diff options
Diffstat (limited to 'src/tlv_types.c')
| -rw-r--r-- | src/tlv_types.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/src/tlv_types.c b/src/tlv_types.c new file mode 100644 index 0000000..a3f1fbb --- /dev/null +++ b/src/tlv_types.c @@ -0,0 +1,145 @@ +/* + Copyright (c) 2013, Matthias Schiffer <mschiffer@universe-factory.net> + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + 1. Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + 2. Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +*/ + + +#include "babel.h" +#include "neigh.h" +#include "packet.h" +#include "tlv_types.h" + +#include <stdlib.h> + + +typedef struct handle_tlv_arg { + gp_babel_iface_t *iface; + const gmrf_addr_t *source; + + gp_babel_node_id_t node_id; +} handle_tlv_arg_t; + +static inline gp_babel_neigh_t* get_tlv_neigh(handle_tlv_arg_t *arg) { + return gp_babel_neigh_get(arg->iface, arg->source); +} + +static void handle_tlv_hello(gmrf_t *gmrf, gmrf_context_t *ctx, const gp_babel_tlv_hello_t *tlv_hello, size_t len, handle_tlv_arg_t *arg) { + if (len < sizeof(gp_babel_tlv_hello_t)) { + gmrf_logf(gmrf, LOG_WARNING, "received short hello TLV."); + return; + } + + gmrf_logf(gmrf, LOG_DEBUG, "received hello with seqno %u.", ntohs(tlv_hello->seqno)); + + gp_babel_neigh_t *neigh = get_tlv_neigh(arg); + + uint16_t seqno = ntohs(tlv_hello->seqno); + + if (neigh->last_hello != gmrf_time_unspec) { + int timediff = (gmrf_now(gmrf) - neigh->last_hello)/10; + uint16_t seqexp = neigh->last_seqno + (timediff - neigh->hello_interval/2)/neigh->hello_interval; + + /* cast to int16_t to ensure correct handling of seqno wrapping */ + if (abs((int16_t)(seqno - seqexp)) > 16) { + gmrf_logf(gmrf, LOG_INFO, "neighbour was reset."); + neigh->hello_log = 0; + neigh->txcost = 0xffff; + } + else { + int16_t seqdiff = seqno - neigh->last_seqno; + if (seqdiff <= 0) { + gmrf_logf(gmrf, LOG_DEBUG, "seqno already seen, ignoring."); + return; + } + + neigh->hello_log <<= seqdiff; + } + } + else { + gmrf_logf(gmrf, LOG_DEBUG, "received hello from new neighbour."); + } + + neigh->hello_log |= 1; + neigh->hello_interval = ntohs(tlv_hello->interval); + neigh->last_seqno = seqno; + neigh->last_hello = gmrf_now(gmrf); + + if (neigh->hello_log == 1) /* new or reset neighbour */ + gp_babel_neigh_reset(arg->iface, neigh); + + gmrf_logf(gmrf, LOG_DEBUG, "accepted hello, log %04x, rxcost is %u, cost is %u now.", neigh->hello_log, gp_babel_neigh_get_rxcost(gmrf, neigh), gp_babel_neigh_get_cost(gmrf, neigh)); +} + +static void handle_tlv_ihu(gmrf_t *gmrf, gmrf_context_t *ctx, const gp_babel_tlv_ihu_t *tlv_ihu, size_t len, handle_tlv_arg_t *arg) { + if (len < sizeof(gp_babel_tlv_ihu_t)) { + gmrf_logf(gmrf, LOG_WARNING, "received short IHU TLV."); + return; + } + + if (tlv_ihu->ae == ADDR_ENC_GMRF) { + if (len < sizeof(gp_babel_tlv_ihu_t)+sizeof(gmrf_addr_t)) { + gmrf_logf(gmrf, LOG_WARNING, "received short IHU TLV."); + return; + } + + gmrf_addr_t iface_addr = gmrf_iface_get_addr(gmrf, arg->iface->gmrf_iface); + if (memcmp(tlv_ihu->address, &iface_addr, sizeof(gmrf_addr_t)) != 0) + return; + } + else if (tlv_ihu->ae != ADDR_ENC_UNSPEC) { + return; + } + + gp_babel_neigh_t *neigh = get_tlv_neigh(arg); + neigh->ihu_interval = ntohs(tlv_ihu->interval); + neigh->last_ihu = gmrf_now(gmrf); + neigh->txcost = ntohs(tlv_ihu->rxcost); + + gmrf_logf(gmrf, LOG_DEBUG, "accepted IHU, txcost is %u, cost is %u now.", gp_babel_neigh_get_txcost(gmrf, neigh), gp_babel_neigh_get_cost(gmrf, neigh)); +} + +static void handle_tlv(gmrf_t *gmrf, gmrf_context_t *ctx, gp_babel_tlv_type_t type, const void *data, size_t len, void *arg) { + handle_tlv_arg_t *tlv_arg = arg; + + switch (type) { + case TLV_HELLO: + handle_tlv_hello(gmrf, ctx, data, len, tlv_arg); + return; + + case TLV_IHU: + handle_tlv_ihu(gmrf, ctx, data, len, tlv_arg); + return; + + default: + gmrf_logf(gmrf, LOG_DEBUG, "received unknown TLV %u on %s.", type, gmrf_iface_get_name(gmrf, tlv_arg->iface->gmrf_iface)); + return; + } +} + +void gp_babel_handle_packet(gmrf_t *gmrf, gmrf_context_t *ctx, gp_babel_iface_t *iface, const gmrf_addr_t *source, const gp_babel_packet_t *packet) { + handle_tlv_arg_t arg = { .iface = iface, .source = source }; + + if (!gp_babel_tlv_parse(gmrf, ctx, packet, handle_tlv, &arg)) { + gmrf_logf(gmrf, LOG_DEBUG, "received invalid packet."); + } +} |