--- /dev/null
+/*
+ * Copyright (c) 2019 Nicira, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+#include <ctype.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <netinet/ip6.h>
+#include <netinet/icmp6.h>
+#include <string.h>
+
+#include "coverage.h"
+#include "csum.h"
+#include "ipf.h"
+#include "latch.h"
+#include "openvswitch/hmap.h"
+#include "openvswitch/poll-loop.h"
+#include "openvswitch/vlog.h"
+#include "ovs-atomic.h"
+#include "packets.h"
+#include "util.h"
+
+VLOG_DEFINE_THIS_MODULE(ipf);
+COVERAGE_DEFINE(ipf_stuck_frag_list_purged);
+
+enum {
+ IPV4_PACKET_MAX_HDR_SIZE = 60,
+ IPV4_PACKET_MAX_SIZE = 65535,
+ IPV6_PACKET_MAX_DATA = 65535,
+};
+
+enum ipf_list_state {
+ IPF_LIST_STATE_UNUSED,
+ IPF_LIST_STATE_REASS_FAIL,
+ IPF_LIST_STATE_OTHER_SEEN,
+ IPF_LIST_STATE_FIRST_SEEN,
+ IPF_LIST_STATE_LAST_SEEN,
+ IPF_LIST_STATE_FIRST_LAST_SEEN,
+ IPF_LIST_STATE_COMPLETED,
+ IPF_LIST_STATE_NUM,
+};
+
+static char *ipf_state_name[IPF_LIST_STATE_NUM] =
+ {"unused", "reassemble fail", "other frag", "first frag", "last frag",
+ "first/last frag", "complete"};
+
+enum ipf_list_type {
+ IPF_FRAG_COMPLETED_LIST,
+ IPF_FRAG_EXPIRY_LIST,
+};
+
+enum {
+ IPF_INVALID_IDX = -1,
+ IPF_V4_FRAG_SIZE_LBOUND = 400,
+ IPF_V4_FRAG_SIZE_MIN_DEF = 1200,
+ IPF_V6_FRAG_SIZE_LBOUND = 400, /* Useful for testing. */
+ IPF_V6_FRAG_SIZE_MIN_DEF = 1280,
+ IPF_MAX_FRAGS_DEFAULT = 1000,
+ IPF_NFRAG_UBOUND = 5000,
+};
+
+enum ipf_counter_type {
+ IPF_NFRAGS_ACCEPTED,
+ IPF_NFRAGS_COMPL_SENT,
+ IPF_NFRAGS_EXPD_SENT,
+ IPF_NFRAGS_TOO_SMALL,
+ IPF_NFRAGS_OVERLAP,
+ IPF_NFRAGS_PURGED,
+ IPF_NFRAGS_NUM_CNTS,
+};
+
+union ipf_addr {
+ ovs_be32 ipv4;
+ struct in6_addr ipv6;
+};
+
+/* Represents a single fragment; part of a list of fragments. */
+struct ipf_frag {
+ struct dp_packet *pkt;
+ uint16_t start_data_byte;
+ uint16_t end_data_byte;
+ bool dnsteal; /* 'do not steal': if true, ipf should not free packet. */
+};
+
+/* The key for a collection of fragments potentially making up an unfragmented
+ * packet. */
+struct ipf_list_key {
+ /* ipf_list_key_hash() requires 'src_addr' and 'dst_addr' to be the first
+ * two members. */
+ union ipf_addr src_addr;
+ union ipf_addr dst_addr;
+ uint32_t recirc_id;
+ ovs_be32 ip_id; /* V6 is 32 bits. */
+ ovs_be16 dl_type;
+ uint16_t zone;
+ uint8_t nw_proto;
+};
+
+/* A collection of fragments potentially making up an unfragmented packet. */
+struct ipf_list {
+ struct hmap_node node; /* In struct ipf's 'frag_lists'. */
+ struct ovs_list list_node; /* In struct ipf's 'frag_exp_list' or
+ * 'frag_complete_list'. */
+ struct ipf_frag *frag_list; /* List of fragments for this list. */
+ struct ipf_list_key key; /* The key for the fragemnt list. */
+ struct dp_packet *reass_execute_ctx; /* Reassembled packet. */
+ long long expiration; /* In milliseconds. */
+ int last_sent_idx; /* Last sent fragment idx. */
+ int last_inuse_idx; /* Last inuse fragment idx. */
+ int size; /* Fragment list size. */
+ uint8_t state; /* Frag list state; see ipf_list_state. */
+};
+
+/* Represents a reassambled packet which typically is passed through
+ * conntrack. */
+struct reassembled_pkt {
+ struct ovs_list rp_list_node; /* In struct ipf's
+ * 'reassembled_pkt_list'. */
+ struct dp_packet *pkt;
+ struct ipf_list *list;
+};
+
+struct ipf {
+ /* The clean thread is used to clean up fragments in the 'ipf'
+ * module if packet batches are not longer be sent through its user. */
+ pthread_t ipf_clean_thread;
+ struct latch ipf_clean_thread_exit;
+
+ int max_v4_frag_list_size;
+
+ struct ovs_mutex ipf_lock; /* Protects all of the following. */
+ /* These contain 'struct ipf_list's. */
+ struct hmap frag_lists OVS_GUARDED;
+ struct ovs_list frag_exp_list OVS_GUARDED;
+ struct ovs_list frag_complete_list OVS_GUARDED;
+ /* Contains 'struct reassembled_pkt's. */
+ struct ovs_list reassembled_pkt_list OVS_GUARDED;
+
+ /* Used to allow disabling fragmentation reassembly. */
+ atomic_bool ifp_v4_enabled;
+ atomic_bool ifp_v6_enabled;
+
+ /* Will be clamped above 400 bytes; the value chosen should handle
+ * alg control packets of interest that use string encoding of mutable
+ * IP fields; meaning, the control packets should not be fragmented. */
+ atomic_uint min_v4_frag_size;
+ atomic_uint min_v6_frag_size;
+
+ /* Configurable maximum allowable fragments in process. */
+ atomic_uint nfrag_max;
+
+ /* Number of fragments in process. */
+ atomic_count nfrag;
+
+ atomic_uint64_t n4frag_cnt[IPF_NFRAGS_NUM_CNTS];
+ atomic_uint64_t n6frag_cnt[IPF_NFRAGS_NUM_CNTS];
+};
+
+static void
+ipf_print_reass_packet(const char *es, const void *pkt)
+{
+ static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(10, 10);
+ if (!VLOG_DROP_WARN(&rl)) {
+ struct ds ds = DS_EMPTY_INITIALIZER;
+ ds_put_hex_dump(&ds, pkt, 128, 0, false);
+ VLOG_WARN("%s\n%s", es, ds_cstr(&ds));
+ ds_destroy(&ds);
+ }
+}
+
+static void
+ipf_count(struct ipf *ipf, bool v6, enum ipf_counter_type cntr)
+{
+ atomic_count_inc64(v6 ? &ipf->n6frag_cnt[cntr] : &ipf->n4frag_cnt[cntr]);
+}
+
+static bool
+ipf_get_v4_enabled(struct ipf *ipf)
+{
+ bool ifp_v4_enabled_;
+ atomic_read_relaxed(&ipf->ifp_v4_enabled, &ifp_v4_enabled_);
+ return ifp_v4_enabled_;
+}
+
+static bool
+ipf_get_v6_enabled(struct ipf *ipf)
+{
+ bool ifp_v6_enabled_;
+ atomic_read_relaxed(&ipf->ifp_v6_enabled, &ifp_v6_enabled_);
+ return ifp_v6_enabled_;
+}
+
+static bool
+ipf_get_enabled(struct ipf *ipf)
+{
+ return ipf_get_v4_enabled(ipf) || ipf_get_v6_enabled(ipf);
+}
+
+static uint32_t
+ipf_addr_hash_add(uint32_t hash, const union ipf_addr *addr)
+{
+ BUILD_ASSERT_DECL(sizeof *addr % 4 == 0);
+ return hash_add_bytes32(hash, (const uint32_t *) addr, sizeof *addr);
+}
+
+/* Adds a list of fragments to the list tracking expiry of yet to be
+ * completed reassembled packets, hence subject to expirty. */
+static void
+ipf_expiry_list_add(struct ovs_list *frag_exp_list, struct ipf_list *ipf_list,
+ long long now)
+ /* OVS_REQUIRES(ipf->ipf_lock) */
+{
+ enum {
+ IPF_FRAG_LIST_TIMEOUT = 15000,
+ };
+
+ ipf_list->expiration = now + IPF_FRAG_LIST_TIMEOUT;
+ ovs_list_push_back(frag_exp_list, &ipf_list->list_node);
+}
+
+/* Adds a list of fragments to the list of completed packets, which will be
+ * subsequently transmitted. */
+static void
+ipf_completed_list_add(struct ovs_list *frag_complete_list,
+ struct ipf_list *ipf_list)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ ovs_list_push_back(frag_complete_list, &ipf_list->list_node);
+}
+
+/* Adds a reassmebled packet to the list of reassembled packets, awaiting some
+ * processing, such as being sent through conntrack. */
+static void
+ipf_reassembled_list_add(struct ovs_list *reassembled_pkt_list,
+ struct reassembled_pkt *rp)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ ovs_list_push_back(reassembled_pkt_list, &rp->rp_list_node);
+}
+
+/* Removed a frag list from tracking datastructures and frees list heap
+ * memory. */
+static void
+ipf_list_clean(struct hmap *frag_lists,
+ struct ipf_list *ipf_list)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ ovs_list_remove(&ipf_list->list_node);
+ hmap_remove(frag_lists, &ipf_list->node);
+ free(ipf_list->frag_list);
+ free(ipf_list);
+}
+
+/* Removed a frag list sitting on the expiry list from tracking
+ * datastructures and frees list heap memory. */
+static void
+ipf_expiry_list_clean(struct hmap *frag_lists,
+ struct ipf_list *ipf_list)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ ipf_list_clean(frag_lists, ipf_list);
+}
+
+/* Removed a frag list sitting on the completed list from tracking
+ * datastructures and frees list heap memory. */
+static void
+ipf_completed_list_clean(struct hmap *frag_lists,
+ struct ipf_list *ipf_list)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ ipf_list_clean(frag_lists, ipf_list);
+}
+
+static void
+ipf_expiry_list_remove(struct ipf_list *ipf_list)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ ovs_list_remove(&ipf_list->list_node);
+}
+
+static void
+ipf_reassembled_list_remove(struct reassembled_pkt *rp)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ ovs_list_remove(&rp->rp_list_node);
+}
+
+/* Symmetric */
+static uint32_t
+ipf_list_key_hash(const struct ipf_list_key *key, uint32_t basis)
+{
+ uint32_t hsrc, hdst, hash;
+ hsrc = hdst = basis;
+ hsrc = ipf_addr_hash_add(hsrc, &key->src_addr);
+ hdst = ipf_addr_hash_add(hdst, &key->dst_addr);
+ hash = hsrc ^ hdst;
+
+ /* Hash the rest of the key. */
+ return hash_words((uint32_t *) (&key->dst_addr + 1),
+ (uint32_t *) (key + 1) -
+ (uint32_t *) (&key->dst_addr + 1),
+ hash);
+}
+
+static bool
+ipf_is_first_v4_frag(const struct dp_packet *pkt)
+{
+ const struct ip_header *l3 = dp_packet_l3(pkt);
+ if (!(l3->ip_frag_off & htons(IP_FRAG_OFF_MASK)) &&
+ l3->ip_frag_off & htons(IP_MORE_FRAGMENTS)) {
+ return true;
+ }
+ return false;
+}
+
+static bool
+ipf_is_last_v4_frag(const struct dp_packet *pkt)
+{
+ const struct ip_header *l3 = dp_packet_l3(pkt);
+ if (l3->ip_frag_off & htons(IP_FRAG_OFF_MASK) &&
+ !(l3->ip_frag_off & htons(IP_MORE_FRAGMENTS))) {
+ return true;
+ }
+ return false;
+}
+
+static bool
+ipf_is_v6_frag(ovs_be16 ip6f_offlg)
+{
+ if (ip6f_offlg & (IP6F_OFF_MASK | IP6F_MORE_FRAG)) {
+ return true;
+ }
+ return false;
+}
+
+static bool
+ipf_is_first_v6_frag(ovs_be16 ip6f_offlg)
+{
+ if (!(ip6f_offlg & IP6F_OFF_MASK) &&
+ ip6f_offlg & IP6F_MORE_FRAG) {
+ return true;
+ }
+ return false;
+}
+
+static bool
+ipf_is_last_v6_frag(ovs_be16 ip6f_offlg)
+{
+ if ((ip6f_offlg & IP6F_OFF_MASK) &&
+ !(ip6f_offlg & IP6F_MORE_FRAG)) {
+ return true;
+ }
+ return false;
+}
+
+/* Checks for a completed packet collection of fragments. */
+static bool
+ipf_list_complete(const struct ipf_list *ipf_list)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ for (int i = 1; i <= ipf_list->last_inuse_idx; i++) {
+ if (ipf_list->frag_list[i - 1].end_data_byte + 1
+ != ipf_list->frag_list[i].start_data_byte) {
+ return false;
+ }
+ }
+ return true;
+}
+
+/* Runs O(n) for a sorted or almost sorted list. */
+static void
+ipf_sort(struct ipf_frag *frag_list, size_t last_idx)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ for (int li = 1; li <= last_idx; li++) {
+ struct ipf_frag ipf_frag = frag_list[li];
+ int ci = li - 1;
+ while (ci >= 0 &&
+ frag_list[ci].start_data_byte > ipf_frag.start_data_byte) {
+ frag_list[ci + 1] = frag_list[ci];
+ ci--;
+ }
+ frag_list[ci + 1] = ipf_frag;
+ }
+}
+
+/* Called on a sorted complete list of v4 fragments to reassemble them into
+ * a single packet that can be processed, such as passing through conntrack.
+ */
+static struct dp_packet *
+ipf_reassemble_v4_frags(struct ipf_list *ipf_list)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ struct ipf_frag *frag_list = ipf_list->frag_list;
+ struct dp_packet *pkt = dp_packet_clone(frag_list[0].pkt);
+ struct ip_header *l3 = dp_packet_l3(pkt);
+ int len = ntohs(l3->ip_tot_len);
+
+ int rest_len = frag_list[ipf_list->last_inuse_idx].end_data_byte -
+ frag_list[1].start_data_byte + 1;
+
+ if (len + rest_len > IPV4_PACKET_MAX_SIZE) {
+ ipf_print_reass_packet(
+ "Unsupported big reassembled v4 packet; v4 hdr:", l3);
+ dp_packet_delete(pkt);
+ return NULL;
+ }
+
+ dp_packet_prealloc_tailroom(pkt, len + rest_len);
+
+ for (int i = 1; i <= ipf_list->last_inuse_idx; i++) {
+ size_t add_len = frag_list[i].end_data_byte -
+ frag_list[i].start_data_byte + 1;
+ len += add_len;
+ const char *l4 = dp_packet_l4(frag_list[i].pkt);
+ dp_packet_put(pkt, l4, add_len);
+ }
+ l3 = dp_packet_l3(pkt);
+ ovs_be16 new_ip_frag_off = l3->ip_frag_off & ~htons(IP_MORE_FRAGMENTS);
+ l3->ip_csum = recalc_csum16(l3->ip_csum, l3->ip_frag_off,
+ new_ip_frag_off);
+ l3->ip_csum = recalc_csum16(l3->ip_csum, l3->ip_tot_len, htons(len));
+ l3->ip_tot_len = htons(len);
+ l3->ip_frag_off = new_ip_frag_off;
+ dp_packet_set_l2_pad_size(pkt, 0);
+
+ return pkt;
+}
+
+/* Called on a sorted complete list of v6 fragments to reassemble them into
+ * a single packet that can be processed, such as passing through conntrack.
+ */
+static struct dp_packet *
+ipf_reassemble_v6_frags(struct ipf_list *ipf_list)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ struct ipf_frag *frag_list = ipf_list->frag_list;
+ struct dp_packet *pkt = dp_packet_clone(frag_list[0].pkt);
+ struct ovs_16aligned_ip6_hdr *l3 = dp_packet_l3(pkt);
+ int pl = ntohs(l3->ip6_plen) - sizeof(struct ovs_16aligned_ip6_frag);
+
+ int rest_len = frag_list[ipf_list->last_inuse_idx].end_data_byte -
+ frag_list[1].start_data_byte + 1;
+
+ if (pl + rest_len > IPV4_PACKET_MAX_SIZE) {
+ ipf_print_reass_packet(
+ "Unsupported big reassembled v6 packet; v6 hdr:", l3);
+ dp_packet_delete(pkt);
+ return NULL;
+ }
+
+ dp_packet_prealloc_tailroom(pkt, pl + rest_len);
+
+ for (int i = 1; i <= ipf_list->last_inuse_idx; i++) {
+ size_t add_len = frag_list[i].end_data_byte -
+ frag_list[i].start_data_byte + 1;
+ pl += add_len;
+ const char *l4 = dp_packet_l4(frag_list[i].pkt);
+ dp_packet_put(pkt, l4, add_len);
+ }
+
+ l3 = dp_packet_l3(pkt);
+
+ uint8_t nw_proto = l3->ip6_nxt;
+ uint8_t nw_frag = 0;
+ const void *data = l3 + 1;
+ size_t datasize = pl;
+
+ const struct ovs_16aligned_ip6_frag *frag_hdr = NULL;
+ if (!parse_ipv6_ext_hdrs(&data, &datasize, &nw_proto, &nw_frag, &frag_hdr)
+ || !nw_frag || !frag_hdr) {
+
+ ipf_print_reass_packet("Unparsed reassembled v6 packet; v6 hdr:", l3);
+ dp_packet_delete(pkt);
+ return NULL;
+ }
+
+ struct ovs_16aligned_ip6_frag *fh =
+ CONST_CAST(struct ovs_16aligned_ip6_frag *, frag_hdr);
+ fh->ip6f_offlg = 0;
+ l3->ip6_plen = htons(pl);
+ l3->ip6_ctlun.ip6_un1.ip6_un1_nxt = nw_proto;
+ dp_packet_set_l2_pad_size(pkt, 0);
+ return pkt;
+}
+
+/* Called when a frag list state transitions to another state. This is
+ * triggered by new fragment for the list being received.*/
+static void
+ipf_list_state_transition(struct ipf *ipf, struct ipf_list *ipf_list,
+ bool ff, bool lf, bool v6)
+ OVS_REQUIRES(ipf->ipf_lock)
+{
+ enum ipf_list_state curr_state = ipf_list->state;
+ enum ipf_list_state next_state;
+ switch (curr_state) {
+ case IPF_LIST_STATE_UNUSED:
+ case IPF_LIST_STATE_OTHER_SEEN:
+ if (ff) {
+ next_state = IPF_LIST_STATE_FIRST_SEEN;
+ } else if (lf) {
+ next_state = IPF_LIST_STATE_LAST_SEEN;
+ } else {
+ next_state = IPF_LIST_STATE_OTHER_SEEN;
+ }
+ break;
+ case IPF_LIST_STATE_FIRST_SEEN:
+ if (ff) {
+ next_state = IPF_LIST_STATE_FIRST_SEEN;
+ } else if (lf) {
+ next_state = IPF_LIST_STATE_FIRST_LAST_SEEN;
+ } else {
+ next_state = IPF_LIST_STATE_FIRST_SEEN;
+ }
+ break;
+ case IPF_LIST_STATE_LAST_SEEN:
+ if (ff) {
+ next_state = IPF_LIST_STATE_FIRST_LAST_SEEN;
+ } else if (lf) {
+ next_state = IPF_LIST_STATE_LAST_SEEN;
+ } else {
+ next_state = IPF_LIST_STATE_LAST_SEEN;
+ }
+ break;
+ case IPF_LIST_STATE_FIRST_LAST_SEEN:
+ next_state = IPF_LIST_STATE_FIRST_LAST_SEEN;
+ break;
+ case IPF_LIST_STATE_COMPLETED:
+ case IPF_LIST_STATE_REASS_FAIL:
+ case IPF_LIST_STATE_NUM:
+ default:
+ OVS_NOT_REACHED();
+ }
+
+ if (next_state == IPF_LIST_STATE_FIRST_LAST_SEEN) {
+ ipf_sort(ipf_list->frag_list, ipf_list->last_inuse_idx);
+ if (ipf_list_complete(ipf_list)) {
+ struct dp_packet *reass_pkt = v6
+ ? ipf_reassemble_v6_frags(ipf_list)
+ : ipf_reassemble_v4_frags(ipf_list);
+ if (reass_pkt) {
+ struct reassembled_pkt *rp = xzalloc(sizeof *rp);
+ rp->pkt = reass_pkt;
+ rp->list = ipf_list;
+ ipf_reassembled_list_add(&ipf->reassembled_pkt_list, rp);
+ ipf_expiry_list_remove(ipf_list);
+ next_state = IPF_LIST_STATE_COMPLETED;
+ } else {
+ next_state = IPF_LIST_STATE_REASS_FAIL;
+ }
+ }
+ }
+ ipf_list->state = next_state;
+}
+
+/* Some sanity checks are redundant, but prudent, in case code paths for
+ * fragments change in future. The processing cost for fragments is not
+ * important. */
+static bool
+ipf_is_valid_v4_frag(struct ipf *ipf, struct dp_packet *pkt)
+{
+ if (OVS_UNLIKELY(dp_packet_ip_checksum_bad(pkt))) {
+ goto invalid_pkt;
+ }
+
+ const struct eth_header *l2 = dp_packet_eth(pkt);
+ const struct ip_header *l3 = dp_packet_l3(pkt);
+
+ if (OVS_UNLIKELY(!l2 || !l3)) {
+ goto invalid_pkt;
+ }
+
+ size_t l3_size = dp_packet_l3_size(pkt);
+ if (OVS_UNLIKELY(l3_size < IP_HEADER_LEN)) {
+ goto invalid_pkt;
+ }
+
+ if (!IP_IS_FRAGMENT(l3->ip_frag_off)) {
+ return false;
+ }
+
+ uint16_t ip_tot_len = ntohs(l3->ip_tot_len);
+ if (OVS_UNLIKELY(ip_tot_len != l3_size)) {
+ goto invalid_pkt;
+ }
+
+ size_t ip_hdr_len = IP_IHL(l3->ip_ihl_ver) * 4;
+ if (OVS_UNLIKELY(ip_hdr_len < IP_HEADER_LEN)) {
+ goto invalid_pkt;
+ }
+ if (OVS_UNLIKELY(l3_size < ip_hdr_len)) {
+ goto invalid_pkt;
+ }
+
+ if (OVS_UNLIKELY(!dp_packet_ip_checksum_valid(pkt)
+ && csum(l3, ip_hdr_len) != 0)) {
+ goto invalid_pkt;
+ }
+
+ uint32_t min_v4_frag_size_;
+ atomic_read_relaxed(&ipf->min_v4_frag_size, &min_v4_frag_size_);
+ bool lf = ipf_is_last_v4_frag(pkt);
+ if (OVS_UNLIKELY(!lf && dp_packet_size(pkt) < min_v4_frag_size_)) {
+ ipf_count(ipf, false, IPF_NFRAGS_TOO_SMALL);
+ goto invalid_pkt;
+ }
+ return true;
+
+invalid_pkt:
+ pkt->md.ct_state = CS_INVALID;
+ return false;
+}
+
+static bool
+ipf_v4_key_extract(struct dp_packet *pkt, ovs_be16 dl_type, uint16_t zone,
+ struct ipf_list_key *key, uint16_t *start_data_byte,
+ uint16_t *end_data_byte, bool *ff, bool *lf)
+{
+ const struct ip_header *l3 = dp_packet_l3(pkt);
+ uint16_t ip_tot_len = ntohs(l3->ip_tot_len);
+ size_t ip_hdr_len = IP_IHL(l3->ip_ihl_ver) * 4;
+
+ *start_data_byte = ntohs(l3->ip_frag_off & htons(IP_FRAG_OFF_MASK)) * 8;
+ *end_data_byte = *start_data_byte + ip_tot_len - ip_hdr_len - 1;
+ *ff = ipf_is_first_v4_frag(pkt);
+ *lf = ipf_is_last_v4_frag(pkt);
+ memset(key, 0, sizeof *key);
+ key->ip_id = be16_to_be32(l3->ip_id);
+ key->dl_type = dl_type;
+ key->src_addr.ipv4 = get_16aligned_be32(&l3->ip_src);
+ key->dst_addr.ipv4 = get_16aligned_be32(&l3->ip_dst);
+ key->nw_proto = l3->ip_proto;
+ key->zone = zone;
+ key->recirc_id = pkt->md.recirc_id;
+ return true;
+}
+
+/* Some sanity checks are redundant, but prudent, in case code paths for
+ * fragments change in future. The processing cost for fragments is not
+ * important. */
+static bool
+ipf_is_valid_v6_frag(struct ipf *ipf, struct dp_packet *pkt)
+{
+ const struct eth_header *l2 = dp_packet_eth(pkt);
+ const struct ovs_16aligned_ip6_hdr *l3 = dp_packet_l3(pkt);
+ const char *l4 = dp_packet_l4(pkt);
+
+ if (OVS_UNLIKELY(!l2 || !l3 || !l4)) {
+ goto invalid_pkt;
+ }
+
+ size_t l3_size = dp_packet_l3_size(pkt);
+ size_t l3_hdr_size = sizeof *l3;
+
+ if (OVS_UNLIKELY(l3_size < l3_hdr_size)) {
+ goto invalid_pkt;
+ }
+
+ uint8_t nw_frag = 0;
+ uint8_t nw_proto = l3->ip6_nxt;
+ const void *data = l3 + 1;
+ size_t datasize = l3_size - l3_hdr_size;
+ const struct ovs_16aligned_ip6_frag *frag_hdr = NULL;
+ if (!parse_ipv6_ext_hdrs(&data, &datasize, &nw_proto, &nw_frag,
+ &frag_hdr) || !nw_frag || !frag_hdr) {
+ return false;
+ }
+
+ int pl = ntohs(l3->ip6_plen);
+ if (OVS_UNLIKELY(pl + l3_hdr_size != l3_size)) {
+ goto invalid_pkt;
+ }
+
+ ovs_be16 ip6f_offlg = frag_hdr->ip6f_offlg;
+ if (OVS_UNLIKELY(!ipf_is_v6_frag(ip6f_offlg))) {
+ return false;
+ }
+
+ uint32_t min_v6_frag_size_;
+ atomic_read_relaxed(&ipf->min_v6_frag_size, &min_v6_frag_size_);
+ bool lf = ipf_is_last_v6_frag(ip6f_offlg);
+
+ if (OVS_UNLIKELY(!lf && dp_packet_size(pkt) < min_v6_frag_size_)) {
+ ipf_count(ipf, true, IPF_NFRAGS_TOO_SMALL);
+ goto invalid_pkt;
+ }
+
+ return true;
+
+invalid_pkt:
+ pkt->md.ct_state = CS_INVALID;
+ return false;
+
+}
+
+static void
+ipf_v6_key_extract(struct dp_packet *pkt, ovs_be16 dl_type, uint16_t zone,
+ struct ipf_list_key *key, uint16_t *start_data_byte,
+ uint16_t *end_data_byte, bool *ff, bool *lf)
+{
+ const struct ovs_16aligned_ip6_hdr *l3 = dp_packet_l3(pkt);
+ const char *l4 = dp_packet_l4(pkt);
+ const char *tail = dp_packet_tail(pkt);
+ uint8_t pad = dp_packet_l2_pad_size(pkt);
+ size_t l3_size = tail - (char *)l3 - pad;
+ size_t l4_size = tail - (char *)l4 - pad;
+ size_t l3_hdr_size = sizeof *l3;
+ uint8_t nw_frag = 0;
+ uint8_t nw_proto = l3->ip6_nxt;
+ const void *data = l3 + 1;
+ size_t datasize = l3_size - l3_hdr_size;
+ const struct ovs_16aligned_ip6_frag *frag_hdr = NULL;
+
+ parse_ipv6_ext_hdrs(&data, &datasize, &nw_proto, &nw_frag, &frag_hdr);
+ ovs_assert(nw_frag && frag_hdr);
+ ovs_be16 ip6f_offlg = frag_hdr->ip6f_offlg;
+ *start_data_byte = ntohs(ip6f_offlg & IP6F_OFF_MASK) +
+ sizeof (struct ovs_16aligned_ip6_frag);
+ *end_data_byte = *start_data_byte + l4_size - 1;
+ *ff = ipf_is_first_v6_frag(ip6f_offlg);
+ *lf = ipf_is_last_v6_frag(ip6f_offlg);
+ memset(key, 0, sizeof *key);
+ key->ip_id = get_16aligned_be32(&frag_hdr->ip6f_ident);
+ key->dl_type = dl_type;
+ memcpy(&key->src_addr.ipv6, &l3->ip6_src, sizeof key->src_addr.ipv6);
+ /* We are not supporting parsing of the routing header to use as the
+ * dst address part of the key. */
+ memcpy(&key->dst_addr.ipv6, &l3->ip6_dst, sizeof key->dst_addr.ipv6);
+ key->nw_proto = 0; /* Not used for key for V6. */
+ key->zone = zone;
+ key->recirc_id = pkt->md.recirc_id;
+}
+
+static bool
+ipf_list_key_eq(const struct ipf_list_key *key1,
+ const struct ipf_list_key *key2)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ if (!memcmp(&key1->src_addr, &key2->src_addr, sizeof key1->src_addr) &&
+ !memcmp(&key1->dst_addr, &key2->dst_addr, sizeof key1->dst_addr) &&
+ key1->dl_type == key2->dl_type &&
+ key1->ip_id == key2->ip_id &&
+ key1->zone == key2->zone &&
+ key1->nw_proto == key2->nw_proto &&
+ key1->recirc_id == key2->recirc_id) {
+ return true;
+ }
+ return false;
+}
+
+static struct ipf_list *
+ipf_list_key_lookup(struct ipf *ipf, const struct ipf_list_key *key,
+ uint32_t hash)
+ /* OVS_REQUIRES(ipf->ipf_lock) */
+{
+ struct ipf_list *ipf_list;
+ HMAP_FOR_EACH_WITH_HASH (ipf_list, node, hash, &ipf->frag_lists) {
+ if (ipf_list_key_eq(&ipf_list->key, key)) {
+ return ipf_list;
+ }
+ }
+ return NULL;
+}
+
+static bool
+ipf_is_frag_duped(const struct ipf_frag *frag_list, int last_inuse_idx,
+ size_t start_data_byte, size_t end_data_byte)
+ /* OVS_REQUIRES(ipf_lock) */
+{
+ for (int i = 0; i <= last_inuse_idx; i++) {
+ if ((start_data_byte >= frag_list[i].start_data_byte &&
+ start_data_byte <= frag_list[i].end_data_byte) ||
+ (end_data_byte >= frag_list[i].start_data_byte &&
+ end_data_byte <= frag_list[i].end_data_byte)) {
+ return true;
+ }
+ }
+ return false;
+}
+
+/* Adds a fragment to a list of fragments, if the fragment is not a
+ * duplicate. If the fragment is a duplicate, that fragment is marked
+ * invalid to avoid the work that conntrack would do to mark the fragment
+ * as invalid, which it will in all cases. */
+static bool
+ipf_process_frag(struct ipf *ipf, struct ipf_list *ipf_list,
+ struct dp_packet *pkt, uint16_t start_data_byte,
+ uint16_t end_data_byte, bool ff, bool lf, bool v6,
+ bool dnsteal)
+ OVS_REQUIRES(ipf->ipf_lock)
+{
+ bool duped_frag = ipf_is_frag_duped(ipf_list->frag_list,
+ ipf_list->last_inuse_idx, start_data_byte, end_data_byte);
+ int last_inuse_idx = ipf_list->last_inuse_idx;
+
+ if (!duped_frag) {
+ if (last_inuse_idx < ipf_list->size - 1) {
+ /* In the case of dpdk, it would be unfortunate if we had
+ * to create a clone fragment outside the dpdk mp due to the
+ * mempool size being too limited. We will otherwise need to
+ * recommend not setting the mempool number of buffers too low
+ * and also clamp the number of fragments. */
+ struct ipf_frag *frag = &ipf_list->frag_list[last_inuse_idx + 1];
+ frag->pkt = pkt;
+ frag->start_data_byte = start_data_byte;
+ frag->end_data_byte = end_data_byte;
+ frag->dnsteal = dnsteal;
+ ipf_list->last_inuse_idx++;
+ atomic_count_inc(&ipf->nfrag);
+ ipf_count(ipf, v6, IPF_NFRAGS_ACCEPTED);
+ ipf_list_state_transition(ipf, ipf_list, ff, lf, v6);
+ } else {
+ OVS_NOT_REACHED();
+ }
+ } else {
+ ipf_count(ipf, v6, IPF_NFRAGS_OVERLAP);
+ pkt->md.ct_state = CS_INVALID;
+ return false;
+ }
+ return true;
+}
+
+static void
+ipf_list_init(struct ipf_list *ipf_list, struct ipf_list_key *key,
+ int max_frag_list_size)
+{
+ ipf_list->key = *key;
+ ipf_list->last_inuse_idx = IPF_INVALID_IDX;
+ ipf_list->last_sent_idx = IPF_INVALID_IDX;
+ ipf_list->reass_execute_ctx = NULL;
+ ipf_list->state = IPF_LIST_STATE_UNUSED;
+ ipf_list->size = max_frag_list_size;
+ ipf_list->frag_list
+ = xzalloc(ipf_list->size * sizeof *ipf_list->frag_list);
+}
+
+/* Generates a fragment list key from a well formed fragment and either starts
+ * a new fragment list or increases the size of the existing fragment list,
+ * while checking if the maximum supported fragements are supported or the
+ * list size is impossibly big. Calls 'ipf_process_frag()' to add a fragment
+ * to a list of fragemnts. */
+static bool
+ipf_handle_frag(struct ipf *ipf, struct dp_packet *pkt, ovs_be16 dl_type,
+ uint16_t zone, long long now, uint32_t hash_basis,
+ bool dnsteal)
+ OVS_REQUIRES(ipf->ipf_lock)
+{
+ struct ipf_list_key key;
+ /* Initialize 4 variables for some versions of GCC. */
+ uint16_t start_data_byte = 0;
+ uint16_t end_data_byte = 0;
+ bool ff = false;
+ bool lf = false;
+ bool v6 = dl_type == htons(ETH_TYPE_IPV6);
+
+ if (v6 && ipf_get_v6_enabled(ipf)) {
+ ipf_v6_key_extract(pkt, dl_type, zone, &key, &start_data_byte,
+ &end_data_byte, &ff, &lf);
+ } else if (!v6 && ipf_get_v4_enabled(ipf)) {
+ ipf_v4_key_extract(pkt, dl_type, zone, &key, &start_data_byte,
+ &end_data_byte, &ff, &lf);
+ } else {
+ return false;
+ }
+
+ unsigned int nfrag_max;
+ atomic_read_relaxed(&ipf->nfrag_max, &nfrag_max);
+ if (atomic_count_get(&ipf->nfrag) >= nfrag_max) {
+ return false;
+ }
+
+ uint32_t hash = ipf_list_key_hash(&key, hash_basis);
+ struct ipf_list *ipf_list = ipf_list_key_lookup(ipf, &key, hash);
+ enum {
+ IPF_FRAG_LIST_MIN_INCREMENT = 4,
+ IPF_IPV6_MAX_FRAG_LIST_SIZE = 65535,
+ };
+
+ int max_frag_list_size;
+ if (v6) {
+ /* Because the calculation with extension headers is variable,
+ * we don't calculate a hard maximum fragment list size upfront. The
+ * fragment list size is practically limited by the code, however. */
+ max_frag_list_size = IPF_IPV6_MAX_FRAG_LIST_SIZE;
+ } else {
+ max_frag_list_size = ipf->max_v4_frag_list_size;
+ }
+
+ if (!ipf_list) {
+ ipf_list = xmalloc(sizeof *ipf_list);
+ ipf_list_init(ipf_list, &key,
+ MIN(max_frag_list_size, IPF_FRAG_LIST_MIN_INCREMENT));
+ hmap_insert(&ipf->frag_lists, &ipf_list->node, hash);
+ ipf_expiry_list_add(&ipf->frag_exp_list, ipf_list, now);
+ } else if (ipf_list->state == IPF_LIST_STATE_REASS_FAIL) {
+ /* Bail out as early as possible. */
+ return false;
+ } else if (ipf_list->last_inuse_idx + 1 >= ipf_list->size) {
+ int increment = MIN(IPF_FRAG_LIST_MIN_INCREMENT,
+ max_frag_list_size - ipf_list->size);
+ /* Enforce limit. */
+ if (increment > 0) {
+ ipf_list->frag_list =
+ xrealloc(ipf_list->frag_list, (ipf_list->size + increment) *
+ sizeof *ipf_list->frag_list);
+ ipf_list->size += increment;
+ } else {
+ return false;
+ }
+ }
+
+ return ipf_process_frag(ipf, ipf_list, pkt, start_data_byte,
+ end_data_byte, ff, lf, v6, dnsteal);
+}
+
+/* Filters out fragments from a batch of fragments and adjust the batch. */
+static void
+ipf_extract_frags_from_batch(struct ipf *ipf, struct dp_packet_batch *pb,
+ ovs_be16 dl_type, uint16_t zone, long long now,
+ uint32_t hash_basis)
+{
+ const size_t pb_cnt = dp_packet_batch_size(pb);
+ int pb_idx; /* Index in a packet batch. */
+ struct dp_packet *pkt;
+
+ DP_PACKET_BATCH_REFILL_FOR_EACH (pb_idx, pb_cnt, pkt, pb) {
+ if (OVS_UNLIKELY((dl_type == htons(ETH_TYPE_IP) &&
+ ipf_is_valid_v4_frag(ipf, pkt))
+ ||
+ (dl_type == htons(ETH_TYPE_IPV6) &&
+ ipf_is_valid_v6_frag(ipf, pkt)))) {
+
+ ovs_mutex_lock(&ipf->ipf_lock);
+ if (!ipf_handle_frag(ipf, pkt, dl_type, zone, now, hash_basis,
+ pb->do_not_steal)) {
+ dp_packet_batch_refill(pb, pkt, pb_idx);
+ }
+ ovs_mutex_unlock(&ipf->ipf_lock);
+ } else {
+ dp_packet_batch_refill(pb, pkt, pb_idx);
+ }
+ }
+}
+
+/* In case of DPDK, a memory source check is done, as DPDK memory pool
+ * management has trouble dealing with multiple source types. The
+ * check_source paramater is used to indicate when this check is needed. */
+static bool
+ipf_dp_packet_batch_add(struct dp_packet_batch *pb , struct dp_packet *pkt,
+ bool check_source OVS_UNUSED)
+{
+#ifdef DPDK_NETDEV
+ if ((dp_packet_batch_is_full(pb)) ||
+ /* DPDK cannot handle multiple sources in a batch. */
+ (check_source && !dp_packet_batch_is_empty(pb)
+ && pb->packets[0]->source != pkt->source)) {
+#else
+ if (dp_packet_batch_is_full(pb)) {
+#endif
+ return false;
+ }
+
+ dp_packet_batch_add(pb, pkt);
+ return true;
+}
+
+/* This would be used in rare cases where a list cannot be sent. One rare
+ * reason known right now is a mempool source check, which exists due to DPDK
+ * support, where packets are no longer being received on any port with a
+ * source matching the fragment. Another reason is a race where all
+ * conntrack rules are unconfigured when some fragments are yet to be
+ * flushed.
+ *
+ * Returns true if the list was purged. */
+static bool
+ipf_purge_list_check(struct ipf *ipf, struct ipf_list *ipf_list,
+ long long now)
+ OVS_REQUIRES(ipf->ipf_lock)
+{
+ enum {
+ IPF_FRAG_LIST_PURGE_TIME_ADJ = 10000
+ };
+
+ if (now < ipf_list->expiration + IPF_FRAG_LIST_PURGE_TIME_ADJ) {
+ return false;
+ }
+
+ while (ipf_list->last_sent_idx < ipf_list->last_inuse_idx) {
+ struct dp_packet * pkt
+ = ipf_list->frag_list[ipf_list->last_sent_idx + 1].pkt;
+ dp_packet_delete(pkt);
+ atomic_count_dec(&ipf->nfrag);
+ COVERAGE_INC(ipf_stuck_frag_list_purged);
+ ipf_count(ipf, ipf_list->key.dl_type == htons(ETH_TYPE_IPV6),
+ IPF_NFRAGS_PURGED);
+ ipf_list->last_sent_idx++;
+ }
+
+ return true;
+}
+
+/* Does the packet batch management and common accounting work associated
+ * with 'ipf_send_completed_frags()' and 'ipf_send_expired_frags()'. */
+static bool
+ipf_send_frags_in_list(struct ipf *ipf, struct ipf_list *ipf_list,
+ struct dp_packet_batch *pb,
+ enum ipf_list_type list_type, bool v6, long long now)
+ OVS_REQUIRES(ipf->ipf_lock)
+{
+ if (ipf_purge_list_check(ipf, ipf_list, now)) {
+ return true;
+ }
+
+ while (ipf_list->last_sent_idx < ipf_list->last_inuse_idx) {
+ struct dp_packet *pkt
+ = ipf_list->frag_list[ipf_list->last_sent_idx + 1].pkt;
+ if (ipf_dp_packet_batch_add(pb, pkt, true)) {
+ ipf_list->last_sent_idx++;
+ atomic_count_dec(&ipf->nfrag);
+
+ if (list_type == IPF_FRAG_COMPLETED_LIST) {
+ ipf_count(ipf, v6, IPF_NFRAGS_COMPL_SENT);
+ } else {
+ ipf_count(ipf, v6, IPF_NFRAGS_EXPD_SENT);
+ pkt->md.ct_state = CS_INVALID;
+ }
+
+ if (ipf_list->last_sent_idx == ipf_list->last_inuse_idx) {
+ return true;
+ }
+ } else {
+ return false;
+ }
+ }
+ OVS_NOT_REACHED();
+}
+
+/* Adds fragments associated with a completed fragment list to a packet batch
+ * to be processed by the calling application, typically conntrack. Also
+ * cleans up the list context when it is empty.*/
+static void
+ipf_send_completed_frags(struct ipf *ipf, struct dp_packet_batch *pb,
+ long long now, bool v6)
+{
+ if (ovs_list_is_empty(&ipf->frag_complete_list)) {
+ return;
+ }
+
+ ovs_mutex_lock(&ipf->ipf_lock);
+ struct ipf_list *ipf_list, *next;
+
+ LIST_FOR_EACH_SAFE (ipf_list, next, list_node, &ipf->frag_complete_list) {
+ if (ipf_send_frags_in_list(ipf, ipf_list, pb, IPF_FRAG_COMPLETED_LIST,
+ v6, now)) {
+ ipf_completed_list_clean(&ipf->frag_lists, ipf_list);
+ } else {
+ break;
+ }
+ }
+
+ ovs_mutex_unlock(&ipf->ipf_lock);
+}
+
+/* Conservatively adds fragments associated with a expired fragment list to
+ * a packet batch to be processed by the calling application, typically
+ * conntrack. Also cleans up the list context when it is empty.*/
+static void
+ipf_send_expired_frags(struct ipf *ipf, struct dp_packet_batch *pb,
+ long long now, bool v6)
+{
+ enum {
+ /* Very conservative, due to DOS probability. */
+ IPF_FRAG_LIST_MAX_EXPIRED = 1,
+ };
+
+
+ if (ovs_list_is_empty(&ipf->frag_exp_list)) {
+ return;
+ }
+
+ ovs_mutex_lock(&ipf->ipf_lock);
+ struct ipf_list *ipf_list, *next;
+ size_t lists_removed = 0;
+
+ LIST_FOR_EACH_SAFE (ipf_list, next, list_node, &ipf->frag_exp_list) {
+ if (now <= ipf_list->expiration ||
+ lists_removed >= IPF_FRAG_LIST_MAX_EXPIRED) {
+ break;
+ }
+
+ if (ipf_send_frags_in_list(ipf, ipf_list, pb, IPF_FRAG_EXPIRY_LIST,
+ v6, now)) {
+ ipf_expiry_list_clean(&ipf->frag_lists, ipf_list);
+ lists_removed++;
+ } else {
+ break;
+ }
+ }
+
+ ovs_mutex_unlock(&ipf->ipf_lock);
+}
+
+/* Adds a reassmebled packet to a packet batch to be processed by the caller.
+ */
+static void
+ipf_execute_reass_pkts(struct ipf *ipf, struct dp_packet_batch *pb)
+{
+ if (ovs_list_is_empty(&ipf->reassembled_pkt_list)) {
+ return;
+ }
+
+ ovs_mutex_lock(&ipf->ipf_lock);
+ struct reassembled_pkt *rp, *next;
+
+ LIST_FOR_EACH_SAFE (rp, next, rp_list_node, &ipf->reassembled_pkt_list) {
+ if (!rp->list->reass_execute_ctx &&
+ ipf_dp_packet_batch_add(pb, rp->pkt, false)) {
+ rp->list->reass_execute_ctx = rp->pkt;
+ }
+ }
+
+ ovs_mutex_unlock(&ipf->ipf_lock);
+}
+
+/* Checks for reassembled packets post processing by conntrack and edits the
+ * fragments if needed based on what conntrack decided. */
+static void
+ipf_post_execute_reass_pkts(struct ipf *ipf,
+ struct dp_packet_batch *pb, bool v6)
+{
+ if (ovs_list_is_empty(&ipf->reassembled_pkt_list)) {
+ return;
+ }
+
+ ovs_mutex_lock(&ipf->ipf_lock);
+ struct reassembled_pkt *rp, *next;
+
+ LIST_FOR_EACH_SAFE (rp, next, rp_list_node, &ipf->reassembled_pkt_list) {
+ const size_t pb_cnt = dp_packet_batch_size(pb);
+ int pb_idx;
+ struct dp_packet *pkt;
+ /* Inner batch loop is constant time since batch size is <=
+ * NETDEV_MAX_BURST. */
+ DP_PACKET_BATCH_REFILL_FOR_EACH (pb_idx, pb_cnt, pkt, pb) {
+ if (pkt == rp->list->reass_execute_ctx) {
+ for (int i = 0; i <= rp->list->last_inuse_idx; i++) {
+ rp->list->frag_list[i].pkt->md.ct_label = pkt->md.ct_label;
+ rp->list->frag_list[i].pkt->md.ct_mark = pkt->md.ct_mark;
+ rp->list->frag_list[i].pkt->md.ct_state = pkt->md.ct_state;
+ rp->list->frag_list[i].pkt->md.ct_zone = pkt->md.ct_zone;
+ rp->list->frag_list[i].pkt->md.ct_orig_tuple_ipv6 =
+ pkt->md.ct_orig_tuple_ipv6;
+ if (pkt->md.ct_orig_tuple_ipv6) {
+ rp->list->frag_list[i].pkt->md.ct_orig_tuple.ipv6 =
+ pkt->md.ct_orig_tuple.ipv6;
+ } else {
+ rp->list->frag_list[i].pkt->md.ct_orig_tuple.ipv4 =
+ pkt->md.ct_orig_tuple.ipv4;
+ }
+ }
+
+ const struct ipf_frag *frag_0 = &rp->list->frag_list[0];
+ const char *tail_frag = dp_packet_tail(frag_0->pkt);
+ uint8_t pad_frag = dp_packet_l2_pad_size(frag_0->pkt);
+ void *l4_frag = dp_packet_l4(frag_0->pkt);
+ void *l4_reass = dp_packet_l4(pkt);
+ memcpy(l4_frag, l4_reass,
+ tail_frag - (char *) l4_frag - pad_frag);
+
+ if (v6) {
+ struct ovs_16aligned_ip6_hdr *l3_frag
+ = dp_packet_l3(frag_0->pkt);
+ struct ovs_16aligned_ip6_hdr *l3_reass = dp_packet_l3(pkt);
+ l3_frag->ip6_src = l3_reass->ip6_src;
+ l3_frag->ip6_dst = l3_reass->ip6_dst;
+ } else {
+ struct ip_header *l3_frag = dp_packet_l3(frag_0->pkt);
+ struct ip_header *l3_reass = dp_packet_l3(pkt);
+ ovs_be32 reass_ip = get_16aligned_be32(&l3_reass->ip_src);
+ ovs_be32 frag_ip = get_16aligned_be32(&l3_frag->ip_src);
+ l3_frag->ip_csum = recalc_csum32(l3_frag->ip_csum,
+ frag_ip, reass_ip);
+ l3_frag->ip_src = l3_reass->ip_src;
+
+ reass_ip = get_16aligned_be32(&l3_reass->ip_dst);
+ frag_ip = get_16aligned_be32(&l3_frag->ip_dst);
+ l3_frag->ip_csum = recalc_csum32(l3_frag->ip_csum,
+ frag_ip, reass_ip);
+ l3_frag->ip_dst = l3_reass->ip_dst;
+ }
+
+ ipf_completed_list_add(&ipf->frag_complete_list, rp->list);
+ ipf_reassembled_list_remove(rp);
+ dp_packet_delete(rp->pkt);
+ free(rp);
+ } else {
+ dp_packet_batch_refill(pb, pkt, pb_idx);
+ }
+ }
+ }
+
+ ovs_mutex_unlock(&ipf->ipf_lock);
+}
+
+/* Extracts any fragments from the batch and reassembles them when a
+ * complete packet is received. Completed packets are attempted to
+ * be added to the batch to be sent through conntrack. */
+void
+ipf_preprocess_conntrack(struct ipf *ipf, struct dp_packet_batch *pb,
+ long long now, ovs_be16 dl_type, uint16_t zone,
+ uint32_t hash_basis)
+{
+ if (ipf_get_enabled(ipf)) {
+ ipf_extract_frags_from_batch(ipf, pb, dl_type, zone, now, hash_basis);
+ }
+
+ if (ipf_get_enabled(ipf) || atomic_count_get(&ipf->nfrag)) {
+ ipf_execute_reass_pkts(ipf, pb);
+ }
+}
+
+/* Updates fragments based on the processing of the reassembled packet sent
+ * through conntrack and adds these fragments to any batches seen. Expired
+ * fragments are marked as invalid and also added to the batches seen
+ * with low priority. Reassembled packets are freed. */
+void
+ipf_postprocess_conntrack(struct ipf *ipf, struct dp_packet_batch *pb,
+ long long now, ovs_be16 dl_type)
+{
+ if (ipf_get_enabled(ipf) || atomic_count_get(&ipf->nfrag)) {
+ bool v6 = dl_type == htons(ETH_TYPE_IPV6);
+ ipf_post_execute_reass_pkts(ipf, pb, v6);
+ ipf_send_completed_frags(ipf, pb, now, v6);
+ ipf_send_expired_frags(ipf, pb, now, v6);
+ }
+}
+
+static void *
+ipf_clean_thread_main(void *f)
+{
+ struct ipf *ipf = f;
+
+ enum {
+ IPF_FRAG_LIST_CLEAN_TIMEOUT = 60000,
+ };
+
+ while (!latch_is_set(&ipf->ipf_clean_thread_exit)) {
+
+ long long now = time_msec();
+
+ if (!ovs_list_is_empty(&ipf->frag_exp_list) ||
+ !ovs_list_is_empty(&ipf->frag_complete_list)) {
+
+ ovs_mutex_lock(&ipf->ipf_lock);
+
+ struct ipf_list *ipf_list, *next;
+ LIST_FOR_EACH_SAFE (ipf_list, next, list_node,
+ &ipf->frag_exp_list) {
+ if (ipf_purge_list_check(ipf, ipf_list, now)) {
+ ipf_expiry_list_clean(&ipf->frag_lists, ipf_list);
+ }
+ }
+
+ LIST_FOR_EACH_SAFE (ipf_list, next, list_node,
+ &ipf->frag_complete_list) {
+ if (ipf_purge_list_check(ipf, ipf_list, now)) {
+ ipf_completed_list_clean(&ipf->frag_lists, ipf_list);
+ }
+ }
+
+ ovs_mutex_unlock(&ipf->ipf_lock);
+ }
+
+ poll_timer_wait_until(now + IPF_FRAG_LIST_CLEAN_TIMEOUT);
+ latch_wait(&ipf->ipf_clean_thread_exit);
+ poll_block();
+ }
+
+ return NULL;
+}
+
+struct ipf *
+ipf_init(void)
+{
+ struct ipf *ipf = xzalloc(sizeof *ipf);
+
+ ovs_mutex_init_adaptive(&ipf->ipf_lock);
+ ovs_mutex_lock(&ipf->ipf_lock);
+ hmap_init(&ipf->frag_lists);
+ ovs_list_init(&ipf->frag_exp_list);
+ ovs_list_init(&ipf->frag_complete_list);
+ ovs_list_init(&ipf->reassembled_pkt_list);
+ atomic_init(&ipf->min_v4_frag_size, IPF_V4_FRAG_SIZE_MIN_DEF);
+ atomic_init(&ipf->min_v6_frag_size, IPF_V6_FRAG_SIZE_MIN_DEF);
+ ipf->max_v4_frag_list_size = DIV_ROUND_UP(
+ IPV4_PACKET_MAX_SIZE - IPV4_PACKET_MAX_HDR_SIZE,
+ ipf->min_v4_frag_size - IPV4_PACKET_MAX_HDR_SIZE);
+ ovs_mutex_unlock(&ipf->ipf_lock);
+ atomic_count_init(&ipf->nfrag, 0);
+ for (size_t i = 0; i < IPF_NFRAGS_NUM_CNTS; i++) {
+ atomic_init(&ipf->n4frag_cnt[i], 0);
+ atomic_init(&ipf->n6frag_cnt[i], 0);
+ }
+ atomic_init(&ipf->nfrag_max, IPF_MAX_FRAGS_DEFAULT);
+ atomic_init(&ipf->ifp_v4_enabled, true);
+ atomic_init(&ipf->ifp_v6_enabled, true);
+ latch_init(&ipf->ipf_clean_thread_exit);
+ ipf->ipf_clean_thread = ovs_thread_create("ipf_clean",
+ ipf_clean_thread_main, ipf);
+
+ return ipf;
+}
+
+void
+ipf_destroy(struct ipf *ipf)
+{
+ ovs_mutex_lock(&ipf->ipf_lock);
+ latch_set(&ipf->ipf_clean_thread_exit);
+ pthread_join(ipf->ipf_clean_thread, NULL);
+ latch_destroy(&ipf->ipf_clean_thread_exit);
+
+ struct ipf_list *ipf_list;
+ HMAP_FOR_EACH_POP (ipf_list, node, &ipf->frag_lists) {
+ while (ipf_list->last_sent_idx < ipf_list->last_inuse_idx) {
+ struct dp_packet *pkt
+ = ipf_list->frag_list[ipf_list->last_sent_idx + 1].pkt;
+ if (!ipf_list->frag_list[ipf_list->last_sent_idx + 1].dnsteal) {
+ dp_packet_delete(pkt);
+ }
+ atomic_count_dec(&ipf->nfrag);
+ ipf_list->last_sent_idx++;
+ }
+ free(ipf_list->frag_list);
+ free(ipf_list);
+ }
+
+ if (atomic_count_get(&ipf->nfrag)) {
+ VLOG_WARN("ipf destroy with non-zero fragment count. ");
+ }
+
+ struct reassembled_pkt *rp;
+ LIST_FOR_EACH_POP (rp, rp_list_node, &ipf->reassembled_pkt_list) {
+ dp_packet_delete(rp->pkt);
+ free(rp);
+ }
+
+ hmap_destroy(&ipf->frag_lists);
+ ovs_list_poison(&ipf->frag_exp_list);
+ ovs_list_poison(&ipf->frag_complete_list);
+ ovs_list_poison(&ipf->reassembled_pkt_list);
+ ovs_mutex_unlock(&ipf->ipf_lock);
+ ovs_mutex_destroy(&ipf->ipf_lock);
+ free(ipf);
+}
+
+int
+ipf_set_enabled(struct ipf *ipf, bool v6, bool enable)
+{
+ atomic_store_relaxed(v6 ? &ipf->ifp_v6_enabled : &ipf->ifp_v4_enabled,
+ enable);
+ return 0;
+}
+
+int
+ipf_set_min_frag(struct ipf *ipf, bool v6, uint32_t value)
+{
+ /* If the user specifies an unreasonably large number, fragmentation
+ * will not work well but it will not blow up. */
+ if (value < (v6 ? IPF_V6_FRAG_SIZE_LBOUND : IPF_V4_FRAG_SIZE_LBOUND)) {
+ return 1;
+ }
+
+ ovs_mutex_lock(&ipf->ipf_lock);
+ if (v6) {
+ atomic_store_relaxed(&ipf->min_v6_frag_size, value);
+ } else {
+ atomic_store_relaxed(&ipf->min_v4_frag_size, value);
+ ipf->max_v4_frag_list_size = DIV_ROUND_UP(
+ IPV4_PACKET_MAX_SIZE - IPV4_PACKET_MAX_HDR_SIZE,
+ ipf->min_v4_frag_size - IPV4_PACKET_MAX_HDR_SIZE);
+ }
+ ovs_mutex_unlock(&ipf->ipf_lock);
+ return 0;
+}
+
+int
+ipf_set_max_nfrags(struct ipf *ipf, uint32_t value)
+{
+ if (value > IPF_NFRAG_UBOUND) {
+ return 1;
+ }
+ atomic_store_relaxed(&ipf->nfrag_max, value);
+ return 0;
+}
+
+int
+ipf_get_status(struct ipf *ipf, struct ipf_status *ipf_status)
+{
+ ipf_status->nfrag = atomic_count_get(&ipf->nfrag);
+ atomic_read_relaxed(&ipf->nfrag_max, &ipf_status->nfrag_max);
+
+ atomic_read_relaxed(&ipf->ifp_v4_enabled, &ipf_status->v4.enabled);
+ atomic_read_relaxed(&ipf->min_v4_frag_size,
+ &ipf_status->v4.min_frag_size);
+ atomic_read_relaxed(&ipf->n4frag_cnt[IPF_NFRAGS_ACCEPTED],
+ &ipf_status->v4.nfrag_accepted);
+ atomic_read_relaxed(&ipf->n4frag_cnt[IPF_NFRAGS_COMPL_SENT],
+ &ipf_status->v4.nfrag_completed_sent);
+ atomic_read_relaxed(&ipf->n4frag_cnt[IPF_NFRAGS_EXPD_SENT],
+ &ipf_status->v4.nfrag_expired_sent);
+ atomic_read_relaxed(&ipf->n4frag_cnt[IPF_NFRAGS_TOO_SMALL],
+ &ipf_status->v4.nfrag_too_small);
+ atomic_read_relaxed(&ipf->n4frag_cnt[IPF_NFRAGS_OVERLAP],
+ &ipf_status->v4.nfrag_overlap);
+ atomic_read_relaxed(&ipf->n4frag_cnt[IPF_NFRAGS_PURGED],
+ &ipf_status->v4.nfrag_purged);
+
+ atomic_read_relaxed(&ipf->ifp_v6_enabled, &ipf_status->v6.enabled);
+ atomic_read_relaxed(&ipf->min_v6_frag_size,
+ &ipf_status->v6.min_frag_size);
+ atomic_read_relaxed(&ipf->n6frag_cnt[IPF_NFRAGS_ACCEPTED],
+ &ipf_status->v6.nfrag_accepted);
+ atomic_read_relaxed(&ipf->n6frag_cnt[IPF_NFRAGS_COMPL_SENT],
+ &ipf_status->v6.nfrag_completed_sent);
+ atomic_read_relaxed(&ipf->n6frag_cnt[IPF_NFRAGS_EXPD_SENT],
+ &ipf_status->v6.nfrag_expired_sent);
+ atomic_read_relaxed(&ipf->n6frag_cnt[IPF_NFRAGS_TOO_SMALL],
+ &ipf_status->v6.nfrag_too_small);
+ atomic_read_relaxed(&ipf->n6frag_cnt[IPF_NFRAGS_OVERLAP],
+ &ipf_status->v6.nfrag_overlap);
+ atomic_read_relaxed(&ipf->n6frag_cnt[IPF_NFRAGS_PURGED],
+ &ipf_status->v6.nfrag_purged);
+ return 0;
+}
+
+struct ipf_dump_ctx {
+ struct hmap_position bucket_pos;
+};
+
+/* Allocates an 'ipf_dump_ctx' to keep track of an hmap position. The
+ * caller must call ipf_dump_done() when dumping is finished. */
+int
+ipf_dump_start(struct ipf_dump_ctx **ipf_dump_ctx)
+{
+ *ipf_dump_ctx = xzalloc(sizeof **ipf_dump_ctx);
+ return 0;
+}
+
+/* Creates a string representation of the state of an 'ipf_list' and puts
+ * it in 'ds'. */
+static void
+ipf_dump_create(const struct ipf_list *ipf_list, struct ds *ds)
+{
+ ds_put_cstr(ds, "(");
+ if (ipf_list->key.dl_type == htons(ETH_TYPE_IP)) {
+ ds_put_format(ds, "src="IP_FMT",dst="IP_FMT",",
+ IP_ARGS(ipf_list->key.src_addr.ipv4),
+ IP_ARGS(ipf_list->key.dst_addr.ipv4));
+ } else {
+ ds_put_cstr(ds, "src=");
+ ipv6_format_addr(&ipf_list->key.src_addr.ipv6, ds);
+ ds_put_cstr(ds, ",dst=");
+ ipv6_format_addr(&ipf_list->key.dst_addr.ipv6, ds);
+ ds_put_cstr(ds, ",");
+ }
+
+ ds_put_format(ds, "recirc_id=%u,ip_id=%u,dl_type=0x%x,zone=%u,nw_proto=%u",
+ ipf_list->key.recirc_id, ntohl(ipf_list->key.ip_id),
+ ntohs(ipf_list->key.dl_type), ipf_list->key.zone,
+ ipf_list->key.nw_proto);
+
+ ds_put_format(ds, ",num_fragments=%u,state=%s",
+ ipf_list->last_inuse_idx + 1,
+ ipf_state_name[ipf_list->state]);
+
+ ds_put_cstr(ds, ")");
+}
+
+/* Finds the next ipf list starting from 'ipf_dump_ctx->bucket_pos' and uses
+ * ipf_dump_create() to create a string representation of the state of an
+ * ipf list, to which 'dump' is pointed to. Returns EOF when there are no
+ * more ipf lists. */
+int
+ipf_dump_next(struct ipf *ipf, struct ipf_dump_ctx *ipf_dump_ctx, char **dump)
+{
+ ovs_mutex_lock(&ipf->ipf_lock);
+
+ struct hmap_node *node = hmap_at_position(&ipf->frag_lists,
+ &ipf_dump_ctx->bucket_pos);
+ if (!node) {
+ ovs_mutex_unlock(&ipf->ipf_lock);
+ return EOF;
+ } else {
+ struct ipf_list *ipf_list_;
+ INIT_CONTAINER(ipf_list_, node, node);
+ struct ipf_list ipf_list = *ipf_list_;
+ ovs_mutex_unlock(&ipf->ipf_lock);
+ struct ds ds = DS_EMPTY_INITIALIZER;
+ ipf_dump_create(&ipf_list, &ds);
+ *dump = ds_steal_cstr(&ds);
+ return 0;
+ }
+}
+
+/* Frees 'ipf_dump_ctx' allocated by ipf_dump_start(). */
+int
+ipf_dump_done(struct ipf_dump_ctx *ipf_dump_ctx)
+{
+ free(ipf_dump_ctx);
+ return 0;
+}