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Diffstat (limited to 'net/dccp/ipv4.c')
-rw-r--r--net/dccp/ipv4.c537
1 files changed, 228 insertions, 309 deletions
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index e08e7688a263..ff81679c9f17 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -113,13 +113,8 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
/* OK, now commit destination to socket. */
sk_setup_caps(sk, &rt->u.dst);
- dp->dccps_gar =
- dp->dccps_iss = secure_dccp_sequence_number(inet->saddr,
- inet->daddr,
- inet->sport,
- usin->sin_port);
- dccp_update_gss(sk, dp->dccps_iss);
-
+ dp->dccps_iss = secure_dccp_sequence_number(inet->saddr, inet->daddr,
+ inet->sport, inet->dport);
inet->id = dp->dccps_iss ^ jiffies;
err = dccp_connect(sk);
@@ -193,86 +188,6 @@ static inline void dccp_do_pmtu_discovery(struct sock *sk,
} /* else let the usual retransmit timer handle it */
}
-static void dccp_v4_reqsk_send_ack(struct sk_buff *rxskb,
- struct request_sock *req)
-{
- int err;
- struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
- const u32 dccp_hdr_ack_len = sizeof(struct dccp_hdr) +
- sizeof(struct dccp_hdr_ext) +
- sizeof(struct dccp_hdr_ack_bits);
- struct sk_buff *skb;
-
- if (((struct rtable *)rxskb->dst)->rt_type != RTN_LOCAL)
- return;
-
- skb = alloc_skb(dccp_v4_ctl_socket->sk->sk_prot->max_header, GFP_ATOMIC);
- if (skb == NULL)
- return;
-
- /* Reserve space for headers. */
- skb_reserve(skb, dccp_v4_ctl_socket->sk->sk_prot->max_header);
-
- skb->dst = dst_clone(rxskb->dst);
-
- skb->h.raw = skb_push(skb, dccp_hdr_ack_len);
- dh = dccp_hdr(skb);
- memset(dh, 0, dccp_hdr_ack_len);
-
- /* Build DCCP header and checksum it. */
- dh->dccph_type = DCCP_PKT_ACK;
- dh->dccph_sport = rxdh->dccph_dport;
- dh->dccph_dport = rxdh->dccph_sport;
- dh->dccph_doff = dccp_hdr_ack_len / 4;
- dh->dccph_x = 1;
-
- dccp_hdr_set_seq(dh, DCCP_SKB_CB(rxskb)->dccpd_ack_seq);
- dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
- DCCP_SKB_CB(rxskb)->dccpd_seq);
-
- bh_lock_sock(dccp_v4_ctl_socket->sk);
- err = ip_build_and_send_pkt(skb, dccp_v4_ctl_socket->sk,
- rxskb->nh.iph->daddr,
- rxskb->nh.iph->saddr, NULL);
- bh_unlock_sock(dccp_v4_ctl_socket->sk);
-
- if (err == NET_XMIT_CN || err == 0) {
- DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
- DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
- }
-}
-
-static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
- struct dst_entry *dst)
-{
- int err = -1;
- struct sk_buff *skb;
-
- /* First, grab a route. */
-
- if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
- goto out;
-
- skb = dccp_make_response(sk, dst, req);
- if (skb != NULL) {
- const struct inet_request_sock *ireq = inet_rsk(req);
- struct dccp_hdr *dh = dccp_hdr(skb);
-
- dh->dccph_checksum = dccp_v4_checksum(skb, ireq->loc_addr,
- ireq->rmt_addr);
- memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
- err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
- ireq->rmt_addr,
- ireq->opt);
- if (err == NET_XMIT_CN)
- err = 0;
- }
-
-out:
- dst_release(dst);
- return err;
-}
-
/*
* This routine is called by the ICMP module when it gets some sort of error
* condition. If err < 0 then the socket should be closed and the error
@@ -329,7 +244,7 @@ static void dccp_v4_err(struct sk_buff *skb, u32 info)
seq = dccp_hdr_seq(skb);
if (sk->sk_state != DCCP_LISTEN &&
!between48(seq, dp->dccps_swl, dp->dccps_swh)) {
- NET_INC_STATS(LINUX_MIB_OUTOFWINDOWICMPS);
+ NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
goto out;
}
@@ -429,19 +344,24 @@ out:
sock_put(sk);
}
-/* This routine computes an IPv4 DCCP checksum. */
-void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
+static inline __sum16 dccp_v4_csum_finish(struct sk_buff *skb,
+ __be32 src, __be32 dst)
+{
+ return csum_tcpudp_magic(src, dst, skb->len, IPPROTO_DCCP, skb->csum);
+}
+
+void dccp_v4_send_check(struct sock *sk, int unused, struct sk_buff *skb)
{
const struct inet_sock *inet = inet_sk(sk);
struct dccp_hdr *dh = dccp_hdr(skb);
- dh->dccph_checksum = dccp_v4_checksum(skb, inet->saddr, inet->daddr);
+ dccp_csum_outgoing(skb);
+ dh->dccph_checksum = dccp_v4_csum_finish(skb, inet->saddr, inet->daddr);
}
EXPORT_SYMBOL_GPL(dccp_v4_send_check);
-static inline u64 dccp_v4_init_sequence(const struct sock *sk,
- const struct sk_buff *skb)
+static inline u64 dccp_v4_init_sequence(const struct sk_buff *skb)
{
return secure_dccp_sequence_number(skb->nh.iph->daddr,
skb->nh.iph->saddr,
@@ -449,95 +369,6 @@ static inline u64 dccp_v4_init_sequence(const struct sock *sk,
dccp_hdr(skb)->dccph_sport);
}
-static struct request_sock_ops dccp_request_sock_ops;
-
-int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
-{
- struct inet_request_sock *ireq;
- struct dccp_sock dp;
- struct request_sock *req;
- struct dccp_request_sock *dreq;
- const __be32 saddr = skb->nh.iph->saddr;
- const __be32 daddr = skb->nh.iph->daddr;
- const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
- struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
- __u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
-
- /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
- if (((struct rtable *)skb->dst)->rt_flags &
- (RTCF_BROADCAST | RTCF_MULTICAST)) {
- reset_code = DCCP_RESET_CODE_NO_CONNECTION;
- goto drop;
- }
-
- if (dccp_bad_service_code(sk, service)) {
- reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
- goto drop;
- }
- /*
- * TW buckets are converted to open requests without
- * limitations, they conserve resources and peer is
- * evidently real one.
- */
- if (inet_csk_reqsk_queue_is_full(sk))
- goto drop;
-
- /*
- * Accept backlog is full. If we have already queued enough
- * of warm entries in syn queue, drop request. It is better than
- * clogging syn queue with openreqs with exponentially increasing
- * timeout.
- */
- if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
- goto drop;
-
- req = reqsk_alloc(&dccp_request_sock_ops);
- if (req == NULL)
- goto drop;
-
- if (dccp_parse_options(sk, skb))
- goto drop_and_free;
-
- dccp_openreq_init(req, &dp, skb);
-
- if (security_inet_conn_request(sk, skb, req))
- goto drop_and_free;
-
- ireq = inet_rsk(req);
- ireq->loc_addr = daddr;
- ireq->rmt_addr = saddr;
- req->rcv_wnd = dccp_feat_default_sequence_window;
- ireq->opt = NULL;
-
- /*
- * Step 3: Process LISTEN state
- *
- * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
- *
- * In fact we defer setting S.GSR, S.SWL, S.SWH to
- * dccp_create_openreq_child.
- */
- dreq = dccp_rsk(req);
- dreq->dreq_isr = dcb->dccpd_seq;
- dreq->dreq_iss = dccp_v4_init_sequence(sk, skb);
- dreq->dreq_service = service;
-
- if (dccp_v4_send_response(sk, req, NULL))
- goto drop_and_free;
-
- inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
- return 0;
-
-drop_and_free:
- reqsk_free(req);
-drop:
- DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
- dcb->dccpd_reset_code = reset_code;
- return -1;
-}
-
-EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
-
/*
* The three way handshake has completed - we got a valid ACK or DATAACK -
* now create the new socket.
@@ -623,47 +454,6 @@ static struct sock *dccp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
return sk;
}
-int dccp_v4_checksum(const struct sk_buff *skb, const __be32 saddr,
- const __be32 daddr)
-{
- const struct dccp_hdr* dh = dccp_hdr(skb);
- int checksum_len;
- u32 tmp;
-
- if (dh->dccph_cscov == 0)
- checksum_len = skb->len;
- else {
- checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
- checksum_len = checksum_len < skb->len ? checksum_len :
- skb->len;
- }
-
- tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
- return csum_tcpudp_magic(saddr, daddr, checksum_len,
- IPPROTO_DCCP, tmp);
-}
-
-EXPORT_SYMBOL_GPL(dccp_v4_checksum);
-
-static int dccp_v4_verify_checksum(struct sk_buff *skb,
- const __be32 saddr, const __be32 daddr)
-{
- struct dccp_hdr *dh = dccp_hdr(skb);
- int checksum_len;
- u32 tmp;
-
- if (dh->dccph_cscov == 0)
- checksum_len = skb->len;
- else {
- checksum_len = (dh->dccph_cscov + dh->dccph_x) * sizeof(u32);
- checksum_len = checksum_len < skb->len ? checksum_len :
- skb->len;
- }
- tmp = csum_partial((unsigned char *)dh, checksum_len, 0);
- return csum_tcpudp_magic(saddr, daddr, checksum_len,
- IPPROTO_DCCP, tmp) == 0 ? 0 : -1;
-}
-
static struct dst_entry* dccp_v4_route_skb(struct sock *sk,
struct sk_buff *skb)
{
@@ -689,7 +479,37 @@ static struct dst_entry* dccp_v4_route_skb(struct sock *sk,
return &rt->u.dst;
}
-static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
+static int dccp_v4_send_response(struct sock *sk, struct request_sock *req,
+ struct dst_entry *dst)
+{
+ int err = -1;
+ struct sk_buff *skb;
+
+ /* First, grab a route. */
+
+ if (dst == NULL && (dst = inet_csk_route_req(sk, req)) == NULL)
+ goto out;
+
+ skb = dccp_make_response(sk, dst, req);
+ if (skb != NULL) {
+ const struct inet_request_sock *ireq = inet_rsk(req);
+ struct dccp_hdr *dh = dccp_hdr(skb);
+
+ dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr,
+ ireq->rmt_addr);
+ memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+ err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
+ ireq->rmt_addr,
+ ireq->opt);
+ err = net_xmit_eval(err);
+ }
+
+out:
+ dst_release(dst);
+ return err;
+}
+
+static void dccp_v4_ctl_send_reset(struct sock *sk, struct sk_buff *rxskb)
{
int err;
struct dccp_hdr *rxdh = dccp_hdr(rxskb), *dh;
@@ -698,7 +518,7 @@ static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
sizeof(struct dccp_hdr_reset);
struct sk_buff *skb;
struct dst_entry *dst;
- u64 seqno;
+ u64 seqno = 0;
/* Never send a reset in response to a reset. */
if (rxdh->dccph_type == DCCP_PKT_RESET)
@@ -720,9 +540,7 @@ static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
skb_reserve(skb, dccp_v4_ctl_socket->sk->sk_prot->max_header);
skb->dst = dst_clone(dst);
- skb->h.raw = skb_push(skb, dccp_hdr_reset_len);
- dh = dccp_hdr(skb);
- memset(dh, 0, dccp_hdr_reset_len);
+ dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
/* Build DCCP header and checksum it. */
dh->dccph_type = DCCP_PKT_RESET;
@@ -734,16 +552,15 @@ static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
DCCP_SKB_CB(rxskb)->dccpd_reset_code;
/* See "8.3.1. Abnormal Termination" in RFC 4340 */
- seqno = 0;
if (DCCP_SKB_CB(rxskb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
dccp_set_seqno(&seqno, DCCP_SKB_CB(rxskb)->dccpd_ack_seq + 1);
dccp_hdr_set_seq(dh, seqno);
- dccp_hdr_set_ack(dccp_hdr_ack_bits(skb),
- DCCP_SKB_CB(rxskb)->dccpd_seq);
+ dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), DCCP_SKB_CB(rxskb)->dccpd_seq);
- dh->dccph_checksum = dccp_v4_checksum(skb, rxskb->nh.iph->saddr,
- rxskb->nh.iph->daddr);
+ dccp_csum_outgoing(skb);
+ dh->dccph_checksum = dccp_v4_csum_finish(skb, rxskb->nh.iph->saddr,
+ rxskb->nh.iph->daddr);
bh_lock_sock(dccp_v4_ctl_socket->sk);
err = ip_build_and_send_pkt(skb, dccp_v4_ctl_socket->sk,
@@ -751,7 +568,7 @@ static void dccp_v4_ctl_send_reset(struct sk_buff *rxskb)
rxskb->nh.iph->saddr, NULL);
bh_unlock_sock(dccp_v4_ctl_socket->sk);
- if (err == NET_XMIT_CN || err == 0) {
+ if (net_xmit_eval(err) == 0) {
DCCP_INC_STATS_BH(DCCP_MIB_OUTSEGS);
DCCP_INC_STATS_BH(DCCP_MIB_OUTRSTS);
}
@@ -759,6 +576,103 @@ out:
dst_release(dst);
}
+static void dccp_v4_reqsk_destructor(struct request_sock *req)
+{
+ kfree(inet_rsk(req)->opt);
+}
+
+static struct request_sock_ops dccp_request_sock_ops __read_mostly = {
+ .family = PF_INET,
+ .obj_size = sizeof(struct dccp_request_sock),
+ .rtx_syn_ack = dccp_v4_send_response,
+ .send_ack = dccp_reqsk_send_ack,
+ .destructor = dccp_v4_reqsk_destructor,
+ .send_reset = dccp_v4_ctl_send_reset,
+};
+
+int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
+{
+ struct inet_request_sock *ireq;
+ struct request_sock *req;
+ struct dccp_request_sock *dreq;
+ const __be32 service = dccp_hdr_request(skb)->dccph_req_service;
+ struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
+ __u8 reset_code = DCCP_RESET_CODE_TOO_BUSY;
+
+ /* Never answer to DCCP_PKT_REQUESTs send to broadcast or multicast */
+ if (((struct rtable *)skb->dst)->rt_flags &
+ (RTCF_BROADCAST | RTCF_MULTICAST)) {
+ reset_code = DCCP_RESET_CODE_NO_CONNECTION;
+ goto drop;
+ }
+
+ if (dccp_bad_service_code(sk, service)) {
+ reset_code = DCCP_RESET_CODE_BAD_SERVICE_CODE;
+ goto drop;
+ }
+ /*
+ * TW buckets are converted to open requests without
+ * limitations, they conserve resources and peer is
+ * evidently real one.
+ */
+ if (inet_csk_reqsk_queue_is_full(sk))
+ goto drop;
+
+ /*
+ * Accept backlog is full. If we have already queued enough
+ * of warm entries in syn queue, drop request. It is better than
+ * clogging syn queue with openreqs with exponentially increasing
+ * timeout.
+ */
+ if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
+ goto drop;
+
+ req = reqsk_alloc(&dccp_request_sock_ops);
+ if (req == NULL)
+ goto drop;
+
+ if (dccp_parse_options(sk, skb))
+ goto drop_and_free;
+
+ dccp_reqsk_init(req, skb);
+
+ if (security_inet_conn_request(sk, skb, req))
+ goto drop_and_free;
+
+ ireq = inet_rsk(req);
+ ireq->loc_addr = skb->nh.iph->daddr;
+ ireq->rmt_addr = skb->nh.iph->saddr;
+ ireq->opt = NULL;
+
+ /*
+ * Step 3: Process LISTEN state
+ *
+ * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
+ *
+ * In fact we defer setting S.GSR, S.SWL, S.SWH to
+ * dccp_create_openreq_child.
+ */
+ dreq = dccp_rsk(req);
+ dreq->dreq_isr = dcb->dccpd_seq;
+ dreq->dreq_iss = dccp_v4_init_sequence(skb);
+ dreq->dreq_service = service;
+
+ if (dccp_v4_send_response(sk, req, NULL))
+ goto drop_and_free;
+
+ inet_csk_reqsk_queue_hash_add(sk, req, DCCP_TIMEOUT_INIT);
+ return 0;
+
+drop_and_free:
+ reqsk_free(req);
+drop:
+ DCCP_INC_STATS_BH(DCCP_MIB_ATTEMPTFAILS);
+ dcb->dccpd_reset_code = reset_code;
+ return -1;
+}
+
+EXPORT_SYMBOL_GPL(dccp_v4_conn_request);
+
int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
{
struct dccp_hdr *dh = dccp_hdr(skb);
@@ -771,24 +685,23 @@ int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
/*
* Step 3: Process LISTEN state
- * If S.state == LISTEN,
- * If P.type == Request or P contains a valid Init Cookie
- * option,
- * * Must scan the packet's options to check for an Init
- * Cookie. Only the Init Cookie is processed here,
- * however; other options are processed in Step 8. This
- * scan need only be performed if the endpoint uses Init
- * Cookies *
- * * Generate a new socket and switch to that socket *
- * Set S := new socket for this port pair
- * S.state = RESPOND
- * Choose S.ISS (initial seqno) or set from Init Cookie
- * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookie
- * Continue with S.state == RESPOND
- * * A Response packet will be generated in Step 11 *
- * Otherwise,
- * Generate Reset(No Connection) unless P.type == Reset
- * Drop packet and return
+ * If P.type == Request or P contains a valid Init Cookie option,
+ * (* Must scan the packet's options to check for Init
+ * Cookies. Only Init Cookies are processed here,
+ * however; other options are processed in Step 8. This
+ * scan need only be performed if the endpoint uses Init
+ * Cookies *)
+ * (* Generate a new socket and switch to that socket *)
+ * Set S := new socket for this port pair
+ * S.state = RESPOND
+ * Choose S.ISS (initial seqno) or set from Init Cookies
+ * Initialize S.GAR := S.ISS
+ * Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
+ * Continue with S.state == RESPOND
+ * (* A Response packet will be generated in Step 11 *)
+ * Otherwise,
+ * Generate Reset(No Connection) unless P.type == Reset
+ * Drop packet and return
*
* NOTE: the check for the packet types is done in
* dccp_rcv_state_process
@@ -811,7 +724,7 @@ int dccp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
return 0;
reset:
- dccp_v4_ctl_send_reset(skb);
+ dccp_v4_ctl_send_reset(sk, skb);
discard:
kfree_skb(skb);
return 0;
@@ -819,60 +732,74 @@ discard:
EXPORT_SYMBOL_GPL(dccp_v4_do_rcv);
+/**
+ * dccp_invalid_packet - check for malformed packets
+ * Implements RFC 4340, 8.5: Step 1: Check header basics
+ * Packets that fail these checks are ignored and do not receive Resets.
+ */
int dccp_invalid_packet(struct sk_buff *skb)
{
const struct dccp_hdr *dh;
+ unsigned int cscov;
if (skb->pkt_type != PACKET_HOST)
return 1;
+ /* If the packet is shorter than 12 bytes, drop packet and return */
if (!pskb_may_pull(skb, sizeof(struct dccp_hdr))) {
- LIMIT_NETDEBUG(KERN_WARNING "DCCP: pskb_may_pull failed\n");
+ DCCP_WARN("pskb_may_pull failed\n");
return 1;
}
dh = dccp_hdr(skb);
- /* If the packet type is not understood, drop packet and return */
+ /* If P.type is not understood, drop packet and return */
if (dh->dccph_type >= DCCP_PKT_INVALID) {
- LIMIT_NETDEBUG(KERN_WARNING "DCCP: invalid packet type\n");
+ DCCP_WARN("invalid packet type\n");
return 1;
}
/*
- * If P.Data Offset is too small for packet type, or too large for
- * packet, drop packet and return
+ * If P.Data Offset is too small for packet type, drop packet and return
*/
if (dh->dccph_doff < dccp_hdr_len(skb) / sizeof(u32)) {
- LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) "
- "too small 1\n",
- dh->dccph_doff);
+ DCCP_WARN("P.Data Offset(%u) too small\n", dh->dccph_doff);
return 1;
}
-
+ /*
+ * If P.Data Offset is too too large for packet, drop packet and return
+ */
if (!pskb_may_pull(skb, dh->dccph_doff * sizeof(u32))) {
- LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.Data Offset(%u) "
- "too small 2\n",
- dh->dccph_doff);
+ DCCP_WARN("P.Data Offset(%u) too large\n", dh->dccph_doff);
return 1;
}
- dh = dccp_hdr(skb);
-
/*
* If P.type is not Data, Ack, or DataAck and P.X == 0 (the packet
* has short sequence numbers), drop packet and return
*/
- if (dh->dccph_x == 0 &&
- dh->dccph_type != DCCP_PKT_DATA &&
- dh->dccph_type != DCCP_PKT_ACK &&
- dh->dccph_type != DCCP_PKT_DATAACK) {
- LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.type (%s) not Data, Ack "
- "nor DataAck and P.X == 0\n",
- dccp_packet_name(dh->dccph_type));
+ if (dh->dccph_type >= DCCP_PKT_DATA &&
+ dh->dccph_type <= DCCP_PKT_DATAACK && dh->dccph_x == 0) {
+ DCCP_WARN("P.type (%s) not Data || [Data]Ack, while P.X == 0\n",
+ dccp_packet_name(dh->dccph_type));
return 1;
}
+ /*
+ * If P.CsCov is too large for the packet size, drop packet and return.
+ * This must come _before_ checksumming (not as RFC 4340 suggests).
+ */
+ cscov = dccp_csum_coverage(skb);
+ if (cscov > skb->len) {
+ DCCP_WARN("P.CsCov %u exceeds packet length %d\n",
+ dh->dccph_cscov, skb->len);
+ return 1;
+ }
+
+ /* If header checksum is incorrect, drop packet and return.
+ * (This step is completed in the AF-dependent functions.) */
+ skb->csum = skb_checksum(skb, 0, cscov, 0);
+
return 0;
}
@@ -883,17 +810,16 @@ static int dccp_v4_rcv(struct sk_buff *skb)
{
const struct dccp_hdr *dh;
struct sock *sk;
+ int min_cov;
- /* Step 1: Check header basics: */
+ /* Step 1: Check header basics */
if (dccp_invalid_packet(skb))
goto discard_it;
- /* If the header checksum is incorrect, drop packet and return */
- if (dccp_v4_verify_checksum(skb, skb->nh.iph->saddr,
- skb->nh.iph->daddr) < 0) {
- LIMIT_NETDEBUG(KERN_WARNING "%s: incorrect header checksum\n",
- __FUNCTION__);
+ /* Step 1: If header checksum is incorrect, drop packet and return */
+ if (dccp_v4_csum_finish(skb, skb->nh.iph->saddr, skb->nh.iph->daddr)) {
+ DCCP_WARN("dropped packet with invalid checksum\n");
goto discard_it;
}
@@ -915,8 +841,7 @@ static int dccp_v4_rcv(struct sk_buff *skb)
dccp_pr_debug_cat("\n");
} else {
DCCP_SKB_CB(skb)->dccpd_ack_seq = dccp_hdr_ack_seq(skb);
- dccp_pr_debug_cat(", ack=%llu\n",
- (unsigned long long)
+ dccp_pr_debug_cat(", ack=%llu\n", (unsigned long long)
DCCP_SKB_CB(skb)->dccpd_ack_seq);
}
@@ -930,8 +855,6 @@ static int dccp_v4_rcv(struct sk_buff *skb)
/*
* Step 2:
* If no socket ...
- * Generate Reset(No Connection) unless P.type == Reset
- * Drop packet and return
*/
if (sk == NULL) {
dccp_pr_debug("failed to look up flow ID in table and "
@@ -945,45 +868,55 @@ static int dccp_v4_rcv(struct sk_buff *skb)
* Generate Reset(No Connection) unless P.type == Reset
* Drop packet and return
*/
-
if (sk->sk_state == DCCP_TIME_WAIT) {
- dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: "
- "do_time_wait\n");
- goto do_time_wait;
+ dccp_pr_debug("sk->sk_state == DCCP_TIME_WAIT: do_time_wait\n");
+ inet_twsk_put(inet_twsk(sk));
+ goto no_dccp_socket;
+ }
+
+ /*
+ * RFC 4340, sec. 9.2.1: Minimum Checksum Coverage
+ * o if MinCsCov = 0, only packets with CsCov = 0 are accepted
+ * o if MinCsCov > 0, also accept packets with CsCov >= MinCsCov
+ */
+ min_cov = dccp_sk(sk)->dccps_pcrlen;
+ if (dh->dccph_cscov && (min_cov == 0 || dh->dccph_cscov < min_cov)) {
+ dccp_pr_debug("Packet CsCov %d does not satisfy MinCsCov %d\n",
+ dh->dccph_cscov, min_cov);
+ /* FIXME: "Such packets SHOULD be reported using Data Dropped
+ * options (Section 11.7) with Drop Code 0, Protocol
+ * Constraints." */
+ goto discard_and_relse;
}
if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
goto discard_and_relse;
nf_reset(skb);
- return sk_receive_skb(sk, skb);
+ return sk_receive_skb(sk, skb, 1);
no_dccp_socket:
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
goto discard_it;
/*
* Step 2:
+ * If no socket ...
* Generate Reset(No Connection) unless P.type == Reset
* Drop packet and return
*/
if (dh->dccph_type != DCCP_PKT_RESET) {
DCCP_SKB_CB(skb)->dccpd_reset_code =
DCCP_RESET_CODE_NO_CONNECTION;
- dccp_v4_ctl_send_reset(skb);
+ dccp_v4_ctl_send_reset(sk, skb);
}
discard_it:
- /* Discard frame. */
kfree_skb(skb);
return 0;
discard_and_relse:
sock_put(sk);
goto discard_it;
-
-do_time_wait:
- inet_twsk_put(inet_twsk(sk));
- goto no_dccp_socket;
}
static struct inet_connection_sock_af_ops dccp_ipv4_af_ops = {
@@ -1017,20 +950,6 @@ static int dccp_v4_init_sock(struct sock *sk)
return err;
}
-static void dccp_v4_reqsk_destructor(struct request_sock *req)
-{
- kfree(inet_rsk(req)->opt);
-}
-
-static struct request_sock_ops dccp_request_sock_ops = {
- .family = PF_INET,
- .obj_size = sizeof(struct dccp_request_sock),
- .rtx_syn_ack = dccp_v4_send_response,
- .send_ack = dccp_v4_reqsk_send_ack,
- .destructor = dccp_v4_reqsk_destructor,
- .send_reset = dccp_v4_ctl_send_reset,
-};
-
static struct timewait_sock_ops dccp_timewait_sock_ops = {
.twsk_obj_size = sizeof(struct inet_timewait_sock),
};