Backport dhcpserver changes from ourairquality's LwIP2 work

https://github.com/ourairquality/esp-open-rtos/blob/ourairquality/extras/dhcpserver/dhcpserver.c
This commit is contained in:
Sakari Kapanen 2017-08-04 00:38:13 +03:00
parent 9523e872f8
commit b979169e61
2 changed files with 90 additions and 42 deletions

View file

@ -14,17 +14,20 @@
* BSD Licensed as described in the file LICENSE
*/
#include <string.h>
#include <strings.h>
#include <FreeRTOS.h>
#include <task.h>
#include <lwip/netif.h>
#include <lwip/api.h>
#include "esplibs/libmain.h"
/* Grow the size of the lwip dhcp_msg struct's options field, as LWIP
defaults to a 68 octet options field for its DHCP client, and most
full-sized clients send us more than this. */
#define DHCP_OPTIONS_LEN 312
#include <lwip/ip.h>
#include <lwip/dhcp.h>
_Static_assert(sizeof(struct dhcp_msg) == offsetof(struct dhcp_msg, options) + 312, "dhcp_msg_t should have extended options size");
@ -35,6 +38,7 @@ _Static_assert(sizeof(struct dhcp_msg) == offsetof(struct dhcp_msg, options) + 3
typedef struct {
uint8_t hwaddr[NETIF_MAX_HWADDR_LEN];
uint8_t active;
uint32_t expires;
} dhcp_lease_t;
@ -44,6 +48,10 @@ typedef struct {
ip_addr_t first_client_addr;
struct netif *server_if;
dhcp_lease_t *leases; /* length max_leases */
/* Optional router */
ip_addr_t router;
/* Optional DNS server */
ip_addr_t dns;
} server_state_t;
/* Only one DHCP server task can run at once, so we have global state
@ -70,7 +78,7 @@ static dhcp_lease_t *find_lease_slot(uint8_t *hwaddr);
/* Copy IP address as dotted decimal to 'dest', must be at least 16 bytes long */
inline static void sprintf_ipaddr(const ip_addr_t *addr, char *dest)
{
if(addr == NULL)
if (addr == NULL)
sprintf(dest, "NULL");
else
sprintf(dest, "%d.%d.%d.%d", ip4_addr1(addr),
@ -80,34 +88,49 @@ inline static void sprintf_ipaddr(const ip_addr_t *addr, char *dest)
void dhcpserver_start(const ip_addr_t *first_client_addr, uint8_t max_leases)
{
/* Stop any existing running dhcpserver */
if(dhcpserver_task_handle)
if (dhcpserver_task_handle)
dhcpserver_stop();
state = malloc(sizeof(server_state_t));
state->max_leases = max_leases;
state->leases = calloc(max_leases, sizeof(dhcp_lease_t));
bzero(state->leases, max_leases * sizeof(dhcp_lease_t));
// state->server_if is assigned once the task is running - see comment in dhcpserver_task()
ip_addr_copy(state->first_client_addr, *first_client_addr);
xTaskCreate(dhcpserver_task, "DHCPServer", 768, NULL, 8, &dhcpserver_task_handle);
/* Clear options */
ip_addr_set_zero(&state->router);
ip_addr_set_zero(&state->dns);
xTaskCreate(dhcpserver_task, "DHCP Server", 448, NULL, 2, &dhcpserver_task_handle);
}
void dhcpserver_stop(void)
{
if(dhcpserver_task_handle) {
if (dhcpserver_task_handle) {
vTaskDelete(dhcpserver_task_handle);
free(state);
dhcpserver_task_handle = NULL;
}
}
void dhcpserver_set_router(const ip_addr_t *router)
{
ip_addr_copy(state->router, *router);
}
void dhcpserver_set_dns(const ip_addr_t *dns)
{
ip_addr_copy(state->dns, *dns);
}
static void dhcpserver_task(void *pxParameter)
{
/* netif_list isn't assigned until after user_init completes, which is why we do it inside the task */
state->server_if = netif_list; /* TODO: Make this configurable */
state->nc = netconn_new (NETCONN_UDP);
if(!state->nc) {
if (!state->nc) {
printf("DHCP Server Error: Failed to allocate socket.\r\n");
return;
}
@ -121,29 +144,32 @@ static void dhcpserver_task(void *pxParameter)
/* Receive a DHCP packet */
err_t err = netconn_recv(state->nc, &netbuf);
if(err != ERR_OK) {
if (err != ERR_OK) {
printf("DHCP Server Error: Failed to receive DHCP packet. err=%d\r\n", err);
continue;
}
/* expire any leases that have passed */
uint32_t now = xTaskGetTickCount();
for(int i = 0; i < state->max_leases; i++) {
uint32_t expires = state->leases[i].expires;
if(expires && expires < now)
state->leases[i].expires = 0;
for (int i = 0; i < state->max_leases; i++) {
if (state->leases[i].active) {
uint32_t expires = state->leases[i].expires - now;
if (expires >= 0x80000000) {
state->leases[i].active = 0;
}
}
}
ip_addr_t received_ip;
u16_t port;
netconn_addr(state->nc, &received_ip, &port);
if(netbuf_len(netbuf) < offsetof(struct dhcp_msg, options)) {
if (netbuf_len(netbuf) < offsetof(struct dhcp_msg, options)) {
/* too short to be a valid DHCP client message */
netbuf_delete(netbuf);
continue;
}
if(netbuf_len(netbuf) >= sizeof(struct dhcp_msg)) {
if (netbuf_len(netbuf) >= sizeof(struct dhcp_msg)) {
printf("DHCP Server Warning: Client sent more options than we know how to parse. len=%d\r\n", netbuf_len(netbuf));
}
@ -152,18 +178,18 @@ static void dhcpserver_task(void *pxParameter)
uint8_t *message_type = find_dhcp_option(&received, DHCP_OPTION_MESSAGE_TYPE,
DHCP_OPTION_MESSAGE_TYPE_LEN, NULL);
if(!message_type) {
if (!message_type) {
printf("DHCP Server Error: No message type field found");
continue;
}
printf("State dump. Message type %d\n", *message_type);
for(int i = 0; i < state->max_leases; i++) {
for (int i = 0; i < state->max_leases; i++) {
dhcp_lease_t *lease = &state->leases[i];
printf("lease slot %d expiry %d hwaddr %02x:%02x:%02x:%02x:%02x:%02x\r\n", i, lease->expires, lease->hwaddr[0],
lease->hwaddr[1], lease->hwaddr[2], lease->hwaddr[3], lease->hwaddr[4],
lease->hwaddr[5]);
printf("lease slot %d active %d expiry %d hwaddr %02x:%02x:%02x:%02x:%02x:%02x\r\n", i,
lease->active, lease->expires - now,
lease->hwaddr[0], lease->hwaddr[1], lease->hwaddr[2],
lease->hwaddr[3], lease->hwaddr[4], lease->hwaddr[5]);
}
switch(*message_type) {
@ -184,13 +210,13 @@ static void dhcpserver_task(void *pxParameter)
static void handle_dhcp_discover(struct dhcp_msg *dhcpmsg)
{
if(dhcpmsg->htype != DHCP_HTYPE_ETH)
if (dhcpmsg->htype != DHCP_HTYPE_ETH)
return;
if(dhcpmsg->hlen > NETIF_MAX_HWADDR_LEN)
if (dhcpmsg->hlen > NETIF_MAX_HWADDR_LEN)
return;
dhcp_lease_t *freelease = find_lease_slot(dhcpmsg->chaddr);
if(!freelease) {
if (!freelease) {
printf("DHCP Server: All leases taken.\r\n");
return; /* Nothing available, so do nothing */
}
@ -199,13 +225,19 @@ static void handle_dhcp_discover(struct dhcp_msg *dhcpmsg)
dhcpmsg->op = DHCP_BOOTREPLY;
bzero(dhcpmsg->options, DHCP_OPTIONS_LEN);
ip_addr_copy(dhcpmsg->yiaddr, state->first_client_addr);
ip4_addr4(&(dhcpmsg->yiaddr)) += (freelease - state->leases);
dhcpmsg->yiaddr.addr = lwip_htonl(lwip_ntohl(state->first_client_addr.addr) + (freelease - state->leases));
uint8_t *opt = (uint8_t *)&dhcpmsg->options;
opt = add_dhcp_option_byte(opt, DHCP_OPTION_MESSAGE_TYPE, DHCP_OFFER);
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_SERVER_ID, &state->server_if->ip_addr, 4);
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_SUBNET_MASK, &state->server_if->netmask, 4);
if (!ip_addr_isany(&state->router)) {
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_ROUTER, &state->router, 4);
}
if (!ip_addr_isany(&state->dns)) {
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_DNS_SERVER, &state->dns, 4);
}
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_END, NULL, 0);
struct netbuf *netbuf = netbuf_new();
@ -218,16 +250,16 @@ static void handle_dhcp_discover(struct dhcp_msg *dhcpmsg)
static void handle_dhcp_request(struct dhcp_msg *dhcpmsg)
{
static char ipbuf[16];
if(dhcpmsg->htype != DHCP_HTYPE_ETH)
if (dhcpmsg->htype != DHCP_HTYPE_ETH)
return;
if(dhcpmsg->hlen > NETIF_MAX_HWADDR_LEN)
if (dhcpmsg->hlen > NETIF_MAX_HWADDR_LEN)
return;
ip_addr_t requested_ip;
uint8_t *requested_ip_opt = find_dhcp_option(dhcpmsg, DHCP_OPTION_REQUESTED_IP, 4, NULL);
if(requested_ip_opt) {
if (requested_ip_opt) {
memcpy(&requested_ip.addr, requested_ip_opt, 4);
} else if(ip_addr_cmp(&requested_ip, IP_ADDR_ANY)) {
} else if (ip_addr_cmp(&requested_ip, IP_ADDR_ANY)) {
ip_addr_copy(requested_ip, dhcpmsg->ciaddr);
} else {
printf("DHCP Server Error: No requested IP\r\n");
@ -236,7 +268,7 @@ static void handle_dhcp_request(struct dhcp_msg *dhcpmsg)
}
/* Test the first 4 octets match */
if(ip4_addr1(&requested_ip) != ip4_addr1(&state->first_client_addr)
if (ip4_addr1(&requested_ip) != ip4_addr1(&state->first_client_addr)
|| ip4_addr2(&requested_ip) != ip4_addr2(&state->first_client_addr)
|| ip4_addr3(&requested_ip) != ip4_addr3(&state->first_client_addr)) {
sprintf_ipaddr(&requested_ip, ipbuf);
@ -246,14 +278,14 @@ static void handle_dhcp_request(struct dhcp_msg *dhcpmsg)
}
/* Test the last octet is in the MAXCLIENTS range */
int16_t octet_offs = ip4_addr4(&requested_ip) - ip4_addr4(&state->first_client_addr);
if(octet_offs < 0 || octet_offs >= state->max_leases) {
if (octet_offs < 0 || octet_offs >= state->max_leases) {
printf("DHCP Server Error: Address out of range\r\n");
send_dhcp_nak(dhcpmsg);
return;
}
dhcp_lease_t *requested_lease = state->leases + octet_offs;
if(requested_lease->expires != 0 && memcmp(requested_lease->hwaddr, dhcpmsg->chaddr,dhcpmsg->hlen))
if (requested_lease->active && memcmp(requested_lease->hwaddr, dhcpmsg->chaddr,dhcpmsg->hlen))
{
printf("DHCP Server Error: Lease for address already taken\r\n");
send_dhcp_nak(dhcpmsg);
@ -265,7 +297,9 @@ static void handle_dhcp_request(struct dhcp_msg *dhcpmsg)
printf("DHCP lease addr %s assigned to MAC %02x:%02x:%02x:%02x:%02x:%02x\r\n", ipbuf, requested_lease->hwaddr[0],
requested_lease->hwaddr[1], requested_lease->hwaddr[2], requested_lease->hwaddr[3], requested_lease->hwaddr[4],
requested_lease->hwaddr[5]);
requested_lease->expires = DHCPSERVER_LEASE_TIME * configTICK_RATE_HZ;
uint32_t now = xTaskGetTickCount();
requested_lease->expires = now + DHCPSERVER_LEASE_TIME * configTICK_RATE_HZ;
requested_lease->active = 1;
/* Reuse the REQUEST message as the ACK message */
dhcpmsg->op = DHCP_BOOTREPLY;
@ -279,6 +313,13 @@ static void handle_dhcp_request(struct dhcp_msg *dhcpmsg)
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_LEASE_TIME, &expiry, 4);
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_SERVER_ID, &state->server_if->ip_addr, 4);
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_SUBNET_MASK, &state->server_if->netmask, 4);
if (!ip_addr_isany(&state->router)) {
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_ROUTER, &state->router, 4);
}
if (!ip_addr_isany(&state->dns)) {
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_DNS_SERVER, &state->dns, 4);
}
opt = add_dhcp_option_bytes(opt, DHCP_OPTION_END, NULL, 0);
struct netbuf *netbuf = netbuf_new();
@ -291,7 +332,8 @@ static void handle_dhcp_request(struct dhcp_msg *dhcpmsg)
static void handle_dhcp_release(struct dhcp_msg *dhcpmsg)
{
dhcp_lease_t *lease = find_lease_slot(dhcpmsg->chaddr);
if(lease) {
if (lease) {
lease->active = 0;
lease->expires = 0;
}
}
@ -319,17 +361,17 @@ static uint8_t *find_dhcp_option(struct dhcp_msg *msg, uint8_t option_num, uint8
uint8_t *start = (uint8_t *)&msg->options;
uint8_t *msg_end = (uint8_t *)msg + sizeof(struct dhcp_msg);
for(uint8_t *p = start; p < msg_end-2;) {
for (uint8_t *p = start; p < msg_end-2;) {
uint8_t type = *p++;
uint8_t len = *p++;
if(type == DHCP_OPTION_END)
if (type == DHCP_OPTION_END)
return NULL;
if(p+len >= msg_end)
if (p+len >= msg_end)
break; /* We've overrun our valid DHCP message size, or this isn't a valid option */
if(type == option_num) {
if(len < min_length)
if (type == option_num) {
if (len < min_length)
break;
if(length)
if (length)
*length = len;
return p; /* start of actual option data */
}
@ -349,7 +391,7 @@ static uint8_t *add_dhcp_option_byte(uint8_t *opt, uint8_t type, uint8_t value)
static uint8_t *add_dhcp_option_bytes(uint8_t *opt, uint8_t type, void *value, uint8_t len)
{
*opt++ = type;
if(len) {
if (len) {
*opt++ = len;
memcpy(opt, value, len);
}
@ -360,8 +402,8 @@ static uint8_t *add_dhcp_option_bytes(uint8_t *opt, uint8_t type, void *value, u
static dhcp_lease_t *find_lease_slot(uint8_t *hwaddr)
{
dhcp_lease_t *empty_lease = NULL;
for(int i = 0; i < state->max_leases; i++) {
if(state->leases[i].expires == 0 && !empty_lease)
for (int i = 0; i < state->max_leases; i++) {
if (!state->leases[i].active && !empty_lease)
empty_lease = &state->leases[i];
else if (memcmp(hwaddr, state->leases[i].hwaddr, 6) == 0)
return &state->leases[i];

View file

@ -34,6 +34,12 @@ void dhcpserver_get_lease(const ip_addr_t *first_client_addr, uint8_t max_leases
*/
void dhcpserver_stop(void);
/* Set a router address to send as an option. */
void dhcpserver_set_router(const ip_addr_t *router);
/* Set a DNS address to send as an option. */
void dhcpserver_set_dns(const ip_addr_t *dns);
#ifdef __cplusplus
}
#endif