// SPDX-License-Identifier: GPL-2.0 /* Copyright (C) B.A.T.M.A.N. contributors: * * Linus Lüssing */ #include "multicast.h" #include "main.h" #include <linux/bug.h> #include <linux/build_bug.h> #include <linux/byteorder/generic.h> #include <linux/compiler.h> #include <linux/errno.h> #include <linux/etherdevice.h> #include <linux/gfp.h> #include <linux/if_ether.h> #include <linux/if_vlan.h> #include <linux/ipv6.h> #include <linux/limits.h> #include <linux/netdevice.h> #include <linux/rculist.h> #include <linux/rcupdate.h> #include <linux/skbuff.h> #include <linux/stddef.h> #include <linux/string.h> #include <linux/types.h> #include <uapi/linux/batadv_packet.h> #include "bridge_loop_avoidance.h" #include "originator.h" #include "send.h" #include "translation-table.h" #define batadv_mcast_forw_tracker_for_each_dest(dest, num_dests) … #define batadv_mcast_forw_tracker_for_each_dest2(dest1, dest2, num_dests) … /** * batadv_mcast_forw_skb_push() - skb_push and memorize amount of pushed bytes * @skb: the skb to push onto * @size: the amount of bytes to push * @len: stores the total amount of bytes pushed * * Performs an skb_push() onto the given skb and adds the amount of pushed bytes * to the given len pointer. * * Return: the return value of the skb_push() call. */ static void *batadv_mcast_forw_skb_push(struct sk_buff *skb, size_t size, unsigned short *len) { … } /** * batadv_mcast_forw_push_padding() - push 2 padding bytes to skb's front * @skb: the skb to push onto * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Pushes two padding bytes to the front of the given skb. * * Return: On success a pointer to the first byte of the two pushed padding * bytes within the skb. NULL otherwise. */ static char * batadv_mcast_forw_push_padding(struct sk_buff *skb, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_est_padding() - push padding bytes if necessary * @skb: the skb to potentially push the padding onto * @count: the (estimated) number of originators the multicast packet needs to * be sent to * @tvlv_len: stores the amount of currently pushed TVLV bytes * * If the number of destination entries is even then this adds two * padding bytes to the end of the tracker TVLV. * * Return: true on success or if no padding is needed, false otherwise. */ static bool batadv_mcast_forw_push_est_padding(struct sk_buff *skb, int count, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_orig_entry() - get orig_node from an hlist node * @node: the hlist node to get the orig_node from * @entry_offset: the offset of the hlist node within the orig_node struct * * Return: The orig_node containing the hlist node on success, NULL on error. */ static struct batadv_orig_node * batadv_mcast_forw_orig_entry(struct hlist_node *node, size_t entry_offset) { … } /** * batadv_mcast_forw_push_dest() - push an originator MAC address onto an skb * @bat_priv: the bat priv with all the soft interface information * @skb: the skb to push the destination address onto * @vid: the vlan identifier * @orig_node: the originator node to get the MAC address from * @num_dests: a pointer to store the number of pushed addresses in * @tvlv_len: stores the amount of currently pushed TVLV bytes * * If the orig_node is a BLA backbone gateway, if there is not enough skb * headroom available or if num_dests is already at its maximum (65535) then * neither the skb nor num_dests is changed. Otherwise the originator's MAC * address is pushed onto the given skb and num_dests incremented by one. * * Return: true if the orig_node is a backbone gateway or if an orig address * was pushed successfully, false otherwise. */ static bool batadv_mcast_forw_push_dest(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid, struct batadv_orig_node *orig_node, unsigned short *num_dests, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_dests_list() - push originators from list onto an skb * @bat_priv: the bat priv with all the soft interface information * @skb: the skb to push the destination addresses onto * @vid: the vlan identifier * @head: the list to gather originators from * @entry_offset: offset of an hlist node in an orig_node structure * @num_dests: a pointer to store the number of pushed addresses in * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Push the MAC addresses of all originators in the given list onto the given * skb. * * Return: true on success, false otherwise. */ static int batadv_mcast_forw_push_dests_list(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid, struct hlist_head *head, size_t entry_offset, unsigned short *num_dests, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_tt() - push originators with interest through TT * @bat_priv: the bat priv with all the soft interface information * @skb: the skb to push the destination addresses onto * @vid: the vlan identifier * @num_dests: a pointer to store the number of pushed addresses in * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Push the MAC addresses of all originators which have indicated interest in * this multicast packet through the translation table onto the given skb. * * Return: true on success, false otherwise. */ static bool batadv_mcast_forw_push_tt(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid, unsigned short *num_dests, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_want_all() - push originators with want-all flag * @bat_priv: the bat priv with all the soft interface information * @skb: the skb to push the destination addresses onto * @vid: the vlan identifier * @num_dests: a pointer to store the number of pushed addresses in * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Push the MAC addresses of all originators which have indicated interest in * this multicast packet through the want-all flag onto the given skb. * * Return: true on success, false otherwise. */ static bool batadv_mcast_forw_push_want_all(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid, unsigned short *num_dests, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_want_rtr() - push originators with want-router flag * @bat_priv: the bat priv with all the soft interface information * @skb: the skb to push the destination addresses onto * @vid: the vlan identifier * @num_dests: a pointer to store the number of pushed addresses in * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Push the MAC addresses of all originators which have indicated interest in * this multicast packet through the want-all-rtr flag onto the given skb. * * Return: true on success, false otherwise. */ static bool batadv_mcast_forw_push_want_rtr(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid, unsigned short *num_dests, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_scrape() - remove bytes within skb data * @skb: the skb to remove bytes from * @offset: the offset from the skb data from which to scrape * @len: the amount of bytes to scrape starting from the offset * * Scrapes/removes len bytes from the given skb at the given offset from the * skb data. * * Caller needs to ensure that the region from the skb data's start up * to/including the to be removed bytes are linearized. */ static void batadv_mcast_forw_scrape(struct sk_buff *skb, unsigned short offset, unsigned short len) { … } /** * batadv_mcast_forw_push_scrape_padding() - remove TVLV padding * @skb: the skb to potentially adjust the TVLV's padding on * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Remove two padding bytes from the end of the multicast tracker TVLV, * from before the payload data. * * Caller needs to ensure that the TVLV bytes are linearized. */ static void batadv_mcast_forw_push_scrape_padding(struct sk_buff *skb, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_insert_padding() - insert TVLV padding * @skb: the skb to potentially adjust the TVLV's padding on * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Inserts two padding bytes at the end of the multicast tracker TVLV, * before the payload data in the given skb. * * Return: true on success, false otherwise. */ static bool batadv_mcast_forw_push_insert_padding(struct sk_buff *skb, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_adjust_padding() - adjust padding if necessary * @skb: the skb to potentially adjust the TVLV's padding on * @count: the estimated number of originators the multicast packet needs to * be sent to * @num_dests_pushed: the number of originators that were actually added to the * multicast packet's tracker TVLV * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Adjusts the padding in the multicast packet's tracker TVLV depending on the * initially estimated amount of destinations versus the amount of destinations * that were actually added to the tracker TVLV. * * If the initial estimate was correct or at least the oddness was the same then * no padding adjustment is performed. * If the initially estimated number was even, so padding was initially added, * but it turned out to be odd then padding is removed. * If the initially estimated number was odd, so no padding was initially added, * but it turned out to be even then padding is added. * * Return: true if no padding adjustment is needed or the adjustment was * successful, false otherwise. */ static bool batadv_mcast_forw_push_adjust_padding(struct sk_buff *skb, int *count, unsigned short num_dests_pushed, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_dests() - push originator addresses onto an skb * @bat_priv: the bat priv with all the soft interface information * @skb: the skb to push the destination addresses onto * @vid: the vlan identifier * @is_routable: indicates whether the destination is routable * @count: the number of originators the multicast packet needs to be sent to * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Push the MAC addresses of all originators which have indicated interest in * this multicast packet onto the given skb. * * Return: -ENOMEM if there is not enough skb headroom available. Otherwise, on * success 0. */ static int batadv_mcast_forw_push_dests(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid, int is_routable, int *count, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_tracker() - push a multicast tracker TVLV header * @skb: the skb to push the tracker TVLV onto * @num_dests: the number of destination addresses to set in the header * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Pushes a multicast tracker TVLV header onto the given skb, including the * generic TVLV header but excluding the destination MAC addresses. * * The provided num_dests value is taken into consideration to set the * num_dests field in the tracker header and to set the appropriate TVLV length * value fields. * * Return: -ENOMEM if there is not enough skb headroom available. Otherwise, on * success 0. */ static int batadv_mcast_forw_push_tracker(struct sk_buff *skb, int num_dests, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_tvlvs() - push a multicast tracker TVLV onto an skb * @bat_priv: the bat priv with all the soft interface information * @skb: the skb to push the tracker TVLV onto * @vid: the vlan identifier * @is_routable: indicates whether the destination is routable * @count: the number of originators the multicast packet needs to be sent to * @tvlv_len: stores the amount of currently pushed TVLV bytes * * Pushes a multicast tracker TVLV onto the given skb, including the collected * destination MAC addresses and the generic TVLV header. * * Return: -ENOMEM if there is not enough skb headroom available. Otherwise, on * success 0. */ static int batadv_mcast_forw_push_tvlvs(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid, int is_routable, int count, unsigned short *tvlv_len) { … } /** * batadv_mcast_forw_push_hdr() - push a multicast packet header onto an skb * @skb: the skb to push the header onto * @tvlv_len: the total TVLV length value to set in the header * * Pushes a batman-adv multicast packet header onto the given skb and sets * the provided total TVLV length value in it. * * Caller needs to ensure enough skb headroom is available. * * Return: -ENOMEM if there is not enough skb headroom available. Otherwise, on * success 0. */ static int batadv_mcast_forw_push_hdr(struct sk_buff *skb, unsigned short tvlv_len) { … } /** * 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) { … } /** * batadv_mcast_forw_shrink_fill() - swap slot with next non-zero destination * @slot: the to be filled zero-MAC destination entry in a tracker TVLV * @num_dests_slot: remaining entries in tracker TVLV from/including slot * * Searches for the next non-zero-MAC destination entry in a tracker TVLV after * the given slot pointer. And if found, swaps it with the zero-MAC destination * entry which the slot points to. * * Return: true if slot was swapped/filled successfully, false otherwise. */ static bool batadv_mcast_forw_shrink_fill(u8 *slot, u16 num_dests_slot) { … } /** * batadv_mcast_forw_shrink_pack_dests() - pack destinations of a tracker TVLV * @skb: the batman-adv multicast packet to compact destinations in * * Compacts the originator destination MAC addresses in the multicast tracker * TVLV of the given multicast packet. This is done by moving all non-zero * MAC addresses in direction of the skb head and all zero MAC addresses in skb * tail direction, within the multicast tracker TVLV. * * Return: The number of consecutive zero MAC address destinations which are * now at the end of the multicast tracker TVLV. */ static int batadv_mcast_forw_shrink_pack_dests(struct sk_buff *skb) { … } /** * batadv_mcast_forw_shrink_align_offset() - get new alignment offset * @num_dests_old: the old, to be updated amount of destination nodes * @num_dests_reduce: the number of destinations that were removed * * Calculates the amount of potential extra alignment offset that is needed to * adjust the TVLV padding after the change in destination nodes. * * Return: * 0: If no change to padding is needed. * 2: If padding needs to be removed. * -2: If padding needs to be added. */ static short batadv_mcast_forw_shrink_align_offset(unsigned int num_dests_old, unsigned int num_dests_reduce) { … } /** * batadv_mcast_forw_shrink_update_headers() - update shrunk mc packet headers * @skb: the batman-adv multicast packet to update headers of * @num_dests_reduce: the number of destinations that were removed * * This updates any fields of a batman-adv multicast packet that are affected * by the reduced number of destinations in the multicast tracket TVLV. In * particular this updates: * * The num_dest field of the multicast tracker TVLV. * The TVLV length field of the according generic TVLV header. * The batman-adv multicast packet's total TVLV length field. * * Return: The offset in skb's tail direction at which the new batman-adv * multicast packet header needs to start. */ static unsigned int batadv_mcast_forw_shrink_update_headers(struct sk_buff *skb, unsigned int num_dests_reduce) { … } /** * batadv_mcast_forw_shrink_move_headers() - move multicast headers by offset * @skb: the batman-adv multicast packet to move headers for * @offset: a non-negative offset to move headers by, towards the skb tail * * Moves the batman-adv multicast packet header, its multicast tracker TVLV and * any TVLVs in between by the given offset in direction towards the tail. */ static void batadv_mcast_forw_shrink_move_headers(struct sk_buff *skb, unsigned int offset) { … } /** * batadv_mcast_forw_shrink_tracker() - remove zero addresses in a tracker tvlv * @skb: the batman-adv multicast packet to (potentially) shrink * * Removes all destinations with a zero MAC addresses (00:00:00:00:00:00) from * the given batman-adv multicast packet's tracker TVLV and updates headers * accordingly to maintain a valid batman-adv multicast packet. */ static void batadv_mcast_forw_shrink_tracker(struct sk_buff *skb) { … } /** * batadv_mcast_forw_packet() - forward a batman-adv multicast packet * @bat_priv: the bat priv with all the soft interface information * @skb: the received or locally generated batman-adv multicast packet * @local_xmit: indicates that the packet was locally generated and not received * * Parses the tracker TVLV of a 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. */ static int batadv_mcast_forw_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, bool local_xmit) { … } /** * 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) { … } /** * batadv_mcast_forw_packet_hdrlen() - multicast packet header length * @num_dests: number of destination nodes * * Calculates the total batman-adv multicast packet header length for a given * number of destination nodes (excluding the outer ethernet frame). * * Return: The calculated total batman-adv multicast packet header length. */ unsigned int batadv_mcast_forw_packet_hdrlen(unsigned int num_dests) { … } /** * batadv_mcast_forw_expand_head() - expand headroom for an mcast packet * @bat_priv: the bat priv with all the soft interface information * @skb: the multicast packet to send * * Tries to expand an skb's headroom so that its head to tail is 1298 * bytes (minimum IPv6 MTU + vlan ethernet header size) large. * * Return: -EINVAL if the given skb's length is too large or -ENOMEM on memory * allocation failure. Otherwise, on success, zero is returned. */ static int batadv_mcast_forw_expand_head(struct batadv_priv *bat_priv, struct sk_buff *skb) { … } /** * batadv_mcast_forw_push() - encapsulate skb in a batman-adv multicast packet * @bat_priv: the bat priv with all the soft interface information * @skb: the multicast packet to encapsulate and send * @vid: the vlan identifier * @is_routable: indicates whether the destination is routable * @count: the number of originators the multicast packet needs to be sent to * * Encapsulates the given multicast packet in a batman-adv multicast packet. * A multicast tracker TVLV with destination originator addresses for any node * that signaled interest in it, that is either via the translation table or the * according want-all flags, is attached accordingly. * * Return: true on success, false otherwise. */ bool batadv_mcast_forw_push(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid, int is_routable, int count) { … } /** * batadv_mcast_forw_mcsend() - send a self prepared batman-adv multicast packet * @bat_priv: the bat priv with all the soft interface information * @skb: the multicast packet to encapsulate and send * * Transmits a batman-adv multicast packet that was locally prepared and * consumes/frees it. * * Return: NET_XMIT_DROP on memory allocation failure. NET_XMIT_SUCCESS * otherwise. */ int batadv_mcast_forw_mcsend(struct batadv_priv *bat_priv, struct sk_buff *skb) { … }
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