package/kernel/mac80211/patches/319-cfg80211-add-function-for-802.3-conversion-with-sepa.patch

   1 From: Felix Fietkau <nbd@openwrt.org>
   2 Date: Tue, 2 Feb 2016 14:39:09 +0100
   3 Subject: [PATCH] cfg80211: add function for 802.3 conversion with separate
   4  output buffer
   5
   6 Use skb_copy_bits in preparation for allowing fragmented skbs
   7
   8 Signed-off-by: Felix Fietkau <nbd@openwrt.org>
   9 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  10 ---
  11
  12 --- a/net/wireless/util.c
  13 +++ b/net/wireless/util.c
  14 @@ -393,9 +393,9 @@ unsigned int ieee80211_get_hdrlen_from_s
  15  }
  16  EXPORT_SYMBOL(ieee80211_get_hdrlen_from_skb);
  17
  18 -unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
  19 +static unsigned int __ieee80211_get_mesh_hdrlen(u8 flags)
  20  {
  21 -       int ae = meshhdr->flags & MESH_FLAGS_AE;
  22 +       int ae = flags & MESH_FLAGS_AE;
  23         /* 802.11-2012, 8.2.4.7.3 */
  24         switch (ae) {
  25         default:
  26 @@ -407,21 +407,31 @@ unsigned int ieee80211_get_mesh_hdrlen(s
  27                 return 18;
  28         }
  29  }
  30 +
  31 +unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr)
  32 +{
  33 +       return __ieee80211_get_mesh_hdrlen(meshhdr->flags);
  34 +}
  35  EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen);
  36
  37 -int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
  38 -                          enum nl80211_iftype iftype)
  39 +static int __ieee80211_data_to_8023(struct sk_buff *skb, struct ethhdr *ehdr,
  40 +                                   const u8 *addr, enum nl80211_iftype iftype)
  41  {
  42         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  43 -       u16 hdrlen, ethertype;
  44 -       u8 *payload;
  45 -       u8 dst[ETH_ALEN];
  46 -       u8 src[ETH_ALEN] __aligned(2);
  47 +       struct {
  48 +               u8 hdr[ETH_ALEN] __aligned(2);
  49 +               __be16 proto;
  50 +       } payload;
  51 +       struct ethhdr tmp;
  52 +       u16 hdrlen;
  53 +       u8 mesh_flags = 0;
  54
  55         if (unlikely(!ieee80211_is_data_present(hdr->frame_control)))
  56                 return -1;
  57
  58         hdrlen = ieee80211_hdrlen(hdr->frame_control);
  59 +       if (skb->len < hdrlen + 8)
  60 +               return -1;
  61
  62         /* convert IEEE 802.11 header + possible LLC headers into Ethernet
  63          * header
  64 @@ -432,8 +442,11 @@ int ieee80211_data_to_8023(struct sk_buf
  65          *   1     0   BSSID SA    DA    n/a
  66          *   1     1   RA    TA    DA    SA
  67          */
  68 -       memcpy(dst, ieee80211_get_DA(hdr), ETH_ALEN);
  69 -       memcpy(src, ieee80211_get_SA(hdr), ETH_ALEN);
  70 +       memcpy(tmp.h_dest, ieee80211_get_DA(hdr), ETH_ALEN);
  71 +       memcpy(tmp.h_source, ieee80211_get_SA(hdr), ETH_ALEN);
  72 +
  73 +       if (iftype == NL80211_IFTYPE_MESH_POINT)
  74 +               skb_copy_bits(skb, hdrlen, &mesh_flags, 1);
  75
  76         switch (hdr->frame_control &
  77                 cpu_to_le16(IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
  78 @@ -450,44 +463,31 @@ int ieee80211_data_to_8023(struct sk_buf
  79                              iftype != NL80211_IFTYPE_STATION))
  80                         return -1;
  81                 if (iftype == NL80211_IFTYPE_MESH_POINT) {
  82 -                       struct ieee80211s_hdr *meshdr =
  83 -                               (struct ieee80211s_hdr *) (skb->data + hdrlen);
  84 -                       /* make sure meshdr->flags is on the linear part */
  85 -                       if (!pskb_may_pull(skb, hdrlen + 1))
  86 -                               return -1;
  87 -                       if (meshdr->flags & MESH_FLAGS_AE_A4)
  88 +                       if (mesh_flags & MESH_FLAGS_AE_A4)
  89                                 return -1;
  90 -                       if (meshdr->flags & MESH_FLAGS_AE_A5_A6) {
  91 +                       if (mesh_flags & MESH_FLAGS_AE_A5_A6) {
  92                                 skb_copy_bits(skb, hdrlen +
  93                                         offsetof(struct ieee80211s_hdr, eaddr1),
  94 -                                       dst, ETH_ALEN);
  95 -                               skb_copy_bits(skb, hdrlen +
  96 -                                       offsetof(struct ieee80211s_hdr, eaddr2),
  97 -                                       src, ETH_ALEN);
  98 +                                       tmp.h_dest, 2 * ETH_ALEN);
  99                         }
 100 -                       hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
 101 +                       hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags);
 102                 }
 103                 break;
 104         case cpu_to_le16(IEEE80211_FCTL_FROMDS):
 105                 if ((iftype != NL80211_IFTYPE_STATION &&
 106                      iftype != NL80211_IFTYPE_P2P_CLIENT &&
 107                      iftype != NL80211_IFTYPE_MESH_POINT) ||
 108 -                   (is_multicast_ether_addr(dst) &&
 109 -                    ether_addr_equal(src, addr)))
 110 +                   (is_multicast_ether_addr(tmp.h_dest) &&
 111 +                    ether_addr_equal(tmp.h_source, addr)))
 112                         return -1;
 113                 if (iftype == NL80211_IFTYPE_MESH_POINT) {
 114 -                       struct ieee80211s_hdr *meshdr =
 115 -                               (struct ieee80211s_hdr *) (skb->data + hdrlen);
 116 -                       /* make sure meshdr->flags is on the linear part */
 117 -                       if (!pskb_may_pull(skb, hdrlen + 1))
 118 -                               return -1;
 119 -                       if (meshdr->flags & MESH_FLAGS_AE_A5_A6)
 120 +                       if (mesh_flags & MESH_FLAGS_AE_A5_A6)
 121                                 return -1;
 122 -                       if (meshdr->flags & MESH_FLAGS_AE_A4)
 123 +                       if (mesh_flags & MESH_FLAGS_AE_A4)
 124                                 skb_copy_bits(skb, hdrlen +
 125                                         offsetof(struct ieee80211s_hdr, eaddr1),
 126 -                                       src, ETH_ALEN);
 127 -                       hdrlen += ieee80211_get_mesh_hdrlen(meshdr);
 128 +                                       tmp.h_source, ETH_ALEN);
 129 +                       hdrlen += __ieee80211_get_mesh_hdrlen(mesh_flags);
 130                 }
 131                 break;
 132         case cpu_to_le16(0):
 133 @@ -498,33 +498,33 @@ int ieee80211_data_to_8023(struct sk_buf
 134                 break;
 135         }
 136
 137 -       if (!pskb_may_pull(skb, hdrlen + 8))
 138 -               return -1;
 139 -
 140 -       payload = skb->data + hdrlen;
 141 -       ethertype = (payload[6] << 8) | payload[7];
 142 +       skb_copy_bits(skb, hdrlen, &payload, sizeof(payload));
 143 +       tmp.h_proto = payload.proto;
 144
 145 -       if (likely((ether_addr_equal(payload, rfc1042_header) &&
 146 -                   ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
 147 -                  ether_addr_equal(payload, bridge_tunnel_header))) {
 148 +       if (likely((ether_addr_equal(payload.hdr, rfc1042_header) &&
 149 +                   tmp.h_proto != htons(ETH_P_AARP) &&
 150 +                   tmp.h_proto != htons(ETH_P_IPX)) ||
 151 +                  ether_addr_equal(payload.hdr, bridge_tunnel_header)))
 152                 /* remove RFC1042 or Bridge-Tunnel encapsulation and
 153                  * replace EtherType */
 154 -               skb_pull(skb, hdrlen + 6);
 155 -               memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
 156 -               memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
 157 -       } else {
 158 -               struct ethhdr *ehdr;
 159 -               __be16 len;
 160 +               hdrlen += ETH_ALEN + 2;
 161 +       else
 162 +               tmp.h_proto = htons(skb->len);
 163
 164 -               skb_pull(skb, hdrlen);
 165 -               len = htons(skb->len);
 166 +       pskb_pull(skb, hdrlen);
 167 +
 168 +       if (!ehdr)
 169                 ehdr = (struct ethhdr *) skb_push(skb, sizeof(struct ethhdr));
 170 -               memcpy(ehdr->h_dest, dst, ETH_ALEN);
 171 -               memcpy(ehdr->h_source, src, ETH_ALEN);
 172 -               ehdr->h_proto = len;
 173 -       }
 174 +       memcpy(ehdr, &tmp, sizeof(tmp));
 175 +
 176         return 0;
 177  }
 178 +
 179 +int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
 180 +                          enum nl80211_iftype iftype)
 181 +{
 182 +       return __ieee80211_data_to_8023(skb, NULL, addr, iftype);
 183 +}
 184  EXPORT_SYMBOL(ieee80211_data_to_8023);
 185
 186  int ieee80211_data_from_8023(struct sk_buff *skb, const u8 *addr,