From 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Tue, 15 Dec 2015 14:52:16 -0300 Subject: Linux-libre 4.3.2-gnu --- net/netlink/af_netlink.c | 96 +++++++++++++++++++++++++++++++++--------------- 1 file changed, 67 insertions(+), 29 deletions(-) (limited to 'net/netlink') diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index a133d16eb..fafe33bdb 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -84,6 +84,7 @@ struct listeners { #define NETLINK_F_BROADCAST_SEND_ERROR 0x4 #define NETLINK_F_RECV_NO_ENOBUFS 0x8 #define NETLINK_F_LISTEN_ALL_NSID 0x10 +#define NETLINK_F_CAP_ACK 0x20 static inline int netlink_is_kernel(struct sock *sk) { @@ -610,16 +611,6 @@ netlink_current_frame(const struct netlink_ring *ring, return netlink_lookup_frame(ring, ring->head, status); } -static struct nl_mmap_hdr * -netlink_previous_frame(const struct netlink_ring *ring, - enum nl_mmap_status status) -{ - unsigned int prev; - - prev = ring->head ? ring->head - 1 : ring->frame_max; - return netlink_lookup_frame(ring, prev, status); -} - static void netlink_increment_head(struct netlink_ring *ring) { ring->head = ring->head != ring->frame_max ? ring->head + 1 : 0; @@ -627,11 +618,11 @@ static void netlink_increment_head(struct netlink_ring *ring) static void netlink_forward_ring(struct netlink_ring *ring) { - unsigned int head = ring->head, pos = head; + unsigned int head = ring->head; const struct nl_mmap_hdr *hdr; do { - hdr = __netlink_lookup_frame(ring, pos); + hdr = __netlink_lookup_frame(ring, ring->head); if (hdr->nm_status == NL_MMAP_STATUS_UNUSED) break; if (hdr->nm_status != NL_MMAP_STATUS_SKIP) @@ -640,6 +631,21 @@ static void netlink_forward_ring(struct netlink_ring *ring) } while (ring->head != head); } +static bool netlink_has_valid_frame(struct netlink_ring *ring) +{ + unsigned int head = ring->head, pos = head; + const struct nl_mmap_hdr *hdr; + + do { + hdr = __netlink_lookup_frame(ring, pos); + if (hdr->nm_status == NL_MMAP_STATUS_VALID) + return true; + pos = pos != 0 ? pos - 1 : ring->frame_max; + } while (pos != head); + + return false; +} + static bool netlink_dump_space(struct netlink_sock *nlk) { struct netlink_ring *ring = &nlk->rx_ring; @@ -685,13 +691,19 @@ static unsigned int netlink_poll(struct file *file, struct socket *sock, mask = datagram_poll(file, sock, wait); - spin_lock_bh(&sk->sk_receive_queue.lock); - if (nlk->rx_ring.pg_vec) { - netlink_forward_ring(&nlk->rx_ring); - if (!netlink_previous_frame(&nlk->rx_ring, NL_MMAP_STATUS_UNUSED)) - mask |= POLLIN | POLLRDNORM; + /* We could already have received frames in the normal receive + * queue, that will show up as NL_MMAP_STATUS_COPY in the ring, + * so if mask contains pollin/etc already, there's no point + * walking the ring. + */ + if ((mask & (POLLIN | POLLRDNORM)) != (POLLIN | POLLRDNORM)) { + spin_lock_bh(&sk->sk_receive_queue.lock); + if (nlk->rx_ring.pg_vec) { + if (netlink_has_valid_frame(&nlk->rx_ring)) + mask |= POLLIN | POLLRDNORM; + } + spin_unlock_bh(&sk->sk_receive_queue.lock); } - spin_unlock_bh(&sk->sk_receive_queue.lock); spin_lock_bh(&sk->sk_write_queue.lock); if (nlk->tx_ring.pg_vec) { @@ -1864,15 +1876,16 @@ retry: } EXPORT_SYMBOL(netlink_unicast); -struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size, - u32 dst_portid, gfp_t gfp_mask) +struct sk_buff *__netlink_alloc_skb(struct sock *ssk, unsigned int size, + unsigned int ldiff, u32 dst_portid, + gfp_t gfp_mask) { #ifdef CONFIG_NETLINK_MMAP + unsigned int maxlen, linear_size; struct sock *sk = NULL; struct sk_buff *skb; struct netlink_ring *ring; struct nl_mmap_hdr *hdr; - unsigned int maxlen; sk = netlink_getsockbyportid(ssk, dst_portid); if (IS_ERR(sk)) @@ -1883,7 +1896,11 @@ struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size, if (ring->pg_vec == NULL) goto out_put; - if (ring->frame_size - NL_MMAP_HDRLEN < size) + /* We need to account the full linear size needed as a ring + * slot cannot have non-linear parts. + */ + linear_size = size + ldiff; + if (ring->frame_size - NL_MMAP_HDRLEN < linear_size) goto out_put; skb = alloc_skb_head(gfp_mask); @@ -1897,13 +1914,14 @@ struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size, /* check again under lock */ maxlen = ring->frame_size - NL_MMAP_HDRLEN; - if (maxlen < size) + if (maxlen < linear_size) goto out_free; netlink_forward_ring(ring); hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED); if (hdr == NULL) goto err2; + netlink_ring_setup_skb(skb, sk, ring, hdr); netlink_set_status(hdr, NL_MMAP_STATUS_RESERVED); atomic_inc(&ring->pending); @@ -1929,7 +1947,7 @@ out: #endif return alloc_skb(size, gfp_mask); } -EXPORT_SYMBOL_GPL(netlink_alloc_skb); +EXPORT_SYMBOL_GPL(__netlink_alloc_skb); int netlink_has_listeners(struct sock *sk, unsigned int group) { @@ -2290,6 +2308,13 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname, nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID; err = 0; break; + case NETLINK_CAP_ACK: + if (val) + nlk->flags |= NETLINK_F_CAP_ACK; + else + nlk->flags &= ~NETLINK_F_CAP_ACK; + err = 0; + break; default: err = -ENOPROTOOPT; } @@ -2346,7 +2371,7 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname, int pos, idx, shift; err = 0; - netlink_table_grab(); + netlink_lock_table(); for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { if (len - pos < sizeof(u32)) break; @@ -2361,9 +2386,19 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname, } if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen)) err = -EFAULT; - netlink_table_ungrab(); + netlink_unlock_table(); break; } + case NETLINK_CAP_ACK: + if (len < sizeof(int)) + return -EINVAL; + len = sizeof(int); + val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0; + if (put_user(len, optlen) || + put_user(val, optval)) + return -EFAULT; + err = 0; + break; default: err = -ENOPROTOOPT; } @@ -2918,9 +2953,12 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) struct nlmsghdr *rep; struct nlmsgerr *errmsg; size_t payload = sizeof(*errmsg); + struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); - /* error messages get the original request appened */ - if (err) + /* Error messages get the original request appened, unless the user + * requests to cap the error message. + */ + if (!(nlk->flags & NETLINK_F_CAP_ACK) && err) payload += nlmsg_len(nlh); skb = netlink_alloc_skb(in_skb->sk, nlmsg_total_size(payload), @@ -2943,7 +2981,7 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err) NLMSG_ERROR, payload, 0); errmsg = nlmsg_data(rep); errmsg->error = err; - memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh)); + memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh)); netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT); } EXPORT_SYMBOL(netlink_ack); -- cgit v1.2.3