/* Functions for managing the dp interface/device. */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
static struct datapath *dps[ODP_MAX];
static DEFINE_MUTEX(dp_mutex);
+/* We limit the number of times that we pass into dp_process_received_packet()
+ * to avoid blowing out the stack in the event that we have a loop. */
+struct loop_counter {
+ int count; /* Count. */
+ bool looping; /* Loop detected? */
+};
+
+#define DP_MAX_LOOPS 5
+
+/* We use a separate counter for each CPU for both interrupt and non-interrupt
+ * context in order to keep the limit deterministic for a given packet. */
+struct percpu_loop_counters {
+ struct loop_counter counters[2];
+};
+
+static DEFINE_PER_CPU(struct percpu_loop_counters, dp_loop_counters);
+
static int new_dp_port(struct datapath *, struct odp_port *, int port_no);
/* Must be called with rcu_read_lock or dp_mutex. */
return err;
}
+static void suppress_loop(struct datapath *dp, struct sw_flow_actions *actions)
+{
+ if (net_ratelimit())
+ pr_warn("%s: flow looped %d times, dropping\n",
+ dp_name(dp), DP_MAX_LOOPS);
+ actions->n_actions = 0;
+}
+
/* Must be called with rcu_read_lock. */
void dp_process_received_packet(struct dp_port *p, struct sk_buff *skb)
{
int stats_counter_off;
struct odp_flow_key key;
struct tbl_node *flow_node;
+ struct sw_flow *flow;
+ struct sw_flow_actions *acts;
+ struct loop_counter *loop;
+ int error;
OVS_CB(skb)->dp_port = p;
- if (flow_extract(skb, p ? p->port_no : ODPP_NONE, &key)) {
- if (dp->drop_frags) {
- kfree_skb(skb);
- stats_counter_off = offsetof(struct dp_stats_percpu, n_frags);
- goto out;
- }
+ /* Extract flow from 'skb' into 'key'. */
+ error = flow_extract(skb, p ? p->port_no : ODPP_NONE, &key);
+ if (unlikely(error)) {
+ kfree_skb(skb);
+ return;
+ }
+
+ if (OVS_CB(skb)->is_frag && dp->drop_frags) {
+ kfree_skb(skb);
+ stats_counter_off = offsetof(struct dp_stats_percpu, n_frags);
+ goto out;
}
+ /* Look up flow. */
flow_node = tbl_lookup(rcu_dereference(dp->table), &key, flow_hash(&key), flow_cmp);
- if (flow_node) {
- struct sw_flow *flow = flow_cast(flow_node);
- struct sw_flow_actions *acts = rcu_dereference(flow->sf_acts);
- flow_used(flow, skb);
- execute_actions(dp, skb, &key, acts->actions, acts->n_actions,
- GFP_ATOMIC);
- stats_counter_off = offsetof(struct dp_stats_percpu, n_hit);
- } else {
- stats_counter_off = offsetof(struct dp_stats_percpu, n_missed);
+ if (unlikely(!flow_node)) {
dp_output_control(dp, skb, _ODPL_MISS_NR, OVS_CB(skb)->tun_id);
+ stats_counter_off = offsetof(struct dp_stats_percpu, n_missed);
+ goto out;
+ }
+
+ flow = flow_cast(flow_node);
+ flow_used(flow, skb);
+
+ acts = rcu_dereference(flow->sf_acts);
+
+ /* Check whether we've looped too much. */
+ loop = &get_cpu_var(dp_loop_counters).counters[!!in_interrupt()];
+ if (unlikely(++loop->count > DP_MAX_LOOPS))
+ loop->looping = true;
+ if (unlikely(loop->looping)) {
+ suppress_loop(dp, acts);
+ goto out_loop;
}
+ /* Execute actions. */
+ execute_actions(dp, skb, &key, acts->actions, acts->n_actions, GFP_ATOMIC);
+ stats_counter_off = offsetof(struct dp_stats_percpu, n_hit);
+
+ /* Check whether sub-actions looped too much. */
+ if (unlikely(loop->looping))
+ suppress_loop(dp, acts);
+
+out_loop:
+ /* Decrement loop counter. */
+ if (!--loop->count)
+ loop->looping = false;
+ put_cpu_var(dp_loop_counters);
+
out:
+ /* Update datapath statistics. */
local_bh_disable();
stats = per_cpu_ptr(dp->stats_percpu, smp_processor_id());
+
+ write_seqcount_begin(&stats->seqlock);
(*(u64 *)((u8 *)stats + stats_counter_off))++;
+ write_seqcount_end(&stats->seqlock);
+
local_bh_enable();
}
break;
default:
if (net_ratelimit())
- printk(KERN_ERR "Attempting to checksum a non-"
- "TCP/UDP packet, dropping a protocol"
- " %d packet", iph->protocol);
+ pr_err("Attempting to checksum a non-TCP/UDP packet, "
+ "dropping a protocol %d packet",
+ iph->protocol);
goto out;
}
break;
#endif
default:
- printk(KERN_ERR "openvswitch: unknown checksum type %d\n",
- skb->ip_summed);
+ pr_err("unknown checksum type %d\n", skb->ip_summed);
/* None seems the safest... */
OVS_CB(skb)->ip_summed = OVS_CSUM_NONE;
- }
+ }
#if defined(CONFIG_XEN) && defined(HAVE_PROTO_DATA_VALID)
/* Xen has a special way of representing CHECKSUM_PARTIAL on older
err:
local_bh_disable();
stats = per_cpu_ptr(dp->stats_percpu, smp_processor_id());
+
+ write_seqcount_begin(&stats->seqlock);
stats->n_lost++;
+ write_seqcount_end(&stats->seqlock);
+
local_bh_enable();
return err;
stats->n_packets = flow->packet_count;
stats->n_bytes = flow->byte_count;
- stats->ip_tos = flow->ip_tos;
+ stats->reserved = 0;
stats->tcp_flags = flow->tcp_flags;
stats->error = 0;
}
{
flow->used = 0;
flow->tcp_flags = 0;
- flow->ip_tos = 0;
flow->packet_count = 0;
flow->byte_count = 0;
}
else
skb->protocol = htons(ETH_P_802_2);
- flow_extract(skb, execute->in_port, &key);
+ err = flow_extract(skb, execute->in_port, &key);
+ if (err)
+ goto error_free_skb;
rcu_read_lock();
err = execute_actions(dp, skb, &key, actions->actions,
stats.max_groups = DP_MAX_GROUPS;
stats.n_frags = stats.n_hit = stats.n_missed = stats.n_lost = 0;
for_each_possible_cpu(i) {
- const struct dp_stats_percpu *s;
- s = per_cpu_ptr(dp->stats_percpu, i);
- stats.n_frags += s->n_frags;
- stats.n_hit += s->n_hit;
- stats.n_missed += s->n_missed;
- stats.n_lost += s->n_lost;
+ const struct dp_stats_percpu *percpu_stats;
+ struct dp_stats_percpu local_stats;
+ unsigned seqcount;
+
+ percpu_stats = per_cpu_ptr(dp->stats_percpu, i);
+
+ do {
+ seqcount = read_seqcount_begin(&percpu_stats->seqlock);
+ local_stats = *percpu_stats;
+ } while (read_seqcount_retry(&percpu_stats->seqlock, seqcount));
+
+ stats.n_frags += local_stats.n_frags;
+ stats.n_hit += local_stats.n_hit;
+ stats.n_missed += local_stats.n_missed;
+ stats.n_lost += local_stats.n_lost;
}
stats.max_miss_queue = DP_MAX_QUEUE_LEN;
stats.max_action_queue = DP_MAX_QUEUE_LEN;
}
success:
copy_bytes = tot_copy_bytes = min_t(size_t, skb->len, nbytes);
-
+
retval = 0;
if (skb->ip_summed == CHECKSUM_PARTIAL) {
if (copy_bytes == skb->len) {
git://git.onelab.eu / sliver-openvswitch.git / blobdiff