From 9d96e6c3efbe5ef52b2855612d51db52c469beb2 Mon Sep 17 00:00:00 2001 From: Tom Gundersen Date: Mon, 19 Oct 2015 22:15:50 +0200 Subject: sd-ndisc: introduce separate callbacks As the data passed is very different, we introduce four different callbacks: - Generic - router discovery timed out or state machine stopped - Router - router and link configuration received - Prefix onlink - configuration for an onlink prefix received - Prefix autonomous - configuration for to configure a SLAAC address for a prefix received --- src/libsystemd-network/sd-ndisc.c | 117 ++++++++++++++++++++++----------- src/libsystemd-network/test-ndisc-rs.c | 27 ++++---- 2 files changed, 91 insertions(+), 53 deletions(-) (limited to 'src/libsystemd-network') diff --git a/src/libsystemd-network/sd-ndisc.c b/src/libsystemd-network/sd-ndisc.c index b8bfc6c549..de3f26211e 100644 --- a/src/libsystemd-network/sd-ndisc.c +++ b/src/libsystemd-network/sd-ndisc.c @@ -29,6 +29,7 @@ #include "alloc-util.h" #include "async.h" #include "icmp6-util.h" +#include "in-addr-util.h" #include "list.h" #include "socket-util.h" @@ -47,6 +48,12 @@ enum NDiscState { #define ICMP6_RECV_SIZE (IP6_MIN_MTU - sizeof(struct ip6_hdr)) #define NDISC_OPT_LEN_UNITS 8 +#define ND_RA_FLAG_PREF 0x18 +#define ND_RA_FLAG_PREF_LOW 0x03 +#define ND_RA_FLAG_PREF_MEDIUM 0x0 +#define ND_RA_FLAG_PREF_HIGH 0x1 +#define ND_RA_FLAG_PREF_INVALID 0x2 + typedef struct NDiscPrefix NDiscPrefix; struct NDiscPrefix { @@ -75,6 +82,9 @@ struct sd_ndisc { sd_event_source *recv; sd_event_source *timeout; int nd_sent; + sd_ndisc_router_callback_t router_callback; + sd_ndisc_prefix_autonomous_callback_t prefix_autonomous_callback; + sd_ndisc_prefix_onlink_callback_t prefix_onlink_callback; sd_ndisc_callback_t callback; void *userdata; }; @@ -119,15 +129,17 @@ static int ndisc_prefix_new(sd_ndisc *nd, NDiscPrefix **ret) { return 0; } -static void ndisc_notify(sd_ndisc *nd, int event) { - if (nd->callback) - nd->callback(nd, event, nd->userdata); -} - -int sd_ndisc_set_callback(sd_ndisc *nd, sd_ndisc_callback_t callback, - void *userdata) { +int sd_ndisc_set_callback(sd_ndisc *nd, + sd_ndisc_router_callback_t router_callback, + sd_ndisc_prefix_onlink_callback_t prefix_onlink_callback, + sd_ndisc_prefix_autonomous_callback_t prefix_autonomous_callback, + sd_ndisc_callback_t callback, + void *userdata) { assert(nd); + nd->router_callback = router_callback; + nd->prefix_onlink_callback = prefix_onlink_callback; + nd->prefix_autonomous_callback = prefix_autonomous_callback; nd->callback = callback; nd->userdata = userdata; @@ -320,7 +332,7 @@ static int ndisc_prefix_match(sd_ndisc *nd, const struct in6_addr *addr, static int ndisc_prefix_update(sd_ndisc *nd, ssize_t len, const struct nd_opt_prefix_info *prefix_opt) { NDiscPrefix *prefix; - uint32_t lifetime; + uint32_t lifetime_valid, lifetime_preferred; usec_t time_now; char time_string[FORMAT_TIMESPAN_MAX]; int r; @@ -331,10 +343,17 @@ static int ndisc_prefix_update(sd_ndisc *nd, ssize_t len, if (len < prefix_opt->nd_opt_pi_len) return -ENOMSG; - if (!(prefix_opt->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK)) + if (!(prefix_opt->nd_opt_pi_flags_reserved & (ND_OPT_PI_FLAG_ONLINK | ND_OPT_PI_FLAG_AUTO))) + return 0; + + if (in_addr_is_link_local(AF_INET6, (const union in_addr_union *) &prefix_opt->nd_opt_pi_prefix) > 0) return 0; - lifetime = be32toh(prefix_opt->nd_opt_pi_valid_time); + lifetime_valid = be32toh(prefix_opt->nd_opt_pi_valid_time); + lifetime_preferred = be32toh(prefix_opt->nd_opt_pi_preferred_time); + + if (lifetime_valid < lifetime_preferred) + return 0; r = ndisc_prefix_match(nd, &prefix_opt->nd_opt_pi_prefix, prefix_opt->nd_opt_pi_prefix_len, &prefix); @@ -357,8 +376,8 @@ static int ndisc_prefix_update(sd_ndisc *nd, ssize_t len, log_ndisc(nd, "New prefix "SD_NDISC_ADDRESS_FORMAT_STR"/%d lifetime %d expires in %s", SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr), - prefix->len, lifetime, - format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime * USEC_PER_SEC, USEC_PER_SEC)); + prefix->len, lifetime_valid, + format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime_valid * USEC_PER_SEC, USEC_PER_SEC)); LIST_PREPEND(prefixes, nd->prefixes, prefix); @@ -378,17 +397,24 @@ static int ndisc_prefix_update(sd_ndisc *nd, ssize_t len, log_ndisc(nd, "Update prefix "SD_NDISC_ADDRESS_FORMAT_STR"/%d lifetime %d expires in %s", SD_NDISC_ADDRESS_FORMAT_VAL(prefix->addr), - prefix->len, lifetime, - format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime * USEC_PER_SEC, USEC_PER_SEC)); + prefix->len, lifetime_valid, + format_timespan(time_string, FORMAT_TIMESPAN_MAX, lifetime_valid * USEC_PER_SEC, USEC_PER_SEC)); } r = sd_event_now(nd->event, clock_boottime_or_monotonic(), &time_now); if (r < 0) return r; - prefix->valid_until = time_now + lifetime * USEC_PER_SEC; + prefix->valid_until = time_now + lifetime_valid * USEC_PER_SEC; - return r; + if ((prefix_opt->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_ONLINK) && nd->prefix_onlink_callback) + nd->prefix_onlink_callback(nd, &prefix->addr, prefix->len, prefix->valid_until, nd->userdata); + + if ((prefix_opt->nd_opt_pi_flags_reserved & ND_OPT_PI_FLAG_AUTO) && nd->prefix_autonomous_callback) + nd->prefix_autonomous_callback(nd, &prefix->addr, prefix->len, lifetime_preferred, lifetime_valid, + nd->userdata); + + return 0; } static int ndisc_ra_parse(sd_ndisc *nd, struct nd_router_advert *ra, @@ -453,11 +479,13 @@ static int ndisc_ra_parse(sd_ndisc *nd, struct nd_router_advert *ra, } static int ndisc_router_advertisment_recv(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + _cleanup_free_ struct nd_router_advert *ra = NULL; sd_ndisc *nd = userdata; - int r, buflen = 0; + int r, buflen = 0, pref, stateful; + union sockaddr_union router = {}; + socklen_t router_len = sizeof(router); + unsigned lifetime; ssize_t len; - _cleanup_free_ struct nd_router_advert *ra = NULL; - int event = SD_NDISC_EVENT_ROUTER_ADVERTISMENT_NONE; assert(s); assert(nd); @@ -471,9 +499,12 @@ static int ndisc_router_advertisment_recv(sd_event_source *s, int fd, uint32_t r if (!ra) return -ENOMEM; - len = read(fd, ra, buflen); + len = recvfrom(fd, ra, buflen, 0, &router.sa, &router_len); if (len < 0) { - log_ndisc(nd, "Could not receive message from UDP socket: %m"); + log_ndisc(nd, "Could not receive message from ICMPv6 socket: %m"); + return 0; + } else if (router_len != sizeof(router.in6) && router_len != 0) { + log_ndisc(nd, "Received invalid source address size from ICMPv6 socket: %zu bytes", (size_t)router_len); return 0; } @@ -487,26 +518,34 @@ static int ndisc_router_advertisment_recv(sd_event_source *s, int fd, uint32_t r nd->state = NDISC_STATE_ADVERTISMENT_LISTEN; - if (ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER ) - event = SD_NDISC_EVENT_ROUTER_ADVERTISMENT_OTHER; + stateful = ra->nd_ra_flags_reserved & (ND_RA_FLAG_MANAGED | ND_RA_FLAG_OTHER); + switch (ra->nd_ra_flags_reserved & ND_RA_FLAG_PREF >> 3) { + case ND_RA_FLAG_PREF_LOW: + pref = -1; + break; + case ND_RA_FLAG_PREF_HIGH: + pref = 1; + break; + default: + pref = 0; + break; + } - if (ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED) - event = SD_NDISC_EVENT_ROUTER_ADVERTISMENT_MANAGED; + lifetime = be16toh(ra->nd_ra_router_lifetime); - log_ndisc(nd, "Received Router Advertisement flags %s/%s", - ra->nd_ra_flags_reserved & ND_RA_FLAG_MANAGED ? "MANAGED" : "none", - ra->nd_ra_flags_reserved & ND_RA_FLAG_OTHER ? "OTHER" : "none"); + log_ndisc(nd, "Received Router Advertisement: flags %s preference %s lifetime %u sec", + stateful & ND_RA_FLAG_MANAGED ? "MANAGED" : stateful & ND_RA_FLAG_OTHER ? "OTHER" : "none", + pref == 1 ? "high" : pref == -1 ? "low" : "medium", + lifetime); - if (event != SD_NDISC_EVENT_ROUTER_ADVERTISMENT_NONE) { - r = ndisc_ra_parse(nd, ra, len); - if (r < 0) { - log_ndisc(nd, "Could not parse Router Advertisement: %s", - strerror(-r)); - return 0; - } + r = ndisc_ra_parse(nd, ra, len); + if (r < 0) { + log_ndisc(nd, "Could not parse Router Advertisement: %s", strerror(-r)); + return 0; } - ndisc_notify(nd, event); + if (nd->router_callback) + nd->router_callback(nd, stateful, router_len != 0 ? &router.in6.sin6_addr : NULL, lifetime, pref, nd->userdata); return 0; } @@ -525,7 +564,8 @@ static int ndisc_router_solicitation_timeout(sd_event_source *s, uint64_t usec, nd->timeout = sd_event_source_unref(nd->timeout); if (nd->nd_sent >= NDISC_MAX_ROUTER_SOLICITATIONS) { - ndisc_notify(nd, SD_NDISC_EVENT_ROUTER_ADVERTISMENT_TIMEOUT); + if (nd->callback) + nd->callback(nd, SD_NDISC_EVENT_TIMEOUT, nd->userdata); nd->state = NDISC_STATE_ADVERTISMENT_LISTEN; } else { if (memcmp(&nd->mac_addr, &unset, sizeof(struct ether_addr))) @@ -576,7 +616,8 @@ int sd_ndisc_stop(sd_ndisc *nd) { nd->state = NDISC_STATE_IDLE; - ndisc_notify(nd, SD_NDISC_EVENT_STOP); + if (nd->callback) + nd->callback(nd, SD_NDISC_EVENT_STOP, nd->userdata); return 0; } diff --git a/src/libsystemd-network/test-ndisc-rs.c b/src/libsystemd-network/test-ndisc-rs.c index 59c720d48d..a485be704e 100644 --- a/src/libsystemd-network/test-ndisc-rs.c +++ b/src/libsystemd-network/test-ndisc-rs.c @@ -85,31 +85,28 @@ int icmp6_send_router_solicitation(int s, const struct ether_addr *ether_addr) { return send_ra_function(0); } -static void test_rs_done(sd_ndisc *nd, int event, void *userdata) { +static void test_rs_done(sd_ndisc *nd, uint8_t flags, const struct in6_addr *gateway, unsigned lifetime, int pref, void *userdata) { sd_event *e = userdata; static unsigned idx = 0; - struct { - uint8_t flag; - int event; - } flag_event[] = { - { 0, SD_NDISC_EVENT_STOP }, - { 0, SD_NDISC_EVENT_STOP }, - { 0, SD_NDISC_EVENT_ROUTER_ADVERTISMENT_NONE }, - { ND_RA_FLAG_OTHER, SD_NDISC_EVENT_ROUTER_ADVERTISMENT_OTHER }, - { ND_RA_FLAG_MANAGED, SD_NDISC_EVENT_ROUTER_ADVERTISMENT_MANAGED } + uint8_t flags_array[] = { + 0, + 0, + 0, + ND_RA_FLAG_OTHER, + ND_RA_FLAG_MANAGED }; uint32_t mtu; assert_se(nd); - assert_se(event == flag_event[idx].event); + assert_se(flags == flags_array[idx]); idx++; if (verbose) - printf(" got event %d\n", event); + printf(" got event 0x%02x\n", flags); - if (idx < ELEMENTSOF(flag_event)) { - send_ra(flag_event[idx].flag); + if (idx < ELEMENTSOF(flags_array)) { + send_ra(flags_array[idx]); return; } @@ -137,7 +134,7 @@ static void test_rs(void) { assert_se(sd_ndisc_set_index(nd, 42) >= 0); assert_se(sd_ndisc_set_mac(nd, &mac_addr) >= 0); - assert_se(sd_ndisc_set_callback(nd, test_rs_done, e) >= 0); + assert_se(sd_ndisc_set_callback(nd, test_rs_done, NULL, NULL, NULL, e) >= 0); assert_se(sd_event_add_time(e, &test_hangcheck, clock_boottime_or_monotonic(), time_now + 2 *USEC_PER_SEC, 0, -- cgit v1.2.3-54-g00ecf