Zeroconf implementation conform to rfc 3927.
Ready for a review
---
gdhcp/gzcip.c | 588 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
gdhcp/gzcip.h | 78 ++++++++
2 files changed, 666 insertions(+), 0 deletions(-)
create mode 100644 gdhcp/gzcip.c
create mode 100644 gdhcp/gzcip.h
diff --git a/gdhcp/gzcip.c b/gdhcp/gzcip.c
new file mode 100644
index 0000000..551298c
--- /dev/null
+++ b/gdhcp/gzcip.c
@@ -0,0 +1,588 @@
+/*
+ *
+ * Zeroconf client library with Glib integration
+ *
+ * Copyright (C) 2010 Aldebaran Robotics. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/time.h>
+#include <arpa/inet.h>
+
+#include <netpacket/packet.h>
+#include <net/ethernet.h>
+#include <net/if_arp.h>
+#include <netinet/if_ether.h>
+
+#include <linux/if.h>
+
+#include <sys/time.h>
+#include <glib.h>
+
+#include "gzcip.h"
+#include "common.h"
+
+/* 169.254.0.0 */
+#define LINKLOCAL_ADDR 0xa9fe0000
+
+typedef enum _listen_mode {
+ L_NONE,
+ L_ARP,
+} ListenMode;
+
+typedef enum _zcip_client_state {
+ PROBE,
+ ANNOUNCE,
+ MONITOR,
+ DEFEND,
+} ClientState;
+
+struct _GZCIPClient {
+ GZCIPType type;
+ ClientState state;
+ int ifindex;
+ uint8_t mac_address[6];
+ struct in_addr requested_ip;
+ struct in_addr null_ip;
+ uint8_t null_addr[6];
+ uint8_t broadcast_addr[6];
+ char* assigned_ip;
+ int sockfd;
+ struct sockaddr_ll saddr;
+ uint8_t retry_times;
+ guint timeout;
+ guint conflicts;
+ ListenMode listen_mode;
+ int listener_sockfd;
+ GIOChannel *listener_channel;
+ guint listener_watch;
+ GZCIPClientEventFunc lease_available_cb;
+ GZCIPClientEventFunc lease_lost_cb;
+ GZCIPClientEventFunc address_conflict_cb;
+ gpointer lease_lost_data;
+ gpointer address_conflict_data;
+ gpointer lease_available_data;
+ GZCIPDebugFunc debug_func;
+ gpointer debug_data;
+};
+
+static gboolean probe_timeout(gpointer zcip_data);
+static gboolean announce_timeout(gpointer zcip_data);
+static gboolean defend_timeout(gpointer zcip_data);
+
+static void out(const char *str, gpointer data)
+{
+ printf("%s", str);
+}
+
+static inline void debug(GZCIPClient *zcip_client, const char *format, ...)
+{
+ char str[256];
+ va_list ap;
+
+ if (zcip_client->debug_func == NULL)
+ return;
+
+ va_start(ap, format);
+
+ if (vsnprintf(str, sizeof(str), format, ap) > 0)
+ zcip_client->debug_func(str, zcip_client->debug_data);
+
+ va_end(ap);
+}
+
+
+/**
+ * Pick a random link local IP address on 169.254/16, except that
+ * the first and last 256 addresses are reserved.
+ *
+ */
+static uint32_t pick(void)
+{
+ unsigned tmp;
+ struct timeval tv;
+ do {
+ gettimeofday(&tv, NULL);
+ srand(tv.tv_usec);
+ tmp = rand();
+ tmp = tmp & IN_CLASSB_HOST;
+ } while (tmp > (IN_CLASSB_HOST - 0x0200));
+ return ((LINKLOCAL_ADDR + 0x0100) + tmp);
+
+}
+ /* static uint32_t pick(void){ */
+ /* uint8_t tmp[4]; */
+ /* uint32_t addr; */
+ /* tmp[3] = 192; */
+ /* tmp[2] = 168; */
+ /* tmp[1] = 1; */
+ /* tmp[0] = 1; */
+
+ /* memcpy(&addr, tmp, sizeof(addr)); */
+ /* return addr; */
+ /* } */
+
+/*
+ * Return a random delay in range of secs
+ */
+static guint random_delay_ms(guint secs)
+{
+ struct timeval tv;
+ guint tmp;
+
+ gettimeofday(&tv, NULL);
+ srand(tv.tv_usec);
+ tmp = rand();
+ return tmp % (secs * 1000);
+}
+
+char *g_zcip_client_get_address(GZCIPClient *zcip_client)
+{
+ return g_strdup(zcip_client->assigned_ip);
+}
+
+char *g_zcip_client_get_netmask(GZCIPClient *zcip_client)
+{
+ return g_strdup("255.255.0.0");
+}
+
+static int zcip_socket(int ifindex)
+{
+ int fd;
+ struct sockaddr_ll sock;
+ fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ARP));
+ if (fd < 0)
+ return fd;
+
+ sock.sll_family = AF_PACKET;
+ sock.sll_protocol = htons(ETH_P_ARP);
+ sock.sll_ifindex = ifindex;
+
+ if (bind(fd, (struct sockaddr *) &sock, sizeof(sock)) != 0) {
+ close(fd);
+ return -errno;
+ }
+
+ return fd;
+}
+
+static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
+ gpointer zcip_data);
+
+static int switch_listening_mode(GZCIPClient *zcip_client,
+ ListenMode listen_mode){
+
+ GIOChannel *listener_channel;
+ int listener_sockfd;
+
+ if (zcip_client->listen_mode == listen_mode)
+ return 0;
+
+ debug(zcip_client, "switching listen from %d to %d\n",
+ zcip_client->listen_mode, listen_mode);
+ if (zcip_client->listen_mode != L_NONE) {
+ g_source_remove(zcip_client->listener_watch);
+ zcip_client->listener_channel = NULL;
+ zcip_client->listen_mode = L_NONE;
+ zcip_client->listener_sockfd = -1;
+ zcip_client->listener_watch = 0;
+ }
+ if (listen_mode == L_NONE)
+ return 0;
+
+ if (listen_mode != L_ARP)
+ return -EIO;
+
+ listener_sockfd = zcip_socket(zcip_client->ifindex);
+
+ if (listener_sockfd < 0)
+ return -EIO;
+
+ listener_channel = g_io_channel_unix_new(listener_sockfd);
+ if (listener_channel == NULL) {
+ close(listener_sockfd);
+ return -EIO;
+ }
+ zcip_client->listen_mode = listen_mode;
+ zcip_client->listener_sockfd = listener_sockfd;
+ zcip_client->listener_channel = listener_channel;
+
+ g_io_channel_set_close_on_unref(listener_channel, TRUE);
+ zcip_client->listener_watch =
+ g_io_add_watch_full(listener_channel,
+ G_PRIORITY_HIGH, G_IO_IN,
+ listener_event, zcip_client,
+ NULL);
+ g_io_channel_unref(zcip_client->listener_channel);
+
+ return 0;
+}
+
+static void arp(GZCIPClient *zcip_client, struct in_addr source_ip,
+ uint8_t *target_eth, struct in_addr target_ip){
+
+ struct ether_arp p;
+ uint32_t ip_source;
+ uint32_t ip_target;
+ ip_source = htonl(source_ip.s_addr);
+ ip_target = htonl(target_ip.s_addr);
+ memset(&p, 0, sizeof(p));
+ // arp request
+ p.arp_hrd = htons(ARPHRD_ETHER);
+ p.arp_pro = htons(ETHERTYPE_IP);
+ p.arp_hln = ETH_ALEN;
+ p.arp_pln = 4;
+ p.arp_op = htons(ARPOP_REQUEST);
+ memcpy(&p.arp_sha, zcip_client->mac_address, ETH_ALEN);
+ memcpy(&p.arp_spa, &ip_source, sizeof(p.arp_spa));
+ memcpy(&p.arp_tha, target_eth, ETH_ALEN);
+ memcpy(&p.arp_tpa, &ip_target, sizeof(p.arp_tpa));
+
+ sendto((zcip_client->sockfd), &p, sizeof(p), 0,
+ (struct sockaddr*) &(zcip_client->saddr),
+ sizeof(zcip_client->saddr));
+}
+
+static gboolean send_probe_packet(gpointer zcip_data)
+{
+ GZCIPClient *zcip_client;
+ guint timeout;
+
+ zcip_client = zcip_data;
+ /*if requested_ip is not valid, pick a new address*/
+ if ( zcip_client->requested_ip.s_addr == 0)
+ {
+ debug(zcip_client, "pick a new address \n");
+ zcip_client->requested_ip.s_addr = pick();
+ }
+
+ debug(zcip_client, "sending probe \n");
+
+ arp(zcip_client, zcip_client->null_ip, zcip_client->null_addr,
+ zcip_client->requested_ip);
+
+ if ( zcip_client->retry_times < 2 )
+ timeout =
+ random_delay_ms(PROBE_MAX-PROBE_MIN) + (PROBE_MIN*1000);
+ else
+ timeout = (ANNOUNCE_WAIT * 1000);
+
+ zcip_client->timeout = g_timeout_add_full(G_PRIORITY_HIGH,
+ timeout,
+ probe_timeout,
+ zcip_client,
+ NULL);
+ switch_listening_mode(zcip_client, L_ARP);
+ zcip_client->retry_times++;
+ return FALSE;
+}
+
+static gboolean send_announce_packet(gpointer zcip_data)
+{
+ GZCIPClient *zcip_client;
+ zcip_client = zcip_data;
+ debug(zcip_client, "sending announce \n");
+ arp(zcip_client, zcip_client->requested_ip, zcip_client->null_addr,
+ zcip_client->requested_ip);
+ if (zcip_client->state == DEFEND){
+ zcip_client->timeout =
+ g_timeout_add_seconds_full(G_PRIORITY_HIGH,
+ DEFEND_INTERVAL,
+ defend_timeout,
+ zcip_client,
+ NULL);
+ return TRUE;
+ }
+ else
+ zcip_client->timeout =
+ g_timeout_add_seconds_full(G_PRIORITY_HIGH,
+ ANNOUNCE_INTERVAL,
+ announce_timeout,
+ zcip_client,
+ NULL);
+ zcip_client->retry_times++;
+ return TRUE;
+}
+
+static int zcip_recv_arp_packet( GZCIPClient *zcip_client ){
+ int bytes;
+ struct ether_arp arp;
+ uint32_t ip_requested;
+ int source_conflict;
+ int target_conflict;
+
+ memset(&arp, 0, sizeof(arp));
+ bytes = 0;
+ bytes = read(zcip_client->listener_sockfd, &arp, sizeof(arp));
+ if (bytes < 0)
+ return -1;
+
+ if ( arp.arp_op != htons(ARPOP_REPLY) &&
+ arp.arp_op != htons(ARPOP_REQUEST)){
+ return -1;
+ }
+
+ ip_requested = ntohl(zcip_client->requested_ip.s_addr);
+
+ source_conflict = memcmp(arp.arp_spa, &ip_requested,
+ sizeof(ip_requested));
+ if (source_conflict != 0){
+ zcip_client->conflicts++;
+ }
+ target_conflict = memcmp(arp.arp_tpa, &ip_requested,
+ sizeof(ip_requested));
+
+ if (source_conflict !=0 && target_conflict != 0)
+ return -1;
+
+ debug(zcip_client, "conflict detected\n");
+ if (zcip_client->state == MONITOR){
+ if (source_conflict != 0)
+ return -1;
+ zcip_client->state = DEFEND;
+ debug(zcip_client, "DEFEND mode conflicts : %d\n",
+ zcip_client->conflicts);
+ send_announce_packet(zcip_client);
+ return 0;
+ }
+ if (zcip_client->state == DEFEND){
+ if (source_conflict != 0)
+ return -1;
+ else if (zcip_client->lease_lost_cb != NULL)
+ zcip_client->lease_lost_cb(zcip_client,
+ zcip_client->lease_lost_data);
+ }
+ g_zcip_client_stop(zcip_client);
+
+ zcip_client->conflicts++;
+ if(zcip_client->conflicts < MAX_CONFLICTS)
+ g_zcip_client_start(zcip_client);
+ else
+ g_timeout_add_seconds(RATE_LIMIT_INTERVAL,
+ g_zcip_client_start,
+ zcip_client);
+ return 0;
+}
+
+static gboolean defend_timeout(gpointer zcip_data)
+{
+ GZCIPClient *zcip_client = zcip_data;
+
+ zcip_client->conflicts = 0;
+ debug(zcip_client, "back to MONITOR mode\n");
+ zcip_client->state = MONITOR;
+ switch_listening_mode(zcip_client, L_ARP);
+
+ return FALSE;
+}
+
+static char *get_ip(uint32_t ip)
+{
+ struct in_addr addr;
+ addr.s_addr = ip;
+ return g_strdup(inet_ntoa(addr));
+}
+
+static gboolean announce_timeout(gpointer zcip_data)
+{
+ GZCIPClient *zcip_client = zcip_data;
+ uint32_t ip;
+
+ debug(zcip_client, "request timeout (retries %d) \n",
+ zcip_client->retry_times);
+
+ if( zcip_client->retry_times != ANNOUNCE_NUM ){
+ send_announce_packet(zcip_client);
+ return FALSE;
+ }
+
+ ip = htonl(zcip_client->requested_ip.s_addr);
+ debug(zcip_client, "switching to monitor mode\n");
+ zcip_client->state = MONITOR;
+ if(zcip_client->assigned_ip == NULL)
+ zcip_client->assigned_ip = get_ip(ip);
+ if (zcip_client->lease_available_cb != NULL)
+ zcip_client->lease_available_cb(zcip_client,
+ zcip_client->lease_available_data);
+ zcip_client->conflicts = 0;
+
+ return FALSE;
+}
+
+static gboolean probe_timeout(gpointer zcip_data)
+{
+
+ GZCIPClient *zcip_client = zcip_data;
+ debug(zcip_client, "request timeout (retries %d) \n",
+ zcip_client->retry_times);
+
+ if( zcip_client->retry_times == PROBE_NUM ) {
+ zcip_client->state = ANNOUNCE;
+ zcip_client->retry_times = 0;
+ send_announce_packet(zcip_client);
+ return FALSE;
+ }
+ send_probe_packet(zcip_client);
+ return FALSE;
+}
+
+static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
+ gpointer zcip_data)
+
+{
+ GZCIPClient *zcip_client = zcip_data;
+ int re;
+
+ if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
+ zcip_client->listener_watch = 0;
+ return TRUE;
+ }
+
+ if (zcip_client->listen_mode == L_NONE)
+ return FALSE;
+
+ if (zcip_client->listener_sockfd < 0){
+ debug(zcip_client, "socket close \n");
+ return -EIO;
+ }
+ if (zcip_client->listen_mode == L_ARP)
+ re = zcip_recv_arp_packet(zcip_client);
+ return TRUE;
+}
+
+gboolean g_zcip_client_start(gpointer zcip_data){
+
+ GZCIPClient *zcip_client = zcip_data;
+ guint timeout;
+
+ debug(zcip_client, "starting zeroconf\n");
+ timeout = random_delay_ms(PROBE_WAIT);
+ g_timeout_add_full(G_PRIORITY_HIGH,
+ timeout,
+ send_probe_packet,
+ zcip_client,
+ NULL);
+
+ return FALSE;
+}
+void g_zcip_client_stop(GZCIPClient *zcip_client){
+
+ debug(zcip_client, "stop zeroconf\n");
+ switch_listening_mode(zcip_client, L_NONE);
+
+ if (zcip_client->timeout > 0) {
+ debug(zcip_client, "removing timeout: %u\n",
+ zcip_client->timeout);
+ g_source_remove(zcip_client->timeout);
+ }
+ zcip_client->timeout = 0;
+
+ if (zcip_client->listener_watch > 0) {
+ g_source_remove(zcip_client->listener_watch);
+ zcip_client->listener_watch = 0;
+ }
+
+ g_free(zcip_client->assigned_ip);
+ zcip_client->assigned_ip = NULL;
+
+ zcip_client->retry_times = 0;
+ zcip_client->requested_ip.s_addr = 0;
+ zcip_client->state = PROBE;
+
+}
+void g_zcip_client_register_event(GZCIPClient *zcip_client,
+ GZCIPClientEvent event,
+ GZCIPClientEventFunc func,
+ gpointer data)
+{
+ switch (event) {
+
+ case G_ZCIP_CLIENT_EVENT_LEASE_AVAILABLE:
+ zcip_client->lease_available_cb = func;
+ zcip_client->lease_available_data = data;
+ return;
+ case G_ZCIP_CLIENT_EVENT_LEASE_LOST:
+ zcip_client->lease_lost_cb = func;
+ zcip_client->lease_lost_data = data;
+ return;
+ }
+}
+
+
+
+GZCIPClient *
+g_zcip_client_new(GZCIPType type, int ifindex, GZCIPClientError *error)
+{
+ GZCIPClient *zcip_client;
+ struct sockaddr_ll saddr;
+
+ if (ifindex < 0) {
+ *error = G_ZCIP_CLIENT_ERROR_INVALID_INDEX;
+ return NULL;
+ }
+
+ zcip_client = g_try_new0(GZCIPClient, 1);
+
+ if (zcip_client == NULL) {
+ *error = G_ZCIP_CLIENT_ERROR_NOMEM;
+ return NULL;
+ }
+
+ if (interface_is_up(ifindex) == FALSE) {
+ *error = G_ZCIP_CLIENT_ERROR_INTERFACE_DOWN;
+ goto error;
+ }
+
+ get_interface_mac_address(ifindex, zcip_client->mac_address);
+ zcip_client->sockfd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ARP));
+
+ if (zcip_client->sockfd < 0){
+ *error = G_ZCIP_CLIENT_ERROR_NOMEM;
+ goto error;
+ }
+
+ saddr.sll_family = AF_PACKET;
+ saddr.sll_protocol = htons(ETH_P_ARP);
+ saddr.sll_ifindex = ifindex;
+ saddr.sll_halen = ETH_ALEN;
+ memset(saddr.sll_addr, 0xFF, ETH_ALEN);
+
+
+ if (bind(zcip_client->sockfd,(struct sockaddr*) &saddr,
+ sizeof(saddr)) < 0){
+ goto error;
+ }
+
+ zcip_client->type = type;
+ zcip_client->ifindex = ifindex;
+ zcip_client->retry_times = 0;
+ zcip_client->state = PROBE;
+ zcip_client->saddr = saddr;
+ *error = G_ZCIP_CLIENT_ERROR_NONE;
+ memset(&(zcip_client->null_ip), 0, sizeof(zcip_client->null_ip));
+ memset(zcip_client->null_addr, 0, ETH_ALEN);
+ memset(zcip_client->broadcast_addr, 0xff, ETH_ALEN);
+ zcip_client->debug_func = &out;
+ return zcip_client;
+ error:
+ g_free(zcip_client);
+ return NULL;
+}
diff --git a/gdhcp/gzcip.h b/gdhcp/gzcip.h
new file mode 100644
index 0000000..c265cfd
--- /dev/null
+++ b/gdhcp/gzcip.h
@@ -0,0 +1,78 @@
+/*
+ *
+ * Zeroconf client library with Glib integration
+ *
+ * Copyright (C) 2010 Aldebaran Robotics. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ */
+
+#ifndef GZCIP_H_
+#define GZCIP_H_
+#include <glib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* See RFC 3927 */
+#define PROBE_WAIT 1
+#define PROBE_NUM 3
+#define PROBE_MIN 1
+#define PROBE_MAX 2
+#define ANNOUNCE_WAIT 2
+#define ANNOUNCE_NUM 2
+#define ANNOUNCE_INTERVAL 2
+#define MAX_CONFLICTS 10
+#define RATE_LIMIT_INTERVAL 60
+#define DEFEND_INTERVAL 10
+
+struct _GZCIPClient;
+
+typedef struct _GZCIPClient GZCIPClient;
+
+typedef enum {
+ G_ZCIP_CLIENT_ERROR_NONE,
+ G_ZCIP_CLIENT_ERROR_INTERFACE_UNAVAILABLE,
+ G_ZCIP_CLIENT_ERROR_INTERFACE_DOWN,
+ G_ZCIP_CLIENT_ERROR_NOMEM,
+ G_ZCIP_CLIENT_ERROR_INVALID_INDEX,
+} GZCIPClientError;
+
+typedef enum {
+ G_ZCIP_CLIENT_EVENT_LEASE_AVAILABLE,
+ G_ZCIP_CLIENT_EVENT_LEASE_LOST,
+} GZCIPClientEvent;
+
+ typedef enum {
+ G_ZCIP_IPV4,
+} GZCIPType;
+
+typedef void (*GZCIPClientEventFunc) (GZCIPClient *client, gpointer user_data);
+typedef void (*GZCIPDebugFunc)(const char *str, gpointer user_data);
+
+GZCIPClient *g_zcip_client_new(GZCIPType type, int ifindex, GZCIPClientError
*error);
+char *g_zcip_client_get_address(GZCIPClient *zcip_client);
+char *g_zcip_client_get_netmask(GZCIPClient *zcip_client);
+gboolean g_zcip_client_start(gpointer zcip_data);
+void g_zcip_client_stop(GZCIPClient *zcip_client);
+void g_zcip_client_register_event(GZCIPClient *zcip_client,
+ GZCIPClientEvent event,
+ GZCIPClientEventFunc func,
+ gpointer data);
+#ifdef __cplusplus
+}
+#endif
+#endif /* !GZCIP_H_ */
--
1.7.1
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