* UDP receive path is one user.
*/
unsigned long dev_scratch;
- int ip_defrag_offset;
};
};
- struct rb_node rbnode; /* used in netem & tcp stack */
+ struct rb_node rbnode; /* used in netem, ip4 defrag, and tcp stack */
+ struct list_head list;
+ };
+
+ union {
+ struct sock *sk;
+ int ip_defrag_offset;
};
- struct sock *sk;
union {
ktime_t tstamp;
struct timer_list timer;
spinlock_t lock;
refcount_t refcnt;
- struct sk_buff *fragments;
+ struct sk_buff *fragments; /* used in 6lopwpan IPv6. */
+ struct rb_root rb_fragments; /* Used in IPv4/IPv6. */
struct sk_buff *fragments_tail;
struct sk_buff *last_run_head;
ktime_t stamp;
extern const u8 ip_frag_ecn_table[16];
+/* Return values of inet_frag_queue_insert() */
+#define IPFRAG_OK 0
+#define IPFRAG_DUP 1
+#define IPFRAG_OVERLAP 2
+int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
+ int offset, int end);
+void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
+ struct sk_buff *parent);
+void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
+ void *reasm_data);
+struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q);
+
#endif
#include <net/sock.h>
#include <net/inet_frag.h>
#include <net/inet_ecn.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+
+/* Use skb->cb to track consecutive/adjacent fragments coming at
+ * the end of the queue. Nodes in the rb-tree queue will
+ * contain "runs" of one or more adjacent fragments.
+ *
+ * Invariants:
+ * - next_frag is NULL at the tail of a "run";
+ * - the head of a "run" has the sum of all fragment lengths in frag_run_len.
+ */
+struct ipfrag_skb_cb {
+ union {
+ struct inet_skb_parm h4;
+ struct inet6_skb_parm h6;
+ };
+ struct sk_buff *next_frag;
+ int frag_run_len;
+};
+
+#define FRAG_CB(skb) ((struct ipfrag_skb_cb *)((skb)->cb))
+
+static void fragcb_clear(struct sk_buff *skb)
+{
+ RB_CLEAR_NODE(&skb->rbnode);
+ FRAG_CB(skb)->next_frag = NULL;
+ FRAG_CB(skb)->frag_run_len = skb->len;
+}
+
+/* Append skb to the last "run". */
+static void fragrun_append_to_last(struct inet_frag_queue *q,
+ struct sk_buff *skb)
+{
+ fragcb_clear(skb);
+
+ FRAG_CB(q->last_run_head)->frag_run_len += skb->len;
+ FRAG_CB(q->fragments_tail)->next_frag = skb;
+ q->fragments_tail = skb;
+}
+
+/* Create a new "run" with the skb. */
+static void fragrun_create(struct inet_frag_queue *q, struct sk_buff *skb)
+{
+ BUILD_BUG_ON(sizeof(struct ipfrag_skb_cb) > sizeof(skb->cb));
+ fragcb_clear(skb);
+
+ if (q->last_run_head)
+ rb_link_node(&skb->rbnode, &q->last_run_head->rbnode,
+ &q->last_run_head->rbnode.rb_right);
+ else
+ rb_link_node(&skb->rbnode, NULL, &q->rb_fragments.rb_node);
+ rb_insert_color(&skb->rbnode, &q->rb_fragments);
+
+ q->fragments_tail = skb;
+ q->last_run_head = skb;
+}
/* Given the OR values of all fragments, apply RFC 3168 5.3 requirements
* Value : 0xff if frame should be dropped.
fp = q->fragments;
nf = q->net;
f = nf->f;
- while (fp) {
- struct sk_buff *xp = fp->next;
-
- sum_truesize += fp->truesize;
- kfree_skb(fp);
- fp = xp;
+ if (fp) {
+ do {
+ struct sk_buff *xp = fp->next;
+
+ sum_truesize += fp->truesize;
+ kfree_skb(fp);
+ fp = xp;
+ } while (fp);
+ } else {
+ sum_truesize = skb_rbtree_purge(&q->rb_fragments);
}
sum = sum_truesize + f->qsize;
return fq;
}
EXPORT_SYMBOL(inet_frag_find);
+
+int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb,
+ int offset, int end)
+{
+ struct sk_buff *last = q->fragments_tail;
+
+ /* RFC5722, Section 4, amended by Errata ID : 3089
+ * When reassembling an IPv6 datagram, if
+ * one or more its constituent fragments is determined to be an
+ * overlapping fragment, the entire datagram (and any constituent
+ * fragments) MUST be silently discarded.
+ *
+ * Duplicates, however, should be ignored (i.e. skb dropped, but the
+ * queue/fragments kept for later reassembly).
+ */
+ if (!last)
+ fragrun_create(q, skb); /* First fragment. */
+ else if (last->ip_defrag_offset + last->len < end) {
+ /* This is the common case: skb goes to the end. */
+ /* Detect and discard overlaps. */
+ if (offset < last->ip_defrag_offset + last->len)
+ return IPFRAG_OVERLAP;
+ if (offset == last->ip_defrag_offset + last->len)
+ fragrun_append_to_last(q, skb);
+ else
+ fragrun_create(q, skb);
+ } else {
+ /* Binary search. Note that skb can become the first fragment,
+ * but not the last (covered above).
+ */
+ struct rb_node **rbn, *parent;
+
+ rbn = &q->rb_fragments.rb_node;
+ do {
+ struct sk_buff *curr;
+ int curr_run_end;
+
+ parent = *rbn;
+ curr = rb_to_skb(parent);
+ curr_run_end = curr->ip_defrag_offset +
+ FRAG_CB(curr)->frag_run_len;
+ if (end <= curr->ip_defrag_offset)
+ rbn = &parent->rb_left;
+ else if (offset >= curr_run_end)
+ rbn = &parent->rb_right;
+ else if (offset >= curr->ip_defrag_offset &&
+ end <= curr_run_end)
+ return IPFRAG_DUP;
+ else
+ return IPFRAG_OVERLAP;
+ } while (*rbn);
+ /* Here we have parent properly set, and rbn pointing to
+ * one of its NULL left/right children. Insert skb.
+ */
+ fragcb_clear(skb);
+ rb_link_node(&skb->rbnode, parent, rbn);
+ rb_insert_color(&skb->rbnode, &q->rb_fragments);
+ }
+
+ skb->ip_defrag_offset = offset;
+
+ return IPFRAG_OK;
+}
+EXPORT_SYMBOL(inet_frag_queue_insert);
+
+void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb,
+ struct sk_buff *parent)
+{
+ struct sk_buff *fp, *head = skb_rb_first(&q->rb_fragments);
+ struct sk_buff **nextp;
+ int delta;
+
+ if (head != skb) {
+ fp = skb_clone(skb, GFP_ATOMIC);
+ if (!fp)
+ return NULL;
+ FRAG_CB(fp)->next_frag = FRAG_CB(skb)->next_frag;
+ if (RB_EMPTY_NODE(&skb->rbnode))
+ FRAG_CB(parent)->next_frag = fp;
+ else
+ rb_replace_node(&skb->rbnode, &fp->rbnode,
+ &q->rb_fragments);
+ if (q->fragments_tail == skb)
+ q->fragments_tail = fp;
+ skb_morph(skb, head);
+ FRAG_CB(skb)->next_frag = FRAG_CB(head)->next_frag;
+ rb_replace_node(&head->rbnode, &skb->rbnode,
+ &q->rb_fragments);
+ consume_skb(head);
+ head = skb;
+ }
+ WARN_ON(head->ip_defrag_offset != 0);
+
+ delta = -head->truesize;
+
+ /* Head of list must not be cloned. */
+ if (skb_unclone(head, GFP_ATOMIC))
+ return NULL;
+
+ delta += head->truesize;
+ if (delta)
+ add_frag_mem_limit(q->net, delta);
+
+ /* If the first fragment is fragmented itself, we split
+ * it to two chunks: the first with data and paged part
+ * and the second, holding only fragments.
+ */
+ if (skb_has_frag_list(head)) {
+ struct sk_buff *clone;
+ int i, plen = 0;
+
+ clone = alloc_skb(0, GFP_ATOMIC);
+ if (!clone)
+ return NULL;
+ skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
+ skb_frag_list_init(head);
+ for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
+ plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
+ clone->data_len = head->data_len - plen;
+ clone->len = clone->data_len;
+ head->truesize += clone->truesize;
+ clone->csum = 0;
+ clone->ip_summed = head->ip_summed;
+ add_frag_mem_limit(q->net, clone->truesize);
+ skb_shinfo(head)->frag_list = clone;
+ nextp = &clone->next;
+ } else {
+ nextp = &skb_shinfo(head)->frag_list;
+ }
+
+ return nextp;
+}
+EXPORT_SYMBOL(inet_frag_reasm_prepare);
+
+void inet_frag_reasm_finish(struct inet_frag_queue *q, struct sk_buff *head,
+ void *reasm_data)
+{
+ struct sk_buff **nextp = (struct sk_buff **)reasm_data;
+ struct rb_node *rbn;
+ struct sk_buff *fp;
+
+ skb_push(head, head->data - skb_network_header(head));
+
+ /* Traverse the tree in order, to build frag_list. */
+ fp = FRAG_CB(head)->next_frag;
+ rbn = rb_next(&head->rbnode);
+ rb_erase(&head->rbnode, &q->rb_fragments);
+ while (rbn || fp) {
+ /* fp points to the next sk_buff in the current run;
+ * rbn points to the next run.
+ */
+ /* Go through the current run. */
+ while (fp) {
+ *nextp = fp;
+ nextp = &fp->next;
+ fp->prev = NULL;
+ memset(&fp->rbnode, 0, sizeof(fp->rbnode));
+ fp->sk = NULL;
+ head->data_len += fp->len;
+ head->len += fp->len;
+ if (head->ip_summed != fp->ip_summed)
+ head->ip_summed = CHECKSUM_NONE;
+ else if (head->ip_summed == CHECKSUM_COMPLETE)
+ head->csum = csum_add(head->csum, fp->csum);
+ head->truesize += fp->truesize;
+ fp = FRAG_CB(fp)->next_frag;
+ }
+ /* Move to the next run. */
+ if (rbn) {
+ struct rb_node *rbnext = rb_next(rbn);
+
+ fp = rb_to_skb(rbn);
+ rb_erase(rbn, &q->rb_fragments);
+ rbn = rbnext;
+ }
+ }
+ sub_frag_mem_limit(q->net, head->truesize);
+
+ *nextp = NULL;
+ head->next = NULL;
+ head->prev = NULL;
+ head->tstamp = q->stamp;
+}
+EXPORT_SYMBOL(inet_frag_reasm_finish);
+
+struct sk_buff *inet_frag_pull_head(struct inet_frag_queue *q)
+{
+ struct sk_buff *head;
+
+ if (q->fragments) {
+ head = q->fragments;
+ q->fragments = head->next;
+ } else {
+ struct sk_buff *skb;
+
+ head = skb_rb_first(&q->rb_fragments);
+ if (!head)
+ return NULL;
+ skb = FRAG_CB(head)->next_frag;
+ if (skb)
+ rb_replace_node(&head->rbnode, &skb->rbnode,
+ &q->rb_fragments);
+ else
+ rb_erase(&head->rbnode, &q->rb_fragments);
+ memset(&head->rbnode, 0, sizeof(head->rbnode));
+ barrier();
+ }
+ if (head == q->fragments_tail)
+ q->fragments_tail = NULL;
+
+ sub_frag_mem_limit(q->net, head->truesize);
+
+ return head;
+}
+EXPORT_SYMBOL(inet_frag_pull_head);
{
struct inet_frag_queue *frag = from_timer(frag, t, timer);
const struct iphdr *iph;
- struct sk_buff *head;
+ struct sk_buff *head = NULL;
struct net *net;
struct ipq *qp;
int err;
ipq_kill(qp);
__IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS);
-
- head = qp->q.fragments;
-
__IP_INC_STATS(net, IPSTATS_MIB_REASMTIMEOUT);
- if (!(qp->q.flags & INET_FRAG_FIRST_IN) || !head)
+ if (!qp->q.flags & INET_FRAG_FIRST_IN)
goto out;
+ /* sk_buff::dev and sk_buff::rbnode are unionized. So we
+ * pull the head out of the tree in order to be able to
+ * deal with head->dev.
+ */
+ if (qp->q.fragments) {
+ head = qp->q.fragments;
+ qp->q.fragments = head->next;
+ } else {
+ head = skb_rb_first(&qp->q.rb_fragments);
+ if (!head)
+ goto out;
+ rb_erase(&head->rbnode, &qp->q.rb_fragments);
+ memset(&head->rbnode, 0, sizeof(head->rbnode));
+ barrier();
+ }
+ if (head == qp->q.fragments_tail)
+ qp->q.fragments_tail = NULL;
+
+ sub_frag_mem_limit(qp->q.net, head->truesize);
+
head->dev = dev_get_by_index_rcu(net, qp->iif);
if (!head->dev)
goto out;
(skb_rtable(head)->rt_type != RTN_LOCAL))
goto out;
- skb_get(head);
spin_unlock(&qp->q.lock);
icmp_send(head, ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0);
- kfree_skb(head);
goto out_rcu_unlock;
out:
spin_unlock(&qp->q.lock);
out_rcu_unlock:
rcu_read_unlock();
+ if (head)
+ kfree_skb(head);
ipq_put(qp);
}
end = atomic_inc_return(&peer->rid);
qp->rid = end;
- rc = qp->q.fragments && (end - start) > max;
+ rc = qp->q.fragments_tail && (end - start) > max;
if (rc) {
struct net *net;
static int ip_frag_reinit(struct ipq *qp)
{
- struct sk_buff *fp;
unsigned int sum_truesize = 0;
if (!mod_timer(&qp->q.timer, jiffies + qp->q.net->timeout)) {
return -ETIMEDOUT;
}
- fp = qp->q.fragments;
- do {
- struct sk_buff *xp = fp->next;
-
- sum_truesize += fp->truesize;
- kfree_skb(fp);
- fp = xp;
- } while (fp);
+ sum_truesize = skb_rbtree_purge(&qp->q.rb_fragments);
sub_frag_mem_limit(qp->q.net, sum_truesize);
qp->q.flags = 0;
qp->q.len = 0;
qp->q.meat = 0;
qp->q.fragments = NULL;
+ qp->q.rb_fragments = RB_ROOT;
qp->q.fragments_tail = NULL;
qp->iif = 0;
qp->ecn = 0;
static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb)
{
struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
- struct sk_buff *prev, *next;
+ struct rb_node **rbn, *parent;
+ struct sk_buff *skb1;
struct net_device *dev;
unsigned int fragsize;
int flags, offset;
if (err)
goto err;
- /* Find out which fragments are in front and at the back of us
- * in the chain of fragments so far. We must know where to put
- * this fragment, right?
- */
- prev = qp->q.fragments_tail;
- if (!prev || prev->ip_defrag_offset < offset) {
- next = NULL;
- goto found;
- }
- prev = NULL;
- for (next = qp->q.fragments; next != NULL; next = next->next) {
- if (next->ip_defrag_offset >= offset)
- break; /* bingo! */
- prev = next;
- }
+ /* Note : skb->rbnode and skb->dev share the same location. */
+ dev = skb->dev;
+ /* Makes sure compiler wont do silly aliasing games */
+ barrier();
-found:
/* RFC5722, Section 4, amended by Errata ID : 3089
* When reassembling an IPv6 datagram, if
* one or more its constituent fragments is determined to be an
* overlapping fragment, the entire datagram (and any constituent
* fragments) MUST be silently discarded.
*
- * We do the same here for IPv4.
+ * We do the same here for IPv4 (and increment an snmp counter).
*/
- /* Is there an overlap with the previous fragment? */
- if (prev &&
- (prev->ip_defrag_offset + prev->len) > offset)
- goto discard_qp;
-
- /* Is there an overlap with the next fragment? */
- if (next && next->ip_defrag_offset < end)
- goto discard_qp;
+ /* Find out where to put this fragment. */
+ skb1 = qp->q.fragments_tail;
+ if (!skb1) {
+ /* This is the first fragment we've received. */
+ rb_link_node(&skb->rbnode, NULL, &qp->q.rb_fragments.rb_node);
+ qp->q.fragments_tail = skb;
+ } else if ((skb1->ip_defrag_offset + skb1->len) < end) {
+ /* This is the common/special case: skb goes to the end. */
+ /* Detect and discard overlaps. */
+ if (offset < (skb1->ip_defrag_offset + skb1->len))
+ goto discard_qp;
+ /* Insert after skb1. */
+ rb_link_node(&skb->rbnode, &skb1->rbnode, &skb1->rbnode.rb_right);
+ qp->q.fragments_tail = skb;
+ } else {
+ /* Binary search. Note that skb can become the first fragment, but
+ * not the last (covered above). */
+ rbn = &qp->q.rb_fragments.rb_node;
+ do {
+ parent = *rbn;
+ skb1 = rb_to_skb(parent);
+ if (end <= skb1->ip_defrag_offset)
+ rbn = &parent->rb_left;
+ else if (offset >= skb1->ip_defrag_offset + skb1->len)
+ rbn = &parent->rb_right;
+ else /* Found an overlap with skb1. */
+ goto discard_qp;
+ } while (*rbn);
+ /* Here we have parent properly set, and rbn pointing to
+ * one of its NULL left/right children. Insert skb. */
+ rb_link_node(&skb->rbnode, parent, rbn);
+ }
+ rb_insert_color(&skb->rbnode, &qp->q.rb_fragments);
- /* Note : skb->ip_defrag_offset and skb->dev share the same location */
- dev = skb->dev;
if (dev)
qp->iif = dev->ifindex;
- /* Makes sure compiler wont do silly aliasing games */
- barrier();
skb->ip_defrag_offset = offset;
- /* Insert this fragment in the chain of fragments. */
- skb->next = next;
- if (!next)
- qp->q.fragments_tail = skb;
- if (prev)
- prev->next = skb;
- else
- qp->q.fragments = skb;
-
qp->q.stamp = skb->tstamp;
qp->q.meat += skb->len;
qp->ecn |= ecn;
unsigned long orefdst = skb->_skb_refdst;
skb->_skb_refdst = 0UL;
- err = ip_frag_reasm(qp, prev, dev);
+ err = ip_frag_reasm(qp, skb, dev);
skb->_skb_refdst = orefdst;
return err;
}
return err;
}
-
/* Build a new IP datagram from all its fragments. */
-
-static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
+static int ip_frag_reasm(struct ipq *qp, struct sk_buff *skb,
struct net_device *dev)
{
struct net *net = container_of(qp->q.net, struct net, ipv4.frags);
struct iphdr *iph;
- struct sk_buff *fp, *head = qp->q.fragments;
+ struct sk_buff *fp, *head = skb_rb_first(&qp->q.rb_fragments);
+ struct sk_buff **nextp; /* To build frag_list. */
+ struct rb_node *rbn;
int len;
int ihlen;
int delta;
goto out_fail;
}
/* Make the one we just received the head. */
- if (prev) {
- head = prev->next;
- fp = skb_clone(head, GFP_ATOMIC);
+ if (head != skb) {
+ fp = skb_clone(skb, GFP_ATOMIC);
if (!fp)
goto out_nomem;
-
- fp->next = head->next;
- if (!fp->next)
+ rb_replace_node(&skb->rbnode, &fp->rbnode, &qp->q.rb_fragments);
+ if (qp->q.fragments_tail == skb)
qp->q.fragments_tail = fp;
- prev->next = fp;
-
- skb_morph(head, qp->q.fragments);
- head->next = qp->q.fragments->next;
-
- consume_skb(qp->q.fragments);
- qp->q.fragments = head;
+ skb_morph(skb, head);
+ rb_replace_node(&head->rbnode, &skb->rbnode,
+ &qp->q.rb_fragments);
+ consume_skb(head);
+ head = skb;
}
- WARN_ON(!head);
WARN_ON(head->ip_defrag_offset != 0);
/* Allocate a new buffer for the datagram. */
clone = alloc_skb(0, GFP_ATOMIC);
if (!clone)
goto out_nomem;
- clone->next = head->next;
- head->next = clone;
skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
skb_frag_list_init(head);
for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
clone->len = clone->data_len = head->data_len - plen;
- head->data_len -= clone->len;
- head->len -= clone->len;
+ skb->truesize += clone->truesize;
clone->csum = 0;
clone->ip_summed = head->ip_summed;
add_frag_mem_limit(qp->q.net, clone->truesize);
+ skb_shinfo(head)->frag_list = clone;
+ nextp = &clone->next;
+ } else {
+ nextp = &skb_shinfo(head)->frag_list;
}
- skb_shinfo(head)->frag_list = head->next;
skb_push(head, head->data - skb_network_header(head));
- for (fp=head->next; fp; fp = fp->next) {
+ /* Traverse the tree in order, to build frag_list. */
+ rbn = rb_next(&head->rbnode);
+ rb_erase(&head->rbnode, &qp->q.rb_fragments);
+ while (rbn) {
+ struct rb_node *rbnext = rb_next(rbn);
+ fp = rb_to_skb(rbn);
+ rb_erase(rbn, &qp->q.rb_fragments);
+ rbn = rbnext;
+ *nextp = fp;
+ nextp = &fp->next;
+ fp->prev = NULL;
+ memset(&fp->rbnode, 0, sizeof(fp->rbnode));
head->data_len += fp->len;
head->len += fp->len;
if (head->ip_summed != fp->ip_summed)
}
sub_frag_mem_limit(qp->q.net, head->truesize);
+ *nextp = NULL;
head->next = NULL;
+ head->prev = NULL;
head->dev = dev;
head->tstamp = qp->q.stamp;
IPCB(head)->frag_max_size = max(qp->max_df_size, qp->q.max_size);
__IP_INC_STATS(net, IPSTATS_MIB_REASMOKS);
qp->q.fragments = NULL;
+ qp->q.rb_fragments = RB_ROOT;
qp->q.fragments_tail = NULL;
return 0;
head->csum);
fq->q.fragments = NULL;
+ fq->q.rb_fragments = RB_ROOT;
fq->q.fragments_tail = NULL;
return true;
__IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
rcu_read_unlock();
fq->q.fragments = NULL;
+ fq->q.rb_fragments = RB_ROOT;
fq->q.fragments_tail = NULL;
return 1;
projects / mirror_ubuntu-bionic-kernel.git / commitdiff