On Thursday, July 20, 2023 6:35:53 AM CEST Linus Lüssing wrote:
[...]
+/**
- batadv_mcast_forw_orig_to_neigh() - get next hop neighbor to an orig
address + * @bat_priv: the bat priv with all the soft interface information
- @orig_addr: the originator MAC address to search the best next hop
router for + *
- Return: A neighbor node which is the best router towards the given
originator + * address.
- */
+static struct batadv_neigh_node * +batadv_mcast_forw_orig_to_neigh(struct batadv_priv *bat_priv, u8 *orig_addr) +{
- struct batadv_neigh_node *neigh_node;
- struct batadv_orig_node *orig_node;
- orig_node = batadv_orig_hash_find(bat_priv, orig_addr);
- if (!orig_node)
return NULL;- neigh_node = batadv_find_router(bat_priv, orig_node, NULL);
- batadv_orig_node_put(orig_node);
- return neigh_node;
+}
I was wondering if this shouldn't be a generic function rather than a multicast-specific function. It doesn't do anything multicast specific. I couldn't find something similar in other code though.
+/**
- batadv_mcast_forw_scrub_dests() - scrub destinations in a tracker TVLV
- @bat_priv: the bat priv with all the soft interface information
- @comp_neigh: next hop neighbor to scrub+collect destinations for
- @dest: start MAC entry in original skb's tracker TVLV
- @next_dest: start MAC entry in to be sent skb's tracker TVLV
- @num_dests: number of remaining destination MAC entries to iterate over
- This sorts destination entries into either the original batman-adv
- multicast packet or the skb (copy) that is going to be sent to
comp_neigh + * next.
- In preparation for the next, to be (unicast) transmitted batman-adv
multicast + * packet skb to be sent to the given neighbor node, tries to collect all + * originator MAC addresses that have the given neighbor node as their next hop + * in the to be transmitted skb (copy), which next_dest points into. That is we + * zero all destination entries in next_dest which do not have comp_neigh as + * their next hop. And zero all destination entries in the original skb that + * would have comp_neigh as their next hop (to avoid redundant transmissions and + * duplicated payload later).
- */
+static void +batadv_mcast_forw_scrub_dests(struct batadv_priv *bat_priv,
struct batadv_neigh_node *comp_neigh, u8 *dest,u8 *next_dest, u16 num_dests)+{
- struct batadv_neigh_node *next_neigh;
- /* skip first entry, this is what we are comparing with */
- eth_zero_addr(dest);
- dest += ETH_ALEN;
- next_dest += ETH_ALEN;
- num_dests--;
- batadv_mcast_forw_tracker_for_each_dest(next_dest, num_dests) {
if (is_zero_ether_addr(next_dest))goto scrub_next;if (is_multicast_ether_addr(next_dest)) {eth_zero_addr(dest);eth_zero_addr(next_dest);goto scrub_next;}next_neigh = batadv_mcast_forw_orig_to_neigh(bat_priv,next_dest);if (!next_neigh) {eth_zero_addr(next_dest);goto scrub_next;}/* Is this for our next packet to transmit? */if (batadv_compare_eth(next_neigh->addr, comp_neigh->addr))eth_zero_addr(dest);elseeth_zero_addr(next_dest);batadv_neigh_node_put(next_neigh);+scrub_next:
dest += ETH_ALEN;
I've read through that multiple times now, and I don't understand why next_dest isn't getting incremented within each iteration in the same way as dest. Is this a bug or am I missing something? Might be nicer to use one counter which is increased instead of two pointeres, e.g. &dest[counter] and &next_dest[counter] or similar to avoid those kind of bugs.
[...] +/**
- batadv_mcast_forw_tracker_tvlv_handler() - handle an mcast tracker tvlv
- @bat_priv: the bat priv with all the soft interface information
- @skb: the received batman-adv multicast packet
- Parses the tracker TVLV of an incoming batman-adv multicast packet and
- forwards the packet as indicated in this TVLV.
- Caller needs to set the skb network header to the start of the multicast
- tracker TVLV (excluding the generic TVLV header) and the skb transport
header + * to the next byte after this multicast tracker TVLV.
- Caller needs to free the skb.
- Return: NET_RX_SUCCESS or NET_RX_DROP on success or a negative error
- code on failure. NET_RX_SUCCESS if the received packet is supposed to be
- decapsulated and forwarded to the own soft interface, NET_RX_DROP
otherwise. + */ +int batadv_mcast_forw_tracker_tvlv_handler(struct batadv_priv *bat_priv,
struct sk_buff *skb)+{
- return batadv_mcast_forw_packet(bat_priv, skb, false);
+} diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 34903df4fe93..e46ce83c516a 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -942,6 +942,7 @@ struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv, #ifdef CONFIG_BATMAN_ADV_MCAST orig_node->mcast_flags = BATADV_MCAST_WANT_NO_RTR4; orig_node->mcast_flags |= BATADV_MCAST_WANT_NO_RTR6;
- orig_node->mcast_flags |= BATADV_MCAST_HAVE_MC_PTYPE_CAPA; INIT_HLIST_NODE(&orig_node->mcast_want_all_unsnoopables_node); INIT_HLIST_NODE(&orig_node->mcast_want_all_ipv4_node); INIT_HLIST_NODE(&orig_node->mcast_want_all_ipv6_node);
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 163cd43c4821..f1061985149f 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -1270,3 +1270,73 @@ int batadv_recv_bcast_packet(struct sk_buff *skb, batadv_orig_node_put(orig_node); return ret; }
+#ifdef CONFIG_BATMAN_ADV_MCAST +/**
- batadv_recv_mcast_packet() - process received batman-adv multicast
packet + * @skb: the received batman-adv multicast packet
- @recv_if: interface that the skb is received on
- Parses the given, received batman-adv multicast packet. Depending on the
- contents of its TVLV forwards it and/or decapsulates it to hand it to
the + * soft interface.
- Return: NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS
otherwise. + */ +int batadv_recv_mcast_packet(struct sk_buff *skb,
struct batadv_hard_iface *recv_if)+{
- struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface);
- struct batadv_mcast_packet *mcast_packet;
- int hdr_size = sizeof(*mcast_packet);
- unsigned char *tvlv_buff;
- int ret = NET_RX_DROP;
- u16 tvlv_buff_len;
- if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0)
goto free_skb;- /* create a copy of the skb, if needed, to modify it. */
- if (skb_cow(skb, ETH_HLEN) < 0)
goto free_skb;- /* packet needs to be linearized to access the tvlv content */
- if (skb_linearize(skb) < 0)
goto free_skb;- mcast_packet = (struct batadv_mcast_packet *)skb->data;
- if (mcast_packet->ttl-- < 2)
goto free_skb;
More of a nit (since we do the same check in broadcasts), but if ttl == 0 on the incoming packet, then we will actually forward it with ttl =255 and that's a bit stupid ...
Cheers, Simon