Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...
[firefly-linux-kernel-4.4.55.git] / net / ipv4 / inet_fragment.c
index f4fd23de9b13103b10351310aea08c47d0429d38..7e06641e36ae785239f32b1d5afb80e504e0c60b 100644 (file)
 
 #include <net/sock.h>
 #include <net/inet_frag.h>
+#include <net/inet_ecn.h>
+
+/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements
+ * Value : 0xff if frame should be dropped.
+ *         0 or INET_ECN_CE value, to be ORed in to final iph->tos field
+ */
+const u8 ip_frag_ecn_table[16] = {
+       /* at least one fragment had CE, and others ECT_0 or ECT_1 */
+       [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0]                      = INET_ECN_CE,
+       [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1]                      = INET_ECN_CE,
+       [IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1]   = INET_ECN_CE,
+
+       /* invalid combinations : drop frame */
+       [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE] = 0xff,
+       [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0] = 0xff,
+       [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_1] = 0xff,
+       [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
+       [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0] = 0xff,
+       [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_1] = 0xff,
+       [IPFRAG_ECN_NOT_ECT | IPFRAG_ECN_CE | IPFRAG_ECN_ECT_0 | IPFRAG_ECN_ECT_1] = 0xff,
+};
+EXPORT_SYMBOL(ip_frag_ecn_table);
 
 static void inet_frag_secret_rebuild(unsigned long dummy)
 {
@@ -30,20 +52,27 @@ static void inet_frag_secret_rebuild(unsigned long dummy)
        unsigned long now = jiffies;
        int i;
 
+       /* Per bucket lock NOT needed here, due to write lock protection */
        write_lock(&f->lock);
+
        get_random_bytes(&f->rnd, sizeof(u32));
        for (i = 0; i < INETFRAGS_HASHSZ; i++) {
+               struct inet_frag_bucket *hb;
                struct inet_frag_queue *q;
                struct hlist_node *n;
 
-               hlist_for_each_entry_safe(q, n, &f->hash[i], list) {
+               hb = &f->hash[i];
+               hlist_for_each_entry_safe(q, n, &hb->chain, list) {
                        unsigned int hval = f->hashfn(q);
 
                        if (hval != i) {
+                               struct inet_frag_bucket *hb_dest;
+
                                hlist_del(&q->list);
 
                                /* Relink to new hash chain. */
-                               hlist_add_head(&q->list, &f->hash[hval]);
+                               hb_dest = &f->hash[hval];
+                               hlist_add_head(&q->list, &hb_dest->chain);
                        }
                }
        }
@@ -56,9 +85,12 @@ void inet_frags_init(struct inet_frags *f)
 {
        int i;
 
-       for (i = 0; i < INETFRAGS_HASHSZ; i++)
-               INIT_HLIST_HEAD(&f->hash[i]);
+       for (i = 0; i < INETFRAGS_HASHSZ; i++) {
+               struct inet_frag_bucket *hb = &f->hash[i];
 
+               spin_lock_init(&hb->chain_lock);
+               INIT_HLIST_HEAD(&hb->chain);
+       }
        rwlock_init(&f->lock);
 
        f->rnd = (u32) ((num_physpages ^ (num_physpages>>7)) ^
@@ -100,10 +132,18 @@ EXPORT_SYMBOL(inet_frags_exit_net);
 
 static inline void fq_unlink(struct inet_frag_queue *fq, struct inet_frags *f)
 {
-       write_lock(&f->lock);
+       struct inet_frag_bucket *hb;
+       unsigned int hash;
+
+       read_lock(&f->lock);
+       hash = f->hashfn(fq);
+       hb = &f->hash[hash];
+
+       spin_lock(&hb->chain_lock);
        hlist_del(&fq->list);
-       fq->net->nqueues--;
-       write_unlock(&f->lock);
+       spin_unlock(&hb->chain_lock);
+
+       read_unlock(&f->lock);
        inet_frag_lru_del(fq);
 }
 
@@ -182,6 +222,9 @@ int inet_frag_evictor(struct netns_frags *nf, struct inet_frags *f, bool force)
                q = list_first_entry(&nf->lru_list,
                                struct inet_frag_queue, lru_list);
                atomic_inc(&q->refcnt);
+               /* Remove q from list to avoid several CPUs grabbing it */
+               list_del_init(&q->lru_list);
+
                spin_unlock(&nf->lru_lock);
 
                spin_lock(&q->lock);
@@ -202,27 +245,32 @@ static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf,
                struct inet_frag_queue *qp_in, struct inet_frags *f,
                void *arg)
 {
+       struct inet_frag_bucket *hb;
        struct inet_frag_queue *qp;
 #ifdef CONFIG_SMP
 #endif
        unsigned int hash;
 
-       write_lock(&f->lock);
+       read_lock(&f->lock); /* Protects against hash rebuild */
        /*
         * While we stayed w/o the lock other CPU could update
         * the rnd seed, so we need to re-calculate the hash
         * chain. Fortunatelly the qp_in can be used to get one.
         */
        hash = f->hashfn(qp_in);
+       hb = &f->hash[hash];
+       spin_lock(&hb->chain_lock);
+
 #ifdef CONFIG_SMP
        /* With SMP race we have to recheck hash table, because
         * such entry could be created on other cpu, while we
-        * promoted read lock to write lock.
+        * released the hash bucket lock.
         */
-       hlist_for_each_entry(qp, &f->hash[hash], list) {
+       hlist_for_each_entry(qp, &hb->chain, list) {
                if (qp->net == nf && f->match(qp, arg)) {
                        atomic_inc(&qp->refcnt);
-                       write_unlock(&f->lock);
+                       spin_unlock(&hb->chain_lock);
+                       read_unlock(&f->lock);
                        qp_in->last_in |= INET_FRAG_COMPLETE;
                        inet_frag_put(qp_in, f);
                        return qp;
@@ -234,9 +282,9 @@ static struct inet_frag_queue *inet_frag_intern(struct netns_frags *nf,
                atomic_inc(&qp->refcnt);
 
        atomic_inc(&qp->refcnt);
-       hlist_add_head(&qp->list, &f->hash[hash]);
-       nf->nqueues++;
-       write_unlock(&f->lock);
+       hlist_add_head(&qp->list, &hb->chain);
+       spin_unlock(&hb->chain_lock);
+       read_unlock(&f->lock);
        inet_frag_lru_add(nf, qp);
        return qp;
 }
@@ -257,6 +305,7 @@ static struct inet_frag_queue *inet_frag_alloc(struct netns_frags *nf,
        setup_timer(&q->timer, f->frag_expire, (unsigned long)q);
        spin_lock_init(&q->lock);
        atomic_set(&q->refcnt, 1);
+       INIT_LIST_HEAD(&q->lru_list);
 
        return q;
 }
@@ -277,17 +326,23 @@ struct inet_frag_queue *inet_frag_find(struct netns_frags *nf,
                struct inet_frags *f, void *key, unsigned int hash)
        __releases(&f->lock)
 {
+       struct inet_frag_bucket *hb;
        struct inet_frag_queue *q;
        int depth = 0;
 
-       hlist_for_each_entry(q, &f->hash[hash], list) {
+       hb = &f->hash[hash];
+
+       spin_lock(&hb->chain_lock);
+       hlist_for_each_entry(q, &hb->chain, list) {
                if (q->net == nf && f->match(q, key)) {
                        atomic_inc(&q->refcnt);
+                       spin_unlock(&hb->chain_lock);
                        read_unlock(&f->lock);
                        return q;
                }
                depth++;
        }
+       spin_unlock(&hb->chain_lock);
        read_unlock(&f->lock);
 
        if (depth <= INETFRAGS_MAXDEPTH)