header, ether_header, config);
break;
}
default:
{
relay_client(config->local_sock, current_position, ntohs(udp_header->len) - sizeof(udphdr), ip_header, ether_header, config);
syslog(LOG_WARNING, "DHCPv6 client message received was not relayed\n");
break;
}
}

5
src/dhcp6relay/src/relay.h
View File

@ -16,6 +16,7 @@
#define RELAY_PORT 547
#define CLIENT_PORT 546
#define HOP_LIMIT 8 //HOP_LIMIT reduced from 32 to 8 as stated in RFC8415
#define DHCPv6_OPTION_LIMIT 56 // DHCPv6 option code greater than 56 are currently unassigned
#define lengthof(A) (sizeof (A) / sizeof (A)[0])
@ -35,8 +36,11 @@ typedef enum
DHCPv6_MESSAGE_TYPE_REPLY = 7,
DHCPv6_MESSAGE_TYPE_RELEASE = 8,
DHCPv6_MESSAGE_TYPE_DECLINE = 9,
DHCPv6_MESSAGE_TYPE_RECONFIGURE = 10,
DHCPv6_MESSAGE_TYPE_INFORMATION_REQUEST = 11,
DHCPv6_MESSAGE_TYPE_RELAY_FORW = 12,
DHCPv6_MESSAGE_TYPE_RELAY_REPL = 13,
DHCPv6_MESSAGE_TYPE_MALFORMED = 14,
DHCPv6_MESSAGE_TYPE_COUNT
} dhcp_message_type_t;
@ -58,6 +62,7 @@ struct relay_config {
struct dhcpv6_msg {
uint8_t msg_type;
uint8_t xid[3];
};
struct PACKED dhcpv6_relay_msg {