7 files changed, 160 insertions, 68 deletions

diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c
index 8f485a0d14bd..22371185efb6 100644
--- a/net/sctp/endpointola.c
+++ b/net/sctp/endpointola.c
@@ -102,6 +102,7 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 
         /* Use SCTP specific send buffer space queues.  */
         ep->sndbuf_policy = sctp_sndbuf_policy;
+
         sk->sk_write_space = sctp_write_space;
         sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
 
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 3d036cdfae41..957c118a6068 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -51,6 +51,7 @@
 #include <linux/netdevice.h>
 #include <linux/inetdevice.h>
 #include <linux/seq_file.h>
+#include <linux/bootmem.h>
 #include <net/protocol.h>
 #include <net/ip.h>
 #include <net/ipv6.h>
@@ -82,6 +83,10 @@ static struct sctp_af *sctp_af_v6_specific;
 struct kmem_cache *sctp_chunk_cachep __read_mostly;
 struct kmem_cache *sctp_bucket_cachep __read_mostly;
 
+extern int sysctl_sctp_mem[3];
+extern int sysctl_sctp_rmem[3];
+extern int sysctl_sctp_wmem[3];
+
 /* Return the address of the control sock. */
 struct sock *sctp_get_ctl_sock(void)
 {
@@ -987,6 +992,8 @@ SCTP_STATIC __init int sctp_init(void)
         int i;
         int status = -EINVAL;
         unsigned long goal;
+        unsigned long limit;
+        int max_share;
         int order;
 
         /* SCTP_DEBUG sanity check. */
@@ -1077,6 +1084,31 @@ SCTP_STATIC __init int sctp_init(void)
         /* Initialize handle used for association ids. */
         idr_init(&sctp_assocs_id);
 
+        /* Set the pressure threshold to be a fraction of global memory that
+         * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
+         * memory, with a floor of 128 pages.
+         * Note this initalizes the data in sctpv6_prot too
+         * Unabashedly stolen from tcp_init
+         */
+        limit = min(num_physpages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
+        limit = (limit * (num_physpages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
+        limit = max(limit, 128UL);
+        sysctl_sctp_mem[0] = limit / 4 * 3;
+        sysctl_sctp_mem[1] = limit;
+        sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;
+
+        /* Set per-socket limits to no more than 1/128 the pressure threshold*/
+        limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
+        max_share = min(4UL*1024*1024, limit);
+
+        sysctl_sctp_rmem[0] = PAGE_SIZE; /* give each asoc 1 page min */
+        sysctl_sctp_rmem[1] = (1500 *(sizeof(struct sk_buff) + 1));
+        sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
+
+        sysctl_sctp_wmem[0] = SK_STREAM_MEM_QUANTUM;
+        sysctl_sctp_wmem[1] = 16*1024;
+        sysctl_sctp_wmem[2] = max(64*1024, max_share);
+
         /* Size and allocate the association hash table.
          * The methodology is similar to that of the tcp hash tables.
          */
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index a583d67cab63..ec0328b1cdb1 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -5428,10 +5428,8 @@ static int sctp_eat_data(const struct sctp_association *asoc,
         sctp_verb_t deliver;
         int tmp;
         __u32 tsn;
-        int account_value;
         struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
         struct sock *sk = asoc->base.sk;
-        int rcvbuf_over = 0;
 
         data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
         skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
@@ -5441,48 +5439,6 @@ static int sctp_eat_data(const struct sctp_association *asoc,
 
         /* ASSERT:  Now skb->data is really the user data.  */
 
-        /*
-         * If we are established, and we have used up our receive buffer
-         * memory, think about droping the frame.
-         * Note that we have an opportunity to improve performance here.
-         * If we accept one chunk from an skbuff, we have to keep all the
-         * memory of that skbuff around until the chunk is read into user
-         * space. Therefore, once we accept 1 chunk we may as well accept all
-         * remaining chunks in the skbuff. The data_accepted flag helps us do
-         * that.
-         */
-        if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
-                /*
-                 * If the receive buffer policy is 1, then each
-                 * association can allocate up to sk_rcvbuf bytes
-                 * otherwise, all the associations in aggregate
-                 * may allocate up to sk_rcvbuf bytes
-                 */
-                if (asoc->ep->rcvbuf_policy)
-                        account_value = atomic_read(&asoc->rmem_alloc);
-                else
-                        account_value = atomic_read(&sk->sk_rmem_alloc);
-                if (account_value > sk->sk_rcvbuf) {
-                        /*
-                         * We need to make forward progress, even when we are
-                         * under memory pressure, so we always allow the
-                         * next tsn after the ctsn ack point to be accepted.
-                         * This lets us avoid deadlocks in which we have to
-                         * drop frames that would otherwise let us drain the
-                         * receive queue.
-                         */
-                        if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
-                                return SCTP_IERROR_IGNORE_TSN;
-
-                        /*
-                         * We're going to accept the frame but we should renege
-                         * to make space for it. This will send us down that
-                         * path later in this function.
-                         */
-                        rcvbuf_over = 1;
-                }
-        }
-
         /* Process ECN based congestion.
          *
          * Since the chunk structure is reused for all chunks within
@@ -5542,18 +5498,9 @@ static int sctp_eat_data(const struct sctp_association *asoc,
          * seems a bit troublesome in that frag_point varies based on
          * PMTU.  In cases, such as loopback, this might be a rather
          * large spill over.
-         * NOTE: If we have a full receive buffer here, we only renege if
-         * our receiver can still make progress without the tsn being
-         * received. We do this because in the event that the associations
-         * receive queue is empty we are filling a leading gap, and since
-         * reneging moves the gap to the end of the tsn stream, we are likely
-         * to stall again very shortly. Avoiding the renege when we fill a
-         * leading gap is a good heuristic for avoiding such steady state
-         * stalls.
-         */
-        if (!asoc->rwnd || asoc->rwnd_over ||
-            (datalen > asoc->rwnd + asoc->frag_point) ||
-            (rcvbuf_over && (!skb_queue_len(&sk->sk_receive_queue)))) {
+         */
+        if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
+            (datalen > asoc->rwnd + asoc->frag_point))) {
 
                 /* If this is the next TSN, consider reneging to make
                  * room.   Note: Playing nice with a confused sender.  A
@@ -5574,6 +5521,21 @@ static int sctp_eat_data(const struct sctp_association *asoc,
         }
 
         /*
+         * Also try to renege to limit our memory usage in the event that
+         * we are under memory pressure
+         * If we can't renege, don't worry about it, the sk_stream_rmem_schedule
+         * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
+         * memory usage too much
+         */
+        if (*sk->sk_prot_creator->memory_pressure) {
+                if (sctp_tsnmap_has_gap(map) &&
+                   (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
+                        SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
+                        deliver = SCTP_CMD_RENEGE;
+                 }
+        }
+
+        /*
          * Section 3.3.10.9 No User Data (9)
          *
          * Cause of error
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 772fbfb4bfda..b9952425c79a 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -107,23 +107,42 @@ static void sctp_sock_migrate(struct sock *, struct sock *,
                               struct sctp_association *, sctp_socket_type_t);
 static char *sctp_hmac_alg = SCTP_COOKIE_HMAC_ALG;
 
+extern struct kmem_cache *sctp_bucket_cachep;
+extern int sysctl_sctp_mem[3];
+extern int sysctl_sctp_rmem[3];
+extern int sysctl_sctp_wmem[3];
+
+int sctp_memory_pressure;
+atomic_t sctp_memory_allocated;
+atomic_t sctp_sockets_allocated;
+
+static void sctp_enter_memory_pressure(void)
+{
+        sctp_memory_pressure = 1;
+}
+
+
 /* Get the sndbuf space available at the time on the association.  */
 static inline int sctp_wspace(struct sctp_association *asoc)
 {
-        struct sock *sk = asoc->base.sk;
-        int amt = 0;
+        int amt;
 
-        if (asoc->ep->sndbuf_policy) {
-                /* make sure that no association uses more than sk_sndbuf */
-                amt = sk->sk_sndbuf - asoc->sndbuf_used;
+        if (asoc->ep->sndbuf_policy)
+                amt = asoc->sndbuf_used;
+        else
+                amt = atomic_read(&asoc->base.sk->sk_wmem_alloc);
+
+        if (amt >= asoc->base.sk->sk_sndbuf) {
+                if (asoc->base.sk->sk_userlocks & SOCK_SNDBUF_LOCK)
+                        amt = 0;
+                else {
+                        amt = sk_stream_wspace(asoc->base.sk);
+                        if (amt < 0)
+                                amt = 0;
+                }
         } else {
-                /* do socket level accounting */
-                amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
+                amt = asoc->base.sk->sk_sndbuf - amt;
         }
-
-        if (amt < 0)
-                amt = 0;
-
         return amt;
 }
 
@@ -155,6 +174,7 @@ static inline void sctp_set_owner_w(struct sctp_chunk *chunk)
                                 sizeof(struct sctp_chunk);
 
         atomic_add(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
+        sk_charge_skb(sk, chunk->skb);
 }
 
 /* Verify that this is a valid address. */
@@ -3293,6 +3313,7 @@ SCTP_STATIC int sctp_init_sock(struct sock *sk)
         sp->hmac = NULL;
 
         SCTP_DBG_OBJCNT_INC(sock);
+        atomic_inc(&sctp_sockets_allocated);
         return 0;
 }
 
@@ -3306,7 +3327,7 @@ SCTP_STATIC int sctp_destroy_sock(struct sock *sk)
         /* Release our hold on the endpoint. */
         ep = sctp_sk(sk)->ep;
         sctp_endpoint_free(ep);
-
+        atomic_dec(&sctp_sockets_allocated);
         return 0;
 }
 
@@ -5720,6 +5741,12 @@ static void sctp_wfree(struct sk_buff *skb)
 
         atomic_sub(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
 
+        /*
+         * This undoes what is done via sk_charge_skb
+         */
+        sk->sk_wmem_queued   -= skb->truesize;
+        sk->sk_forward_alloc += skb->truesize;
+
         sock_wfree(skb);
         __sctp_write_space(asoc);
 
@@ -5737,6 +5764,11 @@ void sctp_sock_rfree(struct sk_buff *skb)
         struct sctp_ulpevent *event = sctp_skb2event(skb);
 
         atomic_sub(event->rmem_len, &sk->sk_rmem_alloc);
+
+        /*
+         * Mimic the behavior of sk_stream_rfree
+         */
+        sk->sk_forward_alloc += event->rmem_len;
 }
 
 
@@ -6126,6 +6158,7 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
         sctp_release_sock(newsk);
 }
 
+
 /* This proto struct describes the ULP interface for SCTP.  */
 struct proto sctp_prot = {
         .name        =  "SCTP",
@@ -6148,6 +6181,12 @@ struct proto sctp_prot = {
         .unhash      =  sctp_unhash,
         .get_port    =  sctp_get_port,
         .obj_size    =  sizeof(struct sctp_sock),
+        .sysctl_mem  =  sysctl_sctp_mem,
+        .sysctl_rmem =  sysctl_sctp_rmem,
+        .sysctl_wmem =  sysctl_sctp_wmem,
+        .memory_pressure = &sctp_memory_pressure,
+        .enter_memory_pressure = sctp_enter_memory_pressure,
+        .memory_allocated = &sctp_memory_allocated,
 };
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -6172,5 +6211,11 @@ struct proto sctpv6_prot = {
         .unhash         = sctp_unhash,
         .get_port       = sctp_get_port,
         .obj_size       = sizeof(struct sctp6_sock),
+        .sysctl_mem     = sysctl_sctp_mem,
+        .sysctl_rmem    = sysctl_sctp_rmem,
+        .sysctl_wmem    = sysctl_sctp_wmem,
+        .memory_pressure = &sctp_memory_pressure,
+        .enter_memory_pressure = sctp_enter_memory_pressure,
+        .memory_allocated = &sctp_memory_allocated,
 };
 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c
index e2c679baf912..ba75ef4669e3 100644
--- a/net/sctp/sysctl.c
+++ b/net/sctp/sysctl.c
@@ -52,6 +52,15 @@ static int int_max = INT_MAX;
 static long sack_timer_min = 1;
 static long sack_timer_max = 500;
 
+int sysctl_sctp_mem[3];
+int sysctl_sctp_rmem[3];
+int sysctl_sctp_wmem[3];
+
+/*
+ * per assoc memory limitationf for sends
+ */
+int sysctl_sctp_wmem[3];
+
 static ctl_table sctp_table[] = {
         {
                 .ctl_name       = NET_SCTP_RTO_INITIAL,
@@ -226,6 +235,30 @@ static ctl_table sctp_table[] = {
                 .extra1         = &sack_timer_min,
                 .extra2         = &sack_timer_max,
         },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "sctp_mem",
+                .data           = &sysctl_sctp_mem,
+                .maxlen         = sizeof(sysctl_sctp_mem),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "sctp_rmem",
+                .data           = &sysctl_sctp_rmem,
+                .maxlen         = sizeof(sysctl_sctp_rmem),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
+        {
+                .ctl_name       = CTL_UNNUMBERED,
+                .procname       = "sctp_wmem",
+                .data           = &sysctl_sctp_wmem,
+                .maxlen         = sizeof(sysctl_sctp_wmem),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec,
+        },
         { .ctl_name = 0 }
 };
 
diff --git a/net/sctp/ulpevent.c b/net/sctp/ulpevent.c
index bfecb353ab3d..5dc094b9732d 100644
--- a/net/sctp/ulpevent.c
+++ b/net/sctp/ulpevent.c
@@ -685,6 +685,24 @@ struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
         struct sctp_ulpevent *event = NULL;
         struct sk_buff *skb;
         size_t padding, len;
+        int rx_count;
+
+        /*
+         * check to see if we need to make space for this
+         * new skb, expand the rcvbuffer if needed, or drop
+         * the frame
+         */
+        if (asoc->ep->rcvbuf_policy)
+                rx_count = atomic_read(&asoc->rmem_alloc);
+        else
+                rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
+
+        if (rx_count >= asoc->base.sk->sk_rcvbuf) {
+
+                if ((asoc->base.sk->sk_userlocks & SOCK_RCVBUF_LOCK) ||
+                   (!sk_stream_rmem_schedule(asoc->base.sk, chunk->skb)))
+                        goto fail;
+        }
 
         /* Clone the original skb, sharing the data.  */
         skb = skb_clone(chunk->skb, gfp);
diff --git a/net/sctp/ulpqueue.c b/net/sctp/ulpqueue.c
index fa0ba2a5564e..b9370956b187 100644
--- a/net/sctp/ulpqueue.c
+++ b/net/sctp/ulpqueue.c
@@ -1027,6 +1027,7 @@ void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
                 sctp_ulpq_partial_delivery(ulpq, chunk, gfp);
         }
 
+        sk_stream_mem_reclaim(asoc->base.sk);
         return;
 }