diff options
| -rw-r--r-- | include/uapi/linux/if_packet.h | 1 | ||||
| -rw-r--r-- | net/packet/af_packet.c | 44 |
2 files changed, 45 insertions, 0 deletions
diff --git a/include/uapi/linux/if_packet.h b/include/uapi/linux/if_packet.h index 9e7edfd8141e..4df96a7dd4fa 100644 --- a/include/uapi/linux/if_packet.h +++ b/include/uapi/linux/if_packet.h @@ -66,6 +66,7 @@ struct sockaddr_ll { #define PACKET_FANOUT_CBPF 6 #define PACKET_FANOUT_EBPF 7 #define PACKET_FANOUT_FLAG_ROLLOVER 0x1000 +#define PACKET_FANOUT_FLAG_UNIQUEID 0x2000 #define PACKET_FANOUT_FLAG_DEFRAG 0x8000 struct tpacket_stats { diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 8489beff5c25..94052f42058b 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1496,6 +1496,7 @@ static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, DEFINE_MUTEX(fanout_mutex); EXPORT_SYMBOL_GPL(fanout_mutex); static LIST_HEAD(fanout_list); +static u16 fanout_next_id; static void __fanout_link(struct sock *sk, struct packet_sock *po) { @@ -1629,6 +1630,36 @@ static void fanout_release_data(struct packet_fanout *f) }; } +static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id) +{ + struct packet_fanout *f; + + list_for_each_entry(f, &fanout_list, list) { + if (f->id == candidate_id && + read_pnet(&f->net) == sock_net(sk)) { + return false; + } + } + return true; +} + +static bool fanout_find_new_id(struct sock *sk, u16 *new_id) +{ + u16 id = fanout_next_id; + + do { + if (__fanout_id_is_free(sk, id)) { + *new_id = id; + fanout_next_id = id + 1; + return true; + } + + id++; + } while (id != fanout_next_id); + + return false; +} + static int fanout_add(struct sock *sk, u16 id, u16 type_flags) { struct packet_rollover *rollover = NULL; @@ -1676,6 +1707,19 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags) po->rollover = rollover; } + if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) { + if (id != 0) { + err = -EINVAL; + goto out; + } + if (!fanout_find_new_id(sk, &id)) { + err = -ENOMEM; + goto out; + } + /* ephemeral flag for the first socket in the group: drop it */ + flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8); + } + match = NULL; list_for_each_entry(f, &fanout_list, list) { if (f->id == id && |