batman-adv: set skb priority according to content

The skb priority field may help the wireless driver to choose the right
queue (e.g. WMM queues). This should be set in batman-adv, as this
information is only available here.

This patch adds support for IPv4/IPv6 DS fields and VLAN PCP. Note that
only VLAN PCP is used if a VLAN header is present. Also initially set
TC_PRIO_CONTROL only for self-generated packets, and keep the priority
set by higher layers.

Signed-off-by: Simon Wunderlich <simon@open-mesh.com>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>

10 files changed, 91 insertions, 2 deletions

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 62da5278014a..9886a2f804fc 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -478,6 +478,7 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
                 kfree(forw_packet_aggr);
                 goto out;
         }
+        forw_packet_aggr->skb->priority = TC_PRIO_CONTROL;
         skb_reserve(forw_packet_aggr->skb, ETH_HLEN);
 
         skb_buff = skb_put(forw_packet_aggr->skb, packet_len);
diff --git a/net/batman-adv/icmp_socket.c b/net/batman-adv/icmp_socket.c
index b27508b8085c..5a99bb4b6b82 100644
--- a/net/batman-adv/icmp_socket.c
+++ b/net/batman-adv/icmp_socket.c
@@ -183,6 +183,7 @@ static ssize_t batadv_socket_write(struct file *file, const char __user *buff,
                 goto out;
         }
 
+        skb->priority = TC_PRIO_CONTROL;
         skb_reserve(skb, ETH_HLEN);
         icmp_packet = (struct batadv_icmp_packet_rr *)skb_put(skb, packet_len);
 
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 08125f3f6064..c72d1bcdcf49 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -19,6 +19,10 @@
 
 #include <linux/crc32c.h>
 #include <linux/highmem.h>
+#include <linux/if_vlan.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/dsfield.h>
 #include "main.h"
 #include "sysfs.h"
 #include "debugfs.h"
@@ -249,6 +253,60 @@ out:
         return primary_if;
 }
 
+/**
+ * batadv_skb_set_priority - sets skb priority according to packet content
+ * @skb: the packet to be sent
+ * @offset: offset to the packet content
+ *
+ * This function sets a value between 256 and 263 (802.1d priority), which
+ * can be interpreted by the cfg80211 or other drivers.
+ */
+void batadv_skb_set_priority(struct sk_buff *skb, int offset)
+{
+        struct iphdr ip_hdr_tmp, *ip_hdr;
+        struct ipv6hdr ip6_hdr_tmp, *ip6_hdr;
+        struct ethhdr ethhdr_tmp, *ethhdr;
+        struct vlan_ethhdr *vhdr, vhdr_tmp;
+        u32 prio;
+
+        /* already set, do nothing */
+        if (skb->priority >= 256 && skb->priority <= 263)
+                return;
+
+        ethhdr = skb_header_pointer(skb, offset, sizeof(*ethhdr), &ethhdr_tmp);
+        if (!ethhdr)
+                return;
+
+        switch (ethhdr->h_proto) {
+        case htons(ETH_P_8021Q):
+                vhdr = skb_header_pointer(skb, offset + sizeof(*vhdr),
+                                          sizeof(*vhdr), &vhdr_tmp);
+                if (!vhdr)
+                        return;
+                prio = ntohs(vhdr->h_vlan_TCI) & VLAN_PRIO_MASK;
+                prio = prio >> VLAN_PRIO_SHIFT;
+                break;
+        case htons(ETH_P_IP):
+                ip_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
+                                            sizeof(*ip_hdr), &ip_hdr_tmp);
+                if (!ip_hdr)
+                        return;
+                prio = (ipv4_get_dsfield(ip_hdr) & 0xfc) >> 5;
+                break;
+        case htons(ETH_P_IPV6):
+                ip6_hdr = skb_header_pointer(skb, offset + sizeof(*ethhdr),
+                                             sizeof(*ip6_hdr), &ip6_hdr_tmp);
+                if (!ip6_hdr)
+                        return;
+                prio = (ipv6_get_dsfield(ip6_hdr) & 0xfc) >> 5;
+                break;
+        default:
+                return;
+        }
+
+        skb->priority = prio + 256;
+}
+
 static int batadv_recv_unhandled_packet(struct sk_buff *skb,
                                         struct batadv_hard_iface *recv_if)
 {
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index 5e9aebb7d56b..a7bca78a6251 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -184,6 +184,7 @@ void batadv_mesh_free(struct net_device *soft_iface);
 int batadv_is_my_mac(struct batadv_priv *bat_priv, const uint8_t *addr);
 struct batadv_hard_iface *
 batadv_seq_print_text_primary_if_get(struct seq_file *seq);
+void batadv_skb_set_priority(struct sk_buff *skb, int offset);
 int batadv_batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
                            struct packet_type *ptype,
                            struct net_device *orig_dev);
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 2f0bd3ffe6e8..0439395d7ba5 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -775,7 +775,7 @@ static int batadv_route_unicast_packet(struct sk_buff *skb,
         struct batadv_neigh_node *neigh_node = NULL;
         struct batadv_unicast_packet *unicast_packet;
         struct ethhdr *ethhdr = eth_hdr(skb);
-        int res, ret = NET_RX_DROP;
+        int res, hdr_len, ret = NET_RX_DROP;
         struct sk_buff *new_skb;
 
         unicast_packet = (struct batadv_unicast_packet *)skb->data;
@@ -835,6 +835,22 @@ static int batadv_route_unicast_packet(struct sk_buff *skb,
         /* decrement ttl */
         unicast_packet->header.ttl--;
 
+        switch (unicast_packet->header.packet_type) {
+        case BATADV_UNICAST_4ADDR:
+                hdr_len = sizeof(struct batadv_unicast_4addr_packet);
+                break;
+        case BATADV_UNICAST:
+                hdr_len = sizeof(struct batadv_unicast_packet);
+                break;
+        default:
+                /* other packet types not supported - yet */
+                hdr_len = -1;
+                break;
+        }
+
+        if (hdr_len > 0)
+                batadv_skb_set_priority(skb, hdr_len);
+
         res = batadv_send_skb_to_orig(skb, orig_node, recv_if);
 
         /* translate transmit result into receive result */
@@ -1193,6 +1209,8 @@ int batadv_recv_bcast_packet(struct sk_buff *skb,
         if (batadv_bla_check_bcast_duplist(bat_priv, skb))
                 goto out;
 
+        batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet));
+
         /* rebroadcast packet */
         batadv_add_bcast_packet_to_list(bat_priv, skb, 1);
 
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index e9ff8d801201..0266edd0fa7f 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -67,7 +67,6 @@ int batadv_send_skb_packet(struct sk_buff *skb,
         ethhdr->h_proto = __constant_htons(ETH_P_BATMAN);
 
         skb_set_network_header(skb, ETH_HLEN);
-        skb->priority = TC_PRIO_CONTROL;
         skb->protocol = __constant_htons(ETH_P_BATMAN);
 
         skb->dev = hard_iface->net_dev;
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index 0f04e1c302b4..4493913f0d5c 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c
@@ -229,6 +229,8 @@ static int batadv_interface_tx(struct sk_buff *skb,
                  */
         }
 
+        batadv_skb_set_priority(skb, 0);
+
         /* ethernet packet should be broadcasted */
         if (do_bcast) {
                 primary_if = batadv_primary_if_get_selected(bat_priv);
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 429aeef3d8b2..34510f38708f 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1626,6 +1626,7 @@ batadv_tt_response_fill_table(uint16_t tt_len, uint8_t ttvn,
         if (!skb)
                 goto out;
 
+        skb->priority = TC_PRIO_CONTROL;
         skb_reserve(skb, ETH_HLEN);
         tt_response = (struct batadv_tt_query_packet *)skb_put(skb, len);
         tt_response->ttvn = ttvn;
@@ -1691,6 +1692,7 @@ static int batadv_send_tt_request(struct batadv_priv *bat_priv,
         if (!skb)
                 goto out;
 
+        skb->priority = TC_PRIO_CONTROL;
         skb_reserve(skb, ETH_HLEN);
 
         tt_req_len = sizeof(*tt_request);
@@ -1788,6 +1790,7 @@ batadv_send_other_tt_response(struct batadv_priv *bat_priv,
                 if (!skb)
                         goto unlock;
 
+                skb->priority = TC_PRIO_CONTROL;
                 skb_reserve(skb, ETH_HLEN);
                 packet_pos = skb_put(skb, len);
                 tt_response = (struct batadv_tt_query_packet *)packet_pos;
@@ -1906,6 +1909,7 @@ batadv_send_my_tt_response(struct batadv_priv *bat_priv,
                 if (!skb)
                         goto unlock;
 
+                skb->priority = TC_PRIO_CONTROL;
                 skb_reserve(skb, ETH_HLEN);
                 packet_pos = skb_put(skb, len);
                 tt_response = (struct batadv_tt_query_packet *)packet_pos;
@@ -2240,6 +2244,7 @@ static void batadv_send_roam_adv(struct batadv_priv *bat_priv, uint8_t *client,
         if (!skb)
                 goto out;
 
+        skb->priority = TC_PRIO_CONTROL;
         skb_reserve(skb, ETH_HLEN);
 
         roam_adv_packet = (struct batadv_roam_adv_packet *)skb_put(skb, len);
diff --git a/net/batman-adv/unicast.c b/net/batman-adv/unicast.c
index 857e1b8349ee..48b31d33ce6b 100644
--- a/net/batman-adv/unicast.c
+++ b/net/batman-adv/unicast.c
@@ -242,6 +242,8 @@ int batadv_frag_send_skb(struct sk_buff *skb, struct batadv_priv *bat_priv,
         frag_skb = dev_alloc_skb(data_len - (data_len / 2) + ucf_hdr_len);
         if (!frag_skb)
                 goto dropped;
+
+        skb->priority = TC_PRIO_CONTROL;
         skb_reserve(frag_skb, ucf_hdr_len);
 
         unicast_packet = (struct batadv_unicast_packet *)skb->data;
diff --git a/net/batman-adv/vis.c b/net/batman-adv/vis.c
index 4983340f1943..d8ea31a58457 100644
--- a/net/batman-adv/vis.c
+++ b/net/batman-adv/vis.c
@@ -397,6 +397,7 @@ batadv_add_packet(struct batadv_priv *bat_priv,
                 kfree(info);
                 return NULL;
         }
+        info->skb_packet->priority = TC_PRIO_CONTROL;
         skb_reserve(info->skb_packet, ETH_HLEN);
         packet = (struct batadv_vis_packet *)skb_put(info->skb_packet, len);
 
@@ -861,6 +862,7 @@ int batadv_vis_init(struct batadv_priv *bat_priv)
         if (!bat_priv->vis.my_info->skb_packet)
                 goto free_info;
 
+        bat_priv->vis.my_info->skb_packet->priority = TC_PRIO_CONTROL;
         skb_reserve(bat_priv->vis.my_info->skb_packet, ETH_HLEN);
         tmp_skb = bat_priv->vis.my_info->skb_packet;
         packet = (struct batadv_vis_packet *)skb_put(tmp_skb, sizeof(*packet));