Diff: modules/pico_dhcp_server.c

Revision:

1:cfe8984a32b4

Parent:

0:d7f2341ab245

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/modules/pico_dhcp_server.c	Fri May 17 12:09:59 2013 +0000
@@ -0,0 +1,290 @@
+/*********************************************************************
+PicoTCP. Copyright (c) 2012 TASS Belgium NV. Some rights reserved.
+See LICENSE and COPYING for usage.
+
+
+Authors: Frederik Van Slycken, Kristof Roelants
+*********************************************************************/
+
+#ifdef PICO_SUPPORT_DHCPD
+
+#include "pico_dhcp_server.h"
+#include "pico_stack.h"
+#include "pico_config.h"
+#include "pico_addressing.h"
+#include "pico_socket.h"
+#include "pico_arp.h"
+#include <stdlib.h>
+
+# define dhcpd_dbg(...) do{}while(0)
+//# define dhcpd_dbg dbg
+
+#define dhcpd_make_offer(x) dhcpd_make_reply(x, PICO_DHCP_MSG_OFFER)
+#define dhcpd_make_ack(x) dhcpd_make_reply(x, PICO_DHCP_MSG_ACK)
+#define ip_inrange(x) ((long_be(x) >= long_be(dn->settings->pool_start)) && (long_be(x) <= long_be(dn->settings->pool_end)))
+
+static int dhcp_settings_cmp(void *ka, void *kb)
+{
+  struct pico_dhcpd_settings *a = ka, *b = kb;
+  if (a->dev < b->dev)
+    return -1; 
+  else if (a->dev > b->dev)
+    return 1;
+  else
+    return 0;
+} 
+PICO_TREE_DECLARE(DHCPSettings, dhcp_settings_cmp);
+
+static int dhcp_negotiations_cmp(void *ka, void *kb)
+{
+  struct pico_dhcp_negotiation *a = ka, *b = kb;
+  if (a->xid < b->xid)
+    return -1; 
+  else if (a->xid > b->xid)
+    return 1;
+  else
+    return 0;
+} 
+PICO_TREE_DECLARE(DHCPNegotiations, dhcp_negotiations_cmp);
+
+static struct pico_dhcp_negotiation *get_negotiation_by_xid(uint32_t xid)
+{
+  struct pico_dhcp_negotiation test = { }, *neg = NULL;
+
+  test.xid = xid;
+  neg = pico_tree_findKey(&DHCPNegotiations, &test);
+  if (!neg)
+    return NULL;
+  else
+    return neg;
+}
+
+static void dhcpd_make_reply(struct pico_dhcp_negotiation *dn, uint8_t reply_type)
+{
+  uint8_t buf_out[DHCPD_DATAGRAM_SIZE] = {0};
+  struct pico_dhcphdr *dh_out = (struct pico_dhcphdr *) buf_out;
+  struct pico_ip4 destination = { };
+  uint32_t bcast = dn->settings->my_ip.addr | ~(dn->settings->netmask.addr);
+  uint32_t dns_server = OPENDNS;
+  uint16_t port = PICO_DHCP_CLIENT_PORT;
+  int sent = 0;
+
+  memcpy(dh_out->hwaddr, dn->eth.addr, PICO_HLEN_ETHER);
+  dh_out->op = PICO_DHCP_OP_REPLY;
+  dh_out->htype = PICO_HTYPE_ETHER;
+  dh_out->hlen = PICO_HLEN_ETHER;
+  dh_out->xid = dn->xid;
+  dh_out->yiaddr = dn->ipv4.addr;
+  dh_out->siaddr = dn->settings->my_ip.addr;
+  dh_out->dhcp_magic = PICO_DHCPD_MAGIC_COOKIE;
+
+  /* Option: msg type, len 1 */
+  dh_out->options[0] = PICO_DHCPOPT_MSGTYPE;
+  dh_out->options[1] = 1;
+  dh_out->options[2] = reply_type;
+
+  /* Option: server id, len 4 */
+  dh_out->options[3] = PICO_DHCPOPT_SERVERID;
+  dh_out->options[4] = 4;
+  memcpy(dh_out->options + 5, &dn->settings->my_ip.addr, 4);
+
+  /* Option: Lease time, len 4 */
+  dh_out->options[9] = PICO_DHCPOPT_LEASETIME;
+  dh_out->options[10] = 4;
+  memcpy(dh_out->options + 11, &dn->settings->lease_time, 4);
+
+  /* Option: Netmask, len 4 */
+  dh_out->options[15] = PICO_DHCPOPT_NETMASK;
+  dh_out->options[16] = 4;
+  memcpy(dh_out->options + 17, &dn->settings->netmask.addr, 4);
+
+  /* Option: Router, len 4 */
+  dh_out->options[21] = PICO_DHCPOPT_ROUTER;
+  dh_out->options[22] = 4;
+  memcpy(dh_out->options + 23, &dn->settings->my_ip.addr, 4);
+
+  /* Option: Broadcast, len 4 */
+  dh_out->options[27] = PICO_DHCPOPT_BCAST;
+  dh_out->options[28] = 4;
+  memcpy(dh_out->options + 29, &bcast, 4);
+
+  /* Option: DNS, len 4 */
+  dh_out->options[33] = PICO_DHCPOPT_DNS;
+  dh_out->options[34] = 4;
+  memcpy(dh_out->options + 35, &dns_server, 4);
+
+  dh_out->options[40] = PICO_DHCPOPT_END;
+
+  destination.addr = dh_out->yiaddr;
+
+  sent = pico_socket_sendto(dn->settings->s, buf_out, DHCPD_DATAGRAM_SIZE, &destination, port);
+  if (sent < 0) {
+    dhcpd_dbg("DHCPD: sendto failed with code %d!\n", pico_err);
+  }
+}
+
+static void dhcp_recv(struct pico_socket *s, uint8_t *buffer, int len)
+{
+  struct pico_dhcphdr *dhdr = (struct pico_dhcphdr *) buffer;
+  struct pico_dhcp_negotiation *dn = get_negotiation_by_xid(dhdr->xid);
+  struct pico_ip4* ipv4 = NULL;
+  struct pico_dhcpd_settings test, *settings = NULL;
+  uint8_t *nextopt, opt_data[20], opt_type;
+  int opt_len = 20;
+
+  if (!is_options_valid(dhdr->options, len - sizeof(struct pico_dhcphdr))) {
+    dhcpd_dbg("DHCPD WARNING: invalid options in dhcp message\n");
+    return;
+  }
+
+  if (!dn) {
+    dn = pico_zalloc(sizeof(struct pico_dhcp_negotiation));
+    if (!dn) {
+      pico_err = PICO_ERR_ENOMEM;
+      return;
+    }
+    dn->xid = dhdr->xid;
+    dn->state = DHCPSTATE_DISCOVER;
+    memcpy(dn->eth.addr, dhdr->hwaddr, PICO_HLEN_ETHER);
+
+    test.dev = pico_ipv4_link_find(&s->local_addr.ip4);
+    settings = pico_tree_findKey(&DHCPSettings, &test);
+    if (settings) {
+      dn->settings = settings;
+    } else {
+      dhcpd_dbg("DHCPD WARNING: received DHCP message on unconfigured link %s\n", test.dev->name);
+      pico_free(dn);
+      return;
+    }
+
+    ipv4 = pico_arp_reverse_lookup(&dn->eth);
+    if (!ipv4) {
+      dn->ipv4.addr = settings->pool_next;
+      pico_arp_create_entry(dn->eth.addr, dn->ipv4, settings->dev);
+      settings->pool_next = long_be(long_be(settings->pool_next) + 1);
+    } else {
+      dn->ipv4.addr = ipv4->addr;
+    }
+
+    if (pico_tree_insert(&DHCPNegotiations, dn)) {
+      dhcpd_dbg("DHCPD WARNING: tried creating new negotation for existing xid %u\n", dn->xid);
+      pico_free(dn);
+      return; /* Element key already exists */
+    }
+  }
+ 
+  if (!ip_inrange(dn->ipv4.addr))
+    return;
+
+  opt_type = dhcp_get_next_option(dhdr->options, opt_data, &opt_len, &nextopt);
+  while (opt_type != PICO_DHCPOPT_END) {
+    /* parse interesting options here */
+    if (opt_type == PICO_DHCPOPT_MSGTYPE) {
+      /* server simple state machine */
+      uint8_t msg_type = opt_data[0];
+      if (msg_type == PICO_DHCP_MSG_DISCOVER) {
+        dhcpd_make_offer(dn);
+        dn->state = DHCPSTATE_OFFER;
+        return;
+      } else if ((msg_type == PICO_DHCP_MSG_REQUEST)&&( dn->state == DHCPSTATE_OFFER)) {
+        dhcpd_make_ack(dn);
+        dn->state = DHCPSTATE_BOUND;
+        return;
+      }
+    }
+    opt_len = 20;
+    opt_type = dhcp_get_next_option(NULL, opt_data, &opt_len, &nextopt);
+  }
+}
+
+static void pico_dhcpd_wakeup(uint16_t ev, struct pico_socket *s)
+{
+  uint8_t buf[DHCPD_DATAGRAM_SIZE] = { };
+  int r = 0;
+  uint32_t peer = 0;
+  uint16_t port = 0;
+
+  dhcpd_dbg("DHCPD: called dhcpd_wakeup\n");
+  if (ev == PICO_SOCK_EV_RD) {
+    do {
+      r = pico_socket_recvfrom(s, buf, DHCPD_DATAGRAM_SIZE, &peer, &port);
+      if (r > 0 && port == PICO_DHCP_CLIENT_PORT) {
+        dhcp_recv(s, buf, r);
+      }
+    } while(r>0);
+  }
+}
+
+int pico_dhcp_server_initiate(struct pico_dhcpd_settings *setting)
+{
+  struct pico_dhcpd_settings *settings = NULL;
+  struct pico_ipv4_link *link = NULL;
+  uint16_t port = PICO_DHCPD_PORT;
+
+  if (!setting) {
+    pico_err = PICO_ERR_EINVAL;
+    return -1;
+  }
+
+  if (!setting->my_ip.addr) {
+    pico_err = PICO_ERR_EINVAL;
+    dhcpd_dbg("DHCPD: IP address of interface was not supplied\n");
+    return -1;
+  }
+
+  link = pico_ipv4_link_get(&setting->my_ip);
+  if (!link) {
+    pico_err = PICO_ERR_EINVAL;
+    dhcpd_dbg("DHCPD: no link with IP %X found\n", setting->my_ip.addr);
+    return -1;
+  }
+
+  settings = pico_zalloc(sizeof(struct pico_dhcpd_settings));
+  if (!settings) {
+    pico_err = PICO_ERR_ENOMEM;
+    return -1;
+  }
+  memcpy(settings, setting, sizeof(struct pico_dhcpd_settings));
+
+  settings->dev = link->dev;
+  dhcpd_dbg("DHCPD: configuring DHCP server for link %s\n", link->dev->name);
+  settings->my_ip.addr = link->address.addr;
+  dhcpd_dbg("DHCPD: using server addr %X\n", long_be(settings->my_ip.addr));
+  settings->netmask.addr = link->netmask.addr;
+  dhcpd_dbg("DHCPD: using netmask %X\n", long_be(settings->netmask.addr));
+
+  /* default values if not provided */
+  if (settings->pool_start == 0)
+    settings->pool_start = (settings->my_ip.addr & settings->netmask.addr) | POOL_START;
+  dhcpd_dbg("DHCPD: using pool_start %X\n", long_be(settings->pool_start));
+  if (settings->pool_end == 0)
+    settings->pool_end = (settings->my_ip.addr & settings->netmask.addr) | POOL_END;
+  dhcpd_dbg("DHCPD: using pool_end %x\n", long_be(settings->pool_end));
+  if (settings->lease_time == 0)
+    settings->lease_time = LEASE_TIME;
+  dhcpd_dbg("DHCPD: using lease time %x\n", long_be(settings->lease_time));
+  settings->pool_next = settings->pool_start;
+
+  settings->s = pico_socket_open(PICO_PROTO_IPV4, PICO_PROTO_UDP, &pico_dhcpd_wakeup);
+  if (!settings->s) {
+    dhcpd_dbg("DHCP: could not open client socket\n");
+    pico_free(settings);
+    return -1;
+  }
+  if (pico_socket_bind(settings->s, &settings->my_ip, &port) != 0) {
+    dhcpd_dbg("DHCP: could not bind server socket (%s)\n", strerror(pico_err));
+    pico_free(settings);
+    return -1;
+  }
+  
+  if (pico_tree_insert(&DHCPSettings, settings)) {
+    dhcpd_dbg("DHCPD ERROR: link %s already configured\n", link->dev->name);
+    pico_err = PICO_ERR_EINVAL;
+    pico_free(settings);
+    return -1; /* Element key already exists */
+  }
+  dhcpd_dbg("DHCPD: configured DHCP server for link %s\n", link->dev->name);
+
+  return 0;
+}
+#endif /* PICO_SUPPORT_DHCP */