From e3dca0089b7b50e2ec21409d1292727921d06102 Mon Sep 17 00:00:00 2001 From: Tom Gundersen Date: Fri, 21 Aug 2015 12:50:31 +0200 Subject: sd-ipv4acd: introduce new library split out from sd-ipv4ll This splits the Address Conflict Detection out of the Link Local library so that we can reuse it for DHCP and static addresses in the future. Implements RFC5227. --- src/libsystemd-network/sd-ipv4ll.c | 568 ++++++++++--------------------------- 1 file changed, 145 insertions(+), 423 deletions(-) (limited to 'src/libsystemd-network/sd-ipv4ll.c') diff --git a/src/libsystemd-network/sd-ipv4ll.c b/src/libsystemd-network/sd-ipv4ll.c index 03a9b3f4f4..f0230b919c 100644 --- a/src/libsystemd-network/sd-ipv4ll.c +++ b/src/libsystemd-network/sd-ipv4ll.c @@ -24,65 +24,33 @@ #include #include -#include "util.h" -#include "siphash24.h" +#include "event-util.h" #include "list.h" #include "random-util.h" -#include "event-util.h" +#include "refcnt.h" +#include "siphash24.h" +#include "sparse-endian.h" +#include "util.h" -#include "arp-util.h" +#include "sd-ipv4acd.h" #include "sd-ipv4ll.h" -/* Constants from the RFC */ -#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 - #define IPV4LL_NETWORK 0xA9FE0000L #define IPV4LL_NETMASK 0xFFFF0000L -#define log_ipv4ll(ll, fmt, ...) log_internal(LOG_DEBUG, 0, __FILE__, __LINE__, __func__, "IPv4LL: " fmt, ##__VA_ARGS__) - #define IPV4LL_DONT_DESTROY(ll) \ _cleanup_ipv4ll_unref_ _unused_ sd_ipv4ll *_dont_destroy_##ll = sd_ipv4ll_ref(ll) -typedef enum IPv4LLState { - IPV4LL_STATE_INIT, - IPV4LL_STATE_WAITING_PROBE, - IPV4LL_STATE_PROBING, - IPV4LL_STATE_WAITING_ANNOUNCE, - IPV4LL_STATE_ANNOUNCING, - IPV4LL_STATE_RUNNING, - _IPV4LL_STATE_MAX, - _IPV4LL_STATE_INVALID = -1 -} IPv4LLState; - struct sd_ipv4ll { unsigned n_ref; - IPv4LLState state; - int index; - int fd; - int iteration; - int conflict; - sd_event_source *receive_message; - sd_event_source *timer; - usec_t defend_window; - be32_t address; + sd_ipv4acd *acd; + be32_t address; /* the address pushed to ACD */ struct random_data *random_data; char *random_data_state; + /* External */ be32_t claimed_address; - struct ether_addr mac_addr; - sd_event *event; - int event_priority; sd_ipv4ll_cb_t cb; void* userdata; }; @@ -107,12 +75,7 @@ sd_ipv4ll *sd_ipv4ll_unref(sd_ipv4ll *ll) { if (ll->n_ref > 0) return NULL; - ll->receive_message = sd_event_source_unref(ll->receive_message); - ll->fd = safe_close(ll->fd); - - ll->timer = sd_event_source_unref(ll->timer); - - sd_ipv4ll_detach_event(ll); + sd_ipv4acd_unref(ll->acd); free(ll->random_data); free(ll->random_data_state); @@ -124,8 +87,11 @@ sd_ipv4ll *sd_ipv4ll_unref(sd_ipv4ll *ll) { DEFINE_TRIVIAL_CLEANUP_FUNC(sd_ipv4ll*, sd_ipv4ll_unref); #define _cleanup_ipv4ll_unref_ _cleanup_(sd_ipv4ll_unrefp) +static void ipv4ll_on_acd(sd_ipv4acd *ll, int event, void *userdata); + int sd_ipv4ll_new(sd_ipv4ll **ret) { _cleanup_ipv4ll_unref_ sd_ipv4ll *ll = NULL; + int r; assert_return(ret, -EINVAL); @@ -133,10 +99,15 @@ int sd_ipv4ll_new(sd_ipv4ll **ret) { if (!ll) return -ENOMEM; + 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; + ll->n_ref = 1; - ll->state = IPV4LL_STATE_INIT; - ll->index = -1; - ll->fd = -1; *ret = ll; ll = NULL; @@ -144,347 +115,62 @@ int sd_ipv4ll_new(sd_ipv4ll **ret) { return 0; } -static void ipv4ll_set_state(sd_ipv4ll *ll, IPv4LLState st, bool reset_counter) { - - assert(ll); - assert(st < _IPV4LL_STATE_MAX); - - if (st == ll->state && !reset_counter) { - ll->iteration++; - } else { - ll->state = st; - ll->iteration = 0; - } -} - -static void ipv4ll_client_notify(sd_ipv4ll *ll, int event) { - assert(ll); - - if (ll->cb) - ll->cb(ll, event, ll->userdata); -} - -static void ipv4ll_stop(sd_ipv4ll *ll) { - IPV4LL_DONT_DESTROY(ll); - - assert(ll); - - ll->receive_message = sd_event_source_unref(ll->receive_message); - ll->fd = safe_close(ll->fd); - - ll->timer = sd_event_source_unref(ll->timer); - - log_ipv4ll(ll, "STOPPED"); - - ll->claimed_address = 0; - ipv4ll_set_state (ll, IPV4LL_STATE_INIT, true); -} - int sd_ipv4ll_stop(sd_ipv4ll *ll) { - IPV4LL_DONT_DESTROY(ll); - - assert_return(ll, -EINVAL); - - ipv4ll_stop(ll); - - ipv4ll_client_notify(ll, IPV4LL_EVENT_STOP); - - return 0; -} - -static int ipv4ll_pick_address(sd_ipv4ll *ll, be32_t *address) { - be32_t addr; - int r; - int32_t random; - - assert(ll); - assert(address); - assert(ll->random_data); - - do { - r = random_r(ll->random_data, &random); - if (r < 0) - return r; - addr = htonl((random & 0x0000FFFF) | IPV4LL_NETWORK); - } while (addr == ll->address || - (ntohl(addr) & IPV4LL_NETMASK) != IPV4LL_NETWORK || - (ntohl(addr) & 0x0000FF00) == 0x0000 || - (ntohl(addr) & 0x0000FF00) == 0xFF00); - - *address = addr; - return 0; -} - -static int ipv4ll_on_timeout(sd_event_source *s, uint64_t usec, void *userdata); - -static int ipv4ll_set_next_wakeup(sd_ipv4ll *ll, int sec, int random_sec) { - _cleanup_event_source_unref_ sd_event_source *timer = NULL; - usec_t next_timeout; - usec_t time_now; int r; - assert(sec >= 0); - assert(random_sec >= 0); - assert(ll); - - next_timeout = sec * USEC_PER_SEC; - - if (random_sec) - next_timeout += random_u32() % (random_sec * USEC_PER_SEC); - - assert_se(sd_event_now(ll->event, clock_boottime_or_monotonic(), &time_now) >= 0); - - r = sd_event_add_time(ll->event, &timer, clock_boottime_or_monotonic(), - time_now + next_timeout, 0, ipv4ll_on_timeout, ll); - if (r < 0) - return r; - - r = sd_event_source_set_priority(timer, ll->event_priority); - if (r < 0) - return r; + assert_return(ll, -EINVAL); - r = sd_event_source_set_description(timer, "ipv4ll-timer"); + r = sd_ipv4acd_stop(ll->acd); if (r < 0) return r; - ll->timer = sd_event_source_unref(ll->timer); - ll->timer = timer; - timer = NULL; - return 0; } -static bool ipv4ll_arp_conflict(sd_ipv4ll *ll, struct ether_arp *arp) { - assert(ll); - assert(arp); - - /* see the BPF */ - if (memcmp(arp->arp_spa, &ll->address, sizeof(ll->address)) == 0) - return true; +int sd_ipv4ll_set_index(sd_ipv4ll *ll, int interface_index) { + assert_return(ll, -EINVAL); - /* the TPA matched instead of the SPA, this is not a conflict */ - return false; + return sd_ipv4acd_set_index(ll->acd, interface_index); } -static int ipv4ll_on_timeout(sd_event_source *s, uint64_t usec, void *userdata) { - sd_ipv4ll *ll = userdata; - int r = 0; - - assert(ll); - - switch (ll->state) { - case IPV4LL_STATE_INIT: - - log_ipv4ll(ll, "PROBE"); - - ipv4ll_set_state(ll, IPV4LL_STATE_WAITING_PROBE, true); - - if (ll->conflict >= MAX_CONFLICTS) { - log_ipv4ll(ll, "MAX_CONFLICTS"); - r = ipv4ll_set_next_wakeup(ll, RATE_LIMIT_INTERVAL, PROBE_WAIT); - if (r < 0) - return r; - } else { - r = ipv4ll_set_next_wakeup(ll, 0, PROBE_WAIT); - if (r < 0) - return r; - } - - break; - case IPV4LL_STATE_WAITING_PROBE: - case IPV4LL_STATE_PROBING: - /* Send a probe */ - r = arp_send_probe(ll->fd, ll->index, ll->address, &ll->mac_addr); - if (r < 0) { - log_ipv4ll(ll, "Failed to send ARP probe."); - goto out; - } - - if (ll->iteration < PROBE_NUM - 2) { - ipv4ll_set_state(ll, IPV4LL_STATE_PROBING, false); - - r = ipv4ll_set_next_wakeup(ll, PROBE_MIN, (PROBE_MAX-PROBE_MIN)); - if (r < 0) - goto out; - } else { - ipv4ll_set_state(ll, IPV4LL_STATE_WAITING_ANNOUNCE, true); - - r = ipv4ll_set_next_wakeup(ll, ANNOUNCE_WAIT, 0); - if (r < 0) - goto out; - } - - break; - - case IPV4LL_STATE_ANNOUNCING: - if (ll->iteration >= ANNOUNCE_NUM - 1) { - ipv4ll_set_state(ll, IPV4LL_STATE_RUNNING, false); - - break; - } - case IPV4LL_STATE_WAITING_ANNOUNCE: - /* Send announcement packet */ - r = arp_send_announcement(ll->fd, ll->index, ll->address, &ll->mac_addr); - if (r < 0) { - log_ipv4ll(ll, "Failed to send ARP announcement."); - goto out; - } - - ipv4ll_set_state(ll, IPV4LL_STATE_ANNOUNCING, false); - - r = ipv4ll_set_next_wakeup(ll, ANNOUNCE_INTERVAL, 0); - if (r < 0) - goto out; - - if (ll->iteration == 0) { - log_ipv4ll(ll, "ANNOUNCE"); - ll->claimed_address = ll->address; - ipv4ll_client_notify(ll, IPV4LL_EVENT_BIND); - ll->conflict = 0; - } - - break; - default: - assert_not_reached("Invalid state."); - } - -out: - if (r < 0 && ll) - sd_ipv4ll_stop(ll); - - return 1; -} +#define HASH_KEY SD_ID128_MAKE(df,04,22,98,3f,ad,14,52,f9,87,2e,d1,9c,70,e2,f2) -static int ipv4ll_on_conflict(sd_ipv4ll *ll) { - IPV4LL_DONT_DESTROY(ll); +int sd_ipv4ll_set_mac(sd_ipv4ll *ll, const struct ether_addr *addr) { int r; - assert(ll); - - log_ipv4ll(ll, "CONFLICT"); - - ll->conflict++; - - ipv4ll_client_notify(ll, IPV4LL_EVENT_CONFLICT); - - sd_ipv4ll_stop(ll); - - /* Pick a new address */ - r = ipv4ll_pick_address(ll, &ll->address); - if (r < 0) - return r; - - r = sd_ipv4ll_start(ll); - if (r < 0) - return r; + assert_return(ll, -EINVAL); - return 0; -} + if (!ll->random_data) { + uint8_t seed[8]; -static int ipv4ll_on_packet(sd_event_source *s, int fd, - uint32_t revents, void *userdata) { - sd_ipv4ll *ll = userdata; - struct ether_arp packet; - int r; + /* If no random data is set, generate some from the MAC */ + siphash24(seed, &addr->ether_addr_octet, + ETH_ALEN, HASH_KEY.bytes); - assert(ll); - assert(fd >= 0); - - r = read(fd, &packet, sizeof(struct ether_arp)); - if (r < (int) sizeof(struct ether_arp)) - goto out; - - switch (ll->state) { - case IPV4LL_STATE_ANNOUNCING: - case IPV4LL_STATE_RUNNING: - if (ipv4ll_arp_conflict(ll, &packet)) { - usec_t ts; - - assert_se(sd_event_now(ll->event, clock_boottime_or_monotonic(), &ts) >= 0); - - /* Defend address */ - if (ts > ll->defend_window) { - ll->defend_window = ts + DEFEND_INTERVAL * USEC_PER_SEC; - r = arp_send_announcement(ll->fd, ll->index, ll->address, &ll->mac_addr); - if (r < 0) { - log_ipv4ll(ll, "Failed to send ARP announcement."); - goto out; - } - - } else { - r = ipv4ll_on_conflict(ll); - if (r < 0) - goto out; - } - } + assert_cc(sizeof(unsigned) <= 8); - break; - case IPV4LL_STATE_WAITING_PROBE: - case IPV4LL_STATE_PROBING: - case IPV4LL_STATE_WAITING_ANNOUNCE: - /* BPF ensures this packet indicates a conflict */ - r = ipv4ll_on_conflict(ll); + r = sd_ipv4ll_set_address_seed(ll, *(unsigned*)seed); if (r < 0) - goto out; - - break; - default: - assert_not_reached("Invalid state."); + return r; } -out: - if (r < 0 && ll) - sd_ipv4ll_stop(ll); - - return 1; -} - -int sd_ipv4ll_set_index(sd_ipv4ll *ll, int interface_index) { - assert_return(ll, -EINVAL); - assert_return(interface_index > 0, -EINVAL); - assert_return(ll->state == IPV4LL_STATE_INIT, -EBUSY); - - ll->index = interface_index; - - return 0; -} - -int sd_ipv4ll_set_mac(sd_ipv4ll *ll, const struct ether_addr *addr) { - assert_return(ll, -EINVAL); - assert_return(addr, -EINVAL); - assert_return(ll->state == IPV4LL_STATE_INIT, -EBUSY); - - if (memcmp(&ll->mac_addr, addr, ETH_ALEN) == 0) - return 0; - - memcpy(&ll->mac_addr, addr, ETH_ALEN); - - return 0; + return sd_ipv4acd_set_mac(ll->acd, addr); } int sd_ipv4ll_detach_event(sd_ipv4ll *ll) { assert_return(ll, -EINVAL); - ll->event = sd_event_unref(ll->event); - - return 0; + return sd_ipv4acd_detach_event(ll->acd); } int sd_ipv4ll_attach_event(sd_ipv4ll *ll, sd_event *event, int priority) { int r; assert_return(ll, -EINVAL); - assert_return(!ll->event, -EBUSY); - - if (event) - ll->event = sd_event_ref(event); - else { - r = sd_event_default(&ll->event); - if (r < 0) - return r; - } - ll->event_priority = priority; + r = sd_ipv4acd_attach_event(ll->acd, event, priority); + if (r < 0) + return r; return 0; } @@ -506,111 +192,147 @@ int sd_ipv4ll_get_address(sd_ipv4ll *ll, struct in_addr *address){ return -ENOENT; address->s_addr = ll->claimed_address; + return 0; } -int sd_ipv4ll_set_address_seed(sd_ipv4ll *ll, uint8_t seed[8]) { - unsigned int entropy; +int sd_ipv4ll_set_address_seed(sd_ipv4ll *ll, unsigned seed) { + _cleanup_free_ struct random_data *random_data = NULL; + _cleanup_free_ char *random_data_state = NULL; int r; assert_return(ll, -EINVAL); assert_return(seed, -EINVAL); - entropy = *seed; + random_data = new0(struct random_data, 1); + if (!random_data) + return -ENOMEM; - free(ll->random_data); - free(ll->random_data_state); + random_data_state = new0(char, 128); + if (!random_data_state) + return -ENOMEM; - ll->random_data = new0(struct random_data, 1); - ll->random_data_state = new0(char, 128); + r = initstate_r(seed, random_data_state, 128, random_data); + if (r < 0) + return r; - if (!ll->random_data || !ll->random_data_state) { - r = -ENOMEM; - goto error; - } + free(ll->random_data); + ll->random_data = random_data; + random_data = NULL; - r = initstate_r((unsigned int)entropy, ll->random_data_state, 128, ll->random_data); - if (r < 0) - goto error; + free(ll->random_data_state); + ll->random_data_state = random_data_state; + random_data_state = NULL; -error: - if (r < 0){ - free(ll->random_data); - free(ll->random_data_state); - ll->random_data = NULL; - ll->random_data_state = NULL; - } - return r; + return 0; } bool sd_ipv4ll_is_running(sd_ipv4ll *ll) { assert_return(ll, false); - return ll->state != IPV4LL_STATE_INIT; + return sd_ipv4acd_is_running(ll->acd); } -#define 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) { +static int ipv4ll_pick_address(sd_ipv4ll *ll) { + struct in_addr in_addr; + be32_t addr; int r; + int32_t random; - assert_return(ll, -EINVAL); - assert_return(ll->event, -EINVAL); - assert_return(ll->index > 0, -EINVAL); - assert_return(ll->state == IPV4LL_STATE_INIT, -EBUSY); + assert(ll); + assert(ll->random_data); - ll->state = IPV4LL_STATE_INIT; + do { + r = random_r(ll->random_data, &random); + if (r < 0) + return r; + addr = htonl((random & 0x0000FFFF) | IPV4LL_NETWORK); + } while (addr == ll->address || + (ntohl(addr) & IPV4LL_NETMASK) != IPV4LL_NETWORK || + (ntohl(addr) & 0x0000FF00) == 0x0000 || + (ntohl(addr) & 0x0000FF00) == 0xFF00); - ll->conflict = 0; - ll->defend_window = 0; - ll->claimed_address = 0; + in_addr.s_addr = addr; - if (!ll->random_data) { - uint8_t seed[8]; + r = sd_ipv4acd_set_address(ll->acd, &in_addr); + if (r < 0) + return r; - /* Fallback to mac */ - siphash24(seed, &ll->mac_addr.ether_addr_octet, - ETH_ALEN, HASH_KEY.bytes); + ll->address = addr; - r = sd_ipv4ll_set_address_seed(ll, seed); - if (r < 0) - goto out; - } + return 0; +} + +int sd_ipv4ll_start(sd_ipv4ll *ll) { + int r; + + assert_return(ll, -EINVAL); + assert_return(ll->random_data, -EINVAL); if (ll->address == 0) { - r = ipv4ll_pick_address(ll, &ll->address); + r = ipv4ll_pick_address(ll); if (r < 0) - goto out; + return r; } - r = arp_network_bind_raw_socket(ll->index, ll->address, &ll->mac_addr); + r = sd_ipv4acd_start(ll->acd); if (r < 0) - goto out; + return r; - safe_close(ll->fd); - ll->fd = r; + return 0; +} - ipv4ll_set_state(ll, IPV4LL_STATE_INIT, true); +static void ipv4ll_client_notify(sd_ipv4ll *ll, int event) { + assert(ll); - r = sd_event_add_io(ll->event, &ll->receive_message, ll->fd, - EPOLLIN, ipv4ll_on_packet, ll); - if (r < 0) - goto out; + if (ll->cb) + ll->cb(ll, event, ll->userdata); +} - r = sd_event_source_set_priority(ll->receive_message, ll->event_priority); - if (r < 0) - goto out; +void ipv4ll_on_acd(sd_ipv4acd *acd, int event, void *userdata) { + sd_ipv4ll *ll = userdata; + IPV4LL_DONT_DESTROY(ll); + int r; - r = sd_event_source_set_description(ll->receive_message, "ipv4ll-receive-message"); - if (r < 0) - goto out; + assert(acd); + assert(ll); - r = ipv4ll_set_next_wakeup(ll, 0, 0); - if (r < 0) - goto out; -out: - if (r < 0) - ipv4ll_stop(ll); + switch (event) { + case IPV4ACD_EVENT_STOP: + ipv4ll_client_notify(ll, IPV4LL_EVENT_STOP); - return 0; + ll->claimed_address = 0; + + break; + case IPV4ACD_EVENT_BIND: + ll->claimed_address = ll->address; + ipv4ll_client_notify(ll, IPV4LL_EVENT_BIND); + + break; + case 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, 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, IPV4LL_EVENT_STOP); } -- cgit v1.2.3-54-g00ecf