src/libsystemd-network/sd-ipv4ll.c - systemd-stable - Rivoreo Source Code Repositories

 /***
   This file is part of systemd.

   Copyright (C) 2014 Axis Communications AB. All rights reserved.
   Copyright (C) 2015 Tom Gundersen

   systemd is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation; either version 2.1 of the License, or
   (at your option) any later version.

   systemd 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/

 #include <arpa/inet.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 #include "sd-ipv4acd.h"
 #include "sd-ipv4ll.h"

 #include "alloc-util.h"
 #include "ether-addr-util.h"
 #include "in-addr-util.h"
 #include "list.h"
 #include "random-util.h"
 #include "siphash24.h"
 #include "sparse-endian.h"
 #include "string-util.h"
 #include "util.h"

 #define IPV4LL_NETWORK UINT32_C(0xA9FE0000)
 #define IPV4LL_NETMASK UINT32_C(0xFFFF0000)

 #define IPV4LL_DONT_DESTROY(ll) \
         _cleanup_(sd_ipv4ll_unrefp) _unused_ sd_ipv4ll *_dont_destroy_##ll = sd_ipv4ll_ref(ll)

 struct sd_ipv4ll {
         unsigned n_ref;

         sd_ipv4acd *acd;

         be32_t address; /* the address pushed to ACD */
         struct ether_addr mac;

         struct {
                 le64_t value;
                 le64_t generation;
         } seed;
         bool seed_set;

         /* External */
         be32_t claimed_address;

         sd_ipv4ll_callback_t callback;
         void* userdata;
 };

 #define log_ipv4ll_errno(ll, error, fmt, ...) log_internal(LOG_DEBUG, error, __FILE__, __LINE__, __func__, "IPV4LL: " fmt, ##__VA_ARGS__)
 #define log_ipv4ll(ll, fmt, ...) log_ipv4ll_errno(ll, 0, fmt, ##__VA_ARGS__)

 static void ipv4ll_on_acd(sd_ipv4acd *ll, int event, void *userdata);

 sd_ipv4ll *sd_ipv4ll_ref(sd_ipv4ll *ll) {
         if (!ll)
                 return NULL;

         assert(ll->n_ref >= 1);
         ll->n_ref++;

         return ll;
 }

 sd_ipv4ll *sd_ipv4ll_unref(sd_ipv4ll *ll) {
         if (!ll)
                 return NULL;

         assert(ll->n_ref >= 1);
         ll->n_ref--;

         if (ll->n_ref > 0)
                 return NULL;

         sd_ipv4acd_unref(ll->acd);
         return mfree(ll);
 }

 int sd_ipv4ll_new(sd_ipv4ll **ret) {
         _cleanup_(sd_ipv4ll_unrefp) sd_ipv4ll *ll = NULL;
         int r;

         assert_return(ret, -EINVAL);

         ll = new0(sd_ipv4ll, 1);
         if (!ll)
                 return -ENOMEM;

         ll->n_ref = 1;

         r = sd_ipv4acd_new(&ll->acd);
         if (r < 0)
                 return r;

         r = sd_ipv4acd_set_callback(ll->acd, ipv4ll_on_acd, ll);
         if (r < 0)
                 return r;

         *ret = ll;
         ll = NULL;

         return 0;
 }

 int sd_ipv4ll_stop(sd_ipv4ll *ll) {
         assert_return(ll, -EINVAL);

         return sd_ipv4acd_stop(ll->acd);
 }

 int sd_ipv4ll_set_ifindex(sd_ipv4ll *ll, int ifindex) {
         assert_return(ll, -EINVAL);
         assert_return(ifindex > 0, -EINVAL);
         assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);

         return sd_ipv4acd_set_ifindex(ll->acd, ifindex);
 }

 int sd_ipv4ll_set_mac(sd_ipv4ll *ll, const struct ether_addr *addr) {
         int r;

         assert_return(ll, -EINVAL);
         assert_return(addr, -EINVAL);
         assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);

         r = sd_ipv4acd_set_mac(ll->acd, addr);
         if (r < 0)
                 return r;

         ll->mac = *addr;
         return 0;
 }

 int sd_ipv4ll_detach_event(sd_ipv4ll *ll) {
         assert_return(ll, -EINVAL);

         return sd_ipv4acd_detach_event(ll->acd);
 }

 int sd_ipv4ll_attach_event(sd_ipv4ll *ll, sd_event *event, int64_t priority) {
         assert_return(ll, -EINVAL);

         return sd_ipv4acd_attach_event(ll->acd, event, priority);
 }

 int sd_ipv4ll_set_callback(sd_ipv4ll *ll, sd_ipv4ll_callback_t cb, void *userdata) {
         assert_return(ll, -EINVAL);

         ll->callback = cb;
         ll->userdata = userdata;

         return 0;
 }

 int sd_ipv4ll_get_address(sd_ipv4ll *ll, struct in_addr *address) {
         assert_return(ll, -EINVAL);
         assert_return(address, -EINVAL);

         if (ll->claimed_address == 0)
                 return -ENOENT;

         address->s_addr = ll->claimed_address;

         return 0;
 }

 int sd_ipv4ll_set_address_seed(sd_ipv4ll *ll, uint64_t seed) {
         assert_return(ll, -EINVAL);
         assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);

         ll->seed.value = htole64(seed);
         ll->seed_set = true;

         return 0;
 }

 int sd_ipv4ll_is_running(sd_ipv4ll *ll) {
         assert_return(ll, false);

         return sd_ipv4acd_is_running(ll->acd);
 }

 static bool ipv4ll_address_is_valid(const struct in_addr *address) {
         assert(address);

         if (!in_addr_is_link_local(AF_INET, (const union in_addr_union *) address))
                 return false;

         return !IN_SET(be32toh(address->s_addr) & 0x0000FF00U, 0x0000U, 0xFF00U);
 }

 int sd_ipv4ll_set_address(sd_ipv4ll *ll, const struct in_addr *address) {
         int r;

         assert_return(ll, -EINVAL);
         assert_return(address, -EINVAL);
         assert_return(ipv4ll_address_is_valid(address), -EINVAL);

         r = sd_ipv4acd_set_address(ll->acd, address);
         if (r < 0)
                 return r;

         ll->address = address->s_addr;

         return 0;
 }

 #define PICK_HASH_KEY SD_ID128_MAKE(15,ac,82,a6,d6,3f,49,78,98,77,5d,0c,69,02,94,0b)

 static int ipv4ll_pick_address(sd_ipv4ll *ll) {
         _cleanup_free_ char *address = NULL;
         be32_t addr;

         assert(ll);

         do {
                 uint64_t h;

                 h = siphash24(&ll->seed, sizeof(ll->seed), PICK_HASH_KEY.bytes);

                 /* Increase the generation counter by one */
                 ll->seed.generation = htole64(le64toh(ll->seed.generation) + 1);

                 addr = htobe32((h & UINT32_C(0x0000FFFF)) | IPV4LL_NETWORK);
         } while (addr == ll->address ||
                  IN_SET(be32toh(addr) & 0x0000FF00U, 0x0000U, 0xFF00U));

         (void) in_addr_to_string(AF_INET, &(union in_addr_union) { .in.s_addr = addr }, &address);
         log_ipv4ll(ll, "Picked new IP address %s.", strna(address));

         return sd_ipv4ll_set_address(ll, &(struct in_addr) { addr });
 }

 #define MAC_HASH_KEY SD_ID128_MAKE(df,04,22,98,3f,ad,14,52,f9,87,2e,d1,9c,70,e2,f2)

 int sd_ipv4ll_start(sd_ipv4ll *ll) {
         int r;
         bool picked_address = false;

         assert_return(ll, -EINVAL);
         assert_return(!ether_addr_is_null(&ll->mac), -EINVAL);
         assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);

         /* If no random seed is set, generate some from the MAC address */
         if (!ll->seed_set)
                 ll->seed.value = htole64(siphash24(ll->mac.ether_addr_octet, ETH_ALEN, MAC_HASH_KEY.bytes));

         /* Restart the generation counter. */
         ll->seed.generation = 0;

         if (ll->address == 0) {
                 r = ipv4ll_pick_address(ll);
                 if (r < 0)
                         return r;

                 picked_address = true;
         }

         r = sd_ipv4acd_start(ll->acd);
         if (r < 0) {

                 /* We couldn't start? If so, let's forget the picked address again, the user might make a change and
                  * retry, and we want the new data to take effect when picking an address. */
                 if (picked_address)
                         ll->address = 0;

                 return r;
         }

         return 0;
 }

 static void ipv4ll_client_notify(sd_ipv4ll *ll, int event) {
         assert(ll);

         if (ll->callback)
                 ll->callback(ll, event, ll->userdata);
 }

 void ipv4ll_on_acd(sd_ipv4acd *acd, int event, void *userdata) {
         sd_ipv4ll *ll = userdata;
         IPV4LL_DONT_DESTROY(ll);
         int r;

         assert(acd);
         assert(ll);

         switch (event) {

         case SD_IPV4ACD_EVENT_STOP:
                 ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_STOP);
                 ll->claimed_address = 0;
                 break;

         case SD_IPV4ACD_EVENT_BIND:
                 ll->claimed_address = ll->address;
                 ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_BIND);
                 break;

         case SD_IPV4ACD_EVENT_CONFLICT:
                 /* if an address was already bound we must call up to the
                    user to handle this, otherwise we just try again */
                 if (ll->claimed_address != 0) {
                         ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_CONFLICT);

                         ll->claimed_address = 0;
                 } else {
                         r = ipv4ll_pick_address(ll);
                         if (r < 0)
                                 goto error;

                         r = sd_ipv4acd_start(ll->acd);
                         if (r < 0)
                                 goto error;
                 }

                 break;

         default:
                 assert_not_reached("Invalid IPv4ACD event.");
         }

         return;

 error:
         ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_STOP);
 }
	/***
	This file is part of systemd.

	Copyright (C) 2014 Axis Communications AB. All rights reserved.
	Copyright (C) 2015 Tom Gundersen

	systemd is free software; you can redistribute it and/or modify it
	under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation; either version 2.1 of the License, or
	(at your option) any later version.

	systemd 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
	Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	***/

	#include <arpa/inet.h>
	#include <errno.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>

	#include "sd-ipv4acd.h"
	#include "sd-ipv4ll.h"

	#include "alloc-util.h"
	#include "ether-addr-util.h"
	#include "in-addr-util.h"
	#include "list.h"
	#include "random-util.h"
	#include "siphash24.h"
	#include "sparse-endian.h"
	#include "string-util.h"
	#include "util.h"

	#define IPV4LL_NETWORK UINT32_C(0xA9FE0000)
	#define IPV4LL_NETMASK UINT32_C(0xFFFF0000)

	#define IPV4LL_DONT_DESTROY(ll) \
	_cleanup_(sd_ipv4ll_unrefp) _unused_ sd_ipv4ll *_dont_destroy_##ll = sd_ipv4ll_ref(ll)

	struct sd_ipv4ll {
	unsigned n_ref;

	sd_ipv4acd *acd;

	be32_t address; /* the address pushed to ACD */
	struct ether_addr mac;

	struct {
	le64_t value;
	le64_t generation;
	} seed;
	bool seed_set;

	/* External */
	be32_t claimed_address;

	sd_ipv4ll_callback_t callback;
	void* userdata;
	};

	#define log_ipv4ll_errno(ll, error, fmt, ...) log_internal(LOG_DEBUG, error, __FILE__, __LINE__, __func__, "IPV4LL: " fmt, ##__VA_ARGS__)
	#define log_ipv4ll(ll, fmt, ...) log_ipv4ll_errno(ll, 0, fmt, ##__VA_ARGS__)

	static void ipv4ll_on_acd(sd_ipv4acd ll, int event, void userdata);

	sd_ipv4ll sd_ipv4ll_ref(sd_ipv4ll ll) {
	if (!ll)
	return NULL;

	assert(ll->n_ref >= 1);
	ll->n_ref++;

	return ll;
	}

	sd_ipv4ll sd_ipv4ll_unref(sd_ipv4ll ll) {
	if (!ll)
	return NULL;

	assert(ll->n_ref >= 1);
	ll->n_ref--;

	if (ll->n_ref > 0)
	return NULL;

	sd_ipv4acd_unref(ll->acd);
	return mfree(ll);
	}

	int sd_ipv4ll_new(sd_ipv4ll **ret) {
	_cleanup_(sd_ipv4ll_unrefp) sd_ipv4ll *ll = NULL;
	int r;

	assert_return(ret, -EINVAL);

	ll = new0(sd_ipv4ll, 1);
	if (!ll)
	return -ENOMEM;

	ll->n_ref = 1;

	r = sd_ipv4acd_new(&ll->acd);
	if (r < 0)
	return r;

	r = sd_ipv4acd_set_callback(ll->acd, ipv4ll_on_acd, ll);
	if (r < 0)
	return r;

	*ret = ll;
	ll = NULL;

	return 0;
	}

	int sd_ipv4ll_stop(sd_ipv4ll *ll) {
	assert_return(ll, -EINVAL);

	return sd_ipv4acd_stop(ll->acd);
	}

	int sd_ipv4ll_set_ifindex(sd_ipv4ll *ll, int ifindex) {
	assert_return(ll, -EINVAL);
	assert_return(ifindex > 0, -EINVAL);
	assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);

	return sd_ipv4acd_set_ifindex(ll->acd, ifindex);
	}

	int sd_ipv4ll_set_mac(sd_ipv4ll ll, const struct ether_addr addr) {
	int r;

	assert_return(ll, -EINVAL);
	assert_return(addr, -EINVAL);
	assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);

	r = sd_ipv4acd_set_mac(ll->acd, addr);
	if (r < 0)
	return r;

	ll->mac = *addr;
	return 0;
	}

	int sd_ipv4ll_detach_event(sd_ipv4ll *ll) {
	assert_return(ll, -EINVAL);

	return sd_ipv4acd_detach_event(ll->acd);
	}

	int sd_ipv4ll_attach_event(sd_ipv4ll ll, sd_event event, int64_t priority) {
	assert_return(ll, -EINVAL);

	return sd_ipv4acd_attach_event(ll->acd, event, priority);
	}

	int sd_ipv4ll_set_callback(sd_ipv4ll ll, sd_ipv4ll_callback_t cb, void userdata) {
	assert_return(ll, -EINVAL);

	ll->callback = cb;
	ll->userdata = userdata;

	return 0;
	}

	int sd_ipv4ll_get_address(sd_ipv4ll ll, struct in_addr address) {
	assert_return(ll, -EINVAL);
	assert_return(address, -EINVAL);

	if (ll->claimed_address == 0)
	return -ENOENT;

	address->s_addr = ll->claimed_address;

	return 0;
	}

	int sd_ipv4ll_set_address_seed(sd_ipv4ll *ll, uint64_t seed) {
	assert_return(ll, -EINVAL);
	assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);

	ll->seed.value = htole64(seed);
	ll->seed_set = true;

	return 0;
	}

	int sd_ipv4ll_is_running(sd_ipv4ll *ll) {
	assert_return(ll, false);

	return sd_ipv4acd_is_running(ll->acd);
	}

	static bool ipv4ll_address_is_valid(const struct in_addr *address) {
	assert(address);

	if (!in_addr_is_link_local(AF_INET, (const union in_addr_union *) address))
	return false;

	return !IN_SET(be32toh(address->s_addr) & 0x0000FF00U, 0x0000U, 0xFF00U);
	}

	int sd_ipv4ll_set_address(sd_ipv4ll ll, const struct in_addr address) {
	int r;

	assert_return(ll, -EINVAL);
	assert_return(address, -EINVAL);
	assert_return(ipv4ll_address_is_valid(address), -EINVAL);

	r = sd_ipv4acd_set_address(ll->acd, address);
	if (r < 0)
	return r;

	ll->address = address->s_addr;

	return 0;
	}

	#define PICK_HASH_KEY SD_ID128_MAKE(15,ac,82,a6,d6,3f,49,78,98,77,5d,0c,69,02,94,0b)

	static int ipv4ll_pick_address(sd_ipv4ll *ll) {
	_cleanup_free_ char *address = NULL;
	be32_t addr;

	assert(ll);

	do {
	uint64_t h;

	h = siphash24(&ll->seed, sizeof(ll->seed), PICK_HASH_KEY.bytes);

	/* Increase the generation counter by one */
	ll->seed.generation = htole64(le64toh(ll->seed.generation) + 1);

	addr = htobe32((h & UINT32_C(0x0000FFFF)) \| IPV4LL_NETWORK);
	} while (addr == ll->address \|\|
	IN_SET(be32toh(addr) & 0x0000FF00U, 0x0000U, 0xFF00U));

	(void) in_addr_to_string(AF_INET, &(union in_addr_union) { .in.s_addr = addr }, &address);
	log_ipv4ll(ll, "Picked new IP address %s.", strna(address));

	return sd_ipv4ll_set_address(ll, &(struct in_addr) { addr });
	}

	#define MAC_HASH_KEY SD_ID128_MAKE(df,04,22,98,3f,ad,14,52,f9,87,2e,d1,9c,70,e2,f2)

	int sd_ipv4ll_start(sd_ipv4ll *ll) {
	int r;
	bool picked_address = false;

	assert_return(ll, -EINVAL);
	assert_return(!ether_addr_is_null(&ll->mac), -EINVAL);
	assert_return(sd_ipv4ll_is_running(ll) == 0, -EBUSY);

	/* If no random seed is set, generate some from the MAC address */
	if (!ll->seed_set)
	ll->seed.value = htole64(siphash24(ll->mac.ether_addr_octet, ETH_ALEN, MAC_HASH_KEY.bytes));

	/* Restart the generation counter. */
	ll->seed.generation = 0;

	if (ll->address == 0) {
	r = ipv4ll_pick_address(ll);
	if (r < 0)
	return r;

	picked_address = true;
	}

	r = sd_ipv4acd_start(ll->acd);
	if (r < 0) {

	/* We couldn't start? If so, let's forget the picked address again, the user might make a change and
	* retry, and we want the new data to take effect when picking an address. */
	if (picked_address)
	ll->address = 0;

	return r;
	}

	return 0;
	}

	static void ipv4ll_client_notify(sd_ipv4ll *ll, int event) {
	assert(ll);

	if (ll->callback)
	ll->callback(ll, event, ll->userdata);
	}

	void ipv4ll_on_acd(sd_ipv4acd acd, int event, void userdata) {
	sd_ipv4ll *ll = userdata;
	IPV4LL_DONT_DESTROY(ll);
	int r;

	assert(acd);
	assert(ll);

	switch (event) {

	case SD_IPV4ACD_EVENT_STOP:
	ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_STOP);
	ll->claimed_address = 0;
	break;

	case SD_IPV4ACD_EVENT_BIND:
	ll->claimed_address = ll->address;
	ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_BIND);
	break;

	case SD_IPV4ACD_EVENT_CONFLICT:
	/* if an address was already bound we must call up to the
	user to handle this, otherwise we just try again */
	if (ll->claimed_address != 0) {
	ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_CONFLICT);

	ll->claimed_address = 0;
	} else {
	r = ipv4ll_pick_address(ll);
	if (r < 0)
	goto error;

	r = sd_ipv4acd_start(ll->acd);
	if (r < 0)
	goto error;
	}

	break;

	default:
	assert_not_reached("Invalid IPv4ACD event.");
	}

	return;

	error:
	ipv4ll_client_notify(ll, SD_IPV4LL_EVENT_STOP);
	}