Function rte_ip_frag_sweep_table() enables callers to
incrementally sweep IP frament tables for incomplete, expired fragments.
rte_ip_frag_sweep_table() is needed to identify
never-to-be-completed fragments during DDoS attacks.
Signed-off-by: Qiaobin Fu <qiaob...@bu.edu>
Reviewed-by: Cody Doucette <douce...@bu.edu>
Reviewed-by: Michel Machado <mic...@digirati.com.br>
---
lib/librte_ip_frag/ip_frag_common.h | 18 +++++++++++++++++
lib/librte_ip_frag/ip_frag_internal.c | 18 -----------------
lib/librte_ip_frag/rte_ip_frag.h | 17 ++++++++++++++++
lib/librte_ip_frag/rte_ip_frag_common.c | 26 +++++++++++++++++++++++++
4 files changed, 61 insertions(+), 18 deletions(-)
diff --git a/lib/librte_ip_frag/ip_frag_common.h
b/lib/librte_ip_frag/ip_frag_common.h
index 197acf8d8..ef869182d 100644
--- a/lib/librte_ip_frag/ip_frag_common.h
+++ b/lib/librte_ip_frag/ip_frag_common.h
@@ -25,6 +25,12 @@
#define IPv6_KEY_BYTES_FMT \
"%08" PRIx64 "%08" PRIx64 "%08" PRIx64 "%08" PRIx64
+#ifdef RTE_LIBRTE_IP_FRAG_TBL_STAT
+#define IP_FRAG_TBL_STAT_UPDATE(s, f, v) ((s)->f += (v))
+#else
+#define IP_FRAG_TBL_STAT_UPDATE(s, f, v) do {} while (0)
+#endif /* IP_FRAG_TBL_STAT */
+
/* internal functions declarations */
struct rte_mbuf * ip_frag_process(struct ip_frag_pkt *fp,
struct rte_ip_frag_death_row *dr, struct rte_mbuf *mb,
@@ -149,4 +155,16 @@ ip_frag_reset(struct ip_frag_pkt *fp, uint64_t tms)
fp->frags[IP_FIRST_FRAG_IDX] = zero_frag;
}
+/* frag table helper functions */
+static inline void
+ip_frag_tbl_del(struct rte_ip_frag_tbl *tbl, struct rte_ip_frag_death_row *dr,
+ struct ip_frag_pkt *fp)
+{
+ ip_frag_free(fp, dr);
+ ip_frag_key_invalidate(&fp->key);
+ TAILQ_REMOVE(&tbl->lru, fp, lru);
+ tbl->use_entries--;
+ IP_FRAG_TBL_STAT_UPDATE(&tbl->stat, del_num, 1);
+}
+
#endif /* _IP_FRAG_COMMON_H_ */
diff --git a/lib/librte_ip_frag/ip_frag_internal.c
b/lib/librte_ip_frag/ip_frag_internal.c
index 2560c7713..97470a872 100644
--- a/lib/librte_ip_frag/ip_frag_internal.c
+++ b/lib/librte_ip_frag/ip_frag_internal.c
@@ -14,24 +14,6 @@
#define IP_FRAG_TBL_POS(tbl, sig) \
((tbl)->pkt + ((sig) & (tbl)->entry_mask))
-#ifdef RTE_LIBRTE_IP_FRAG_TBL_STAT
-#define IP_FRAG_TBL_STAT_UPDATE(s, f, v) ((s)->f += (v))
-#else
-#define IP_FRAG_TBL_STAT_UPDATE(s, f, v) do {} while (0)
-#endif /* IP_FRAG_TBL_STAT */
-
-/* local frag table helper functions */
-static inline void
-ip_frag_tbl_del(struct rte_ip_frag_tbl *tbl, struct rte_ip_frag_death_row *dr,
- struct ip_frag_pkt *fp)
-{
- ip_frag_free(fp, dr);
- ip_frag_key_invalidate(&fp->key);
- TAILQ_REMOVE(&tbl->lru, fp, lru);
- tbl->use_entries--;
- IP_FRAG_TBL_STAT_UPDATE(&tbl->stat, del_num, 1);
-}
-
static inline void
ip_frag_tbl_add(struct rte_ip_frag_tbl *tbl, struct ip_frag_pkt *fp,
const struct ip_frag_key *key, uint64_t tms)
diff --git a/lib/librte_ip_frag/rte_ip_frag.h b/lib/librte_ip_frag/rte_ip_frag.h
index b3f3f78df..79443096c 100644
--- a/lib/librte_ip_frag/rte_ip_frag.h
+++ b/lib/librte_ip_frag/rte_ip_frag.h
@@ -146,6 +146,23 @@ struct rte_ip_frag_tbl * rte_ip_frag_table_create(uint32_t
bucket_num,
uint32_t bucket_entries, uint32_t max_entries,
uint64_t max_cycles, int socket_id);
+/**
+ * Sweep the IP fragmentation table for expired segments.
+ *
+ * @param tbl
+ * Fragmentation table to sweep.
+ * @param dr
+ * Death row to free buffers to
+ * @param next
+ * Pointer to the bucket iterator.
+ * Should be 0 to start sweeping the fragmentation table.
+ * Bucket iterator is incremented after each call of this function.
+ * @return
+ * 0 if successful. -EINVAL if the parameters are invalid.
+ */
+int rte_ip_frag_sweep_table(struct rte_ip_frag_tbl *tbl,
+ struct rte_ip_frag_death_row *dr, uint32_t *next);
+
/**
* Free allocated IP fragmentation table.
*
diff --git a/lib/librte_ip_frag/rte_ip_frag_common.c
b/lib/librte_ip_frag/rte_ip_frag_common.c
index 659a17951..53325ddae 100644
--- a/lib/librte_ip_frag/rte_ip_frag_common.c
+++ b/lib/librte_ip_frag/rte_ip_frag_common.c
@@ -7,6 +7,7 @@
#include <rte_memory.h>
#include <rte_log.h>
+#include <rte_cycles.h>
#include "ip_frag_common.h"
@@ -93,6 +94,31 @@ rte_ip_frag_table_destroy(struct rte_ip_frag_tbl *tbl)
rte_free(tbl);
}
+/* Sweep the IP fragmentation table. */
+int
+rte_ip_frag_sweep_table(struct rte_ip_frag_tbl *tbl,
+ struct rte_ip_frag_death_row *dr, uint32_t *next)
+{
+ uint32_t i;
+ uint64_t cur_tsc = rte_rdtsc();
+ struct ip_frag_pkt *pkt;
+
+ if (tbl == NULL || dr == NULL || next == NULL ||
+ (*next * tbl->bucket_entries >= tbl->nb_entries))
+ return -EINVAL;
+
+ pkt = tbl->pkt + *next * tbl->bucket_entries;
+ for (i = 0; i < tbl->bucket_entries; i++) {
+ if (tbl->max_cycles + pkt[i].start < cur_tsc)
+ ip_frag_tbl_del(tbl, dr, pkt + i);
+ }
+
+ *next = (*next + 1) * tbl->bucket_entries >= tbl->nb_entries ?
+ 0 : *next + 1;
+
+ return 0;
+}
+
/* dump frag table statistics to file */
void
rte_ip_frag_table_statistics_dump(FILE *f, const struct rte_ip_frag_tbl *tbl)
--
2.17.1
