[DCCP]: Allow to parse options on Request Sockets

The option parsing code currently only parses on full sk's. This causes a problem for
options sent during the initial handshake (in particular timestamps and feature-negotiation
options). Therefore, this patch extends the option parsing code with an additional argument
for request_socks: if it is non-NULL, options are parsed on the request socket, otherwise
the normal path (parsing on the sk) is used.

Subsequent patches, which implement feature negotiation during connection setup, make use
of this facility.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index c676021603f55b8914c09fd6af67547172e0a411..7214031461d3b190d086dd74dc31fad05de850fb 100644 (file)
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -407,8 +407,6 @@ struct dccp_opt_pend {
 
 extern void dccp_minisock_init(struct dccp_minisock *dmsk);
 
-extern int dccp_parse_options(struct sock *sk, struct sk_buff *skb);
-
 struct dccp_request_sock {
        struct inet_request_sock dreq_inet_rsk;
        __u64                    dreq_iss;
@@ -423,6 +421,9 @@ static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
 
 extern struct inet_timewait_death_row dccp_death_row;
 
+extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
+                             struct sk_buff *skb);
+
 struct dccp_options_received {
        u32     dccpor_ndp; /* only 24 bits */
        u32     dccpor_timestamp;

diff --git a/net/dccp/input.c b/net/dccp/input.c
index dacd4fd3c63cb2a1f63f97917cdbb163d09a9420..08392ed86c25403ea574c1e2b39786b8488e4625 100644 (file)
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -369,7 +369,7 @@ int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
        if (dccp_check_seqno(sk, skb))
                goto discard;
 
-       if (dccp_parse_options(sk, skb))
+       if (dccp_parse_options(sk, NULL, skb))
                goto discard;
 
        if (DCCP_SKB_CB(skb)->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
@@ -427,7 +427,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
                        goto out_invalid_packet;
                }
 
-               if (dccp_parse_options(sk, skb))
+               if (dccp_parse_options(sk, NULL, skb))
                        goto out_invalid_packet;
 
                /* Obtain usec RTT sample from SYN exchange (used by CCID 3) */
@@ -609,7 +609,7 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                /*
                 * Step 8: Process options and mark acknowledgeable
                 */
-               if (dccp_parse_options(sk, skb))
+               if (dccp_parse_options(sk, NULL, skb))
                        goto discard;
 
                if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index db17b83e8d3e85b267ed1bd352338ad64119f9df..02fc91ce2505b1eb1260b5ad2d6c03c3a4876196 100644 (file)
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -600,11 +600,12 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
        if (req == NULL)
                goto drop;
 
-       if (dccp_parse_options(sk, skb))
-               goto drop_and_free;
-
        dccp_reqsk_init(req, skb);
 
+       dreq = dccp_rsk(req);
+       if (dccp_parse_options(sk, dreq, skb))
+               goto drop_and_free;
+
        if (security_inet_conn_request(sk, skb, req))
                goto drop_and_free;
 
@@ -621,7 +622,6 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
         * 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;

diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index a08e2cb119157b023431c1f0d835f4ea17967298..f42b75ce7f5ce3c0065cb6b987f291d8bf32a99e 100644 (file)
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -415,11 +415,12 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
        if (req == NULL)
                goto drop;
 
-       if (dccp_parse_options(sk, skb))
-               goto drop_and_free;
-
        dccp_reqsk_init(req, skb);
 
+       dreq = dccp_rsk(req);
+       if (dccp_parse_options(sk, dreq, skb))
+               goto drop_and_free;
+
        if (security_inet_conn_request(sk, skb, req))
                goto drop_and_free;
 
@@ -449,7 +450,6 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
         *   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_v6_init_sequence(skb);
        dreq->dreq_service = service;

diff --git a/net/dccp/options.c b/net/dccp/options.c
index 523250b45ea5be66220791a0ef72ac75a3ed1356..f496d4dc7efcf760fe1d67f210da4431939643e2 100644 (file)
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -46,7 +46,13 @@ static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
        return value;
 }
 
-int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
+/**
+ * dccp_parse_options  -  Parse DCCP options present in @skb
+ * @sk: client|server|listening dccp socket (when @dreq != NULL)
+ * @dreq: request socket to use during connection setup, or NULL
+ */
+int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
+                      struct sk_buff *skb)
 {
        struct dccp_sock *dp = dccp_sk(sk);
        const struct dccp_hdr *dh = dccp_hdr(skb);
@@ -92,6 +98,20 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                                goto out_invalid_option;
                }
 
+               /*
+                * CCID-Specific Options (from RFC 4340, sec. 10.3):
+                *
+                * Option numbers 128 through 191 are for options sent from the
+                * HC-Sender to the HC-Receiver; option numbers 192 through 255
+                * are for options sent from the HC-Receiver to the HC-Sender.
+                *
+                * CCID-specific options are ignored during connection setup, as
+                * negotiation may still be in progress (see RFC 4340, 10.3).
+                *
+                */
+               if (dreq != NULL && opt >= 128)
+                       goto ignore_option;
+
                switch (opt) {
                case DCCPO_PADDING:
                        break;
@@ -150,6 +170,7 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                        opt_val = get_unaligned((__be32 *)value);
                        opt_recv->dccpor_timestamp = ntohl(opt_val);
 
+                       /* FIXME: if dreq != NULL, don't store this on listening socket */
                        dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
                        dp->dccps_timestamp_time = ktime_get_real();
 
@@ -213,15 +234,6 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                        dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
                                      dccp_role(sk), elapsed_time);
                        break;
-                       /*
-                        * From RFC 4340, sec. 10.3:
-                        *
-                        *      Option numbers 128 through 191 are for
-                        *      options sent from the HC-Sender to the
-                        *      HC-Receiver; option numbers 192 through 255
-                        *      are for options sent from the HC-Receiver to
-                        *      the HC-Sender.
-                        */
                case 128 ... 191: {
                        const u16 idx = value - options;
 
@@ -245,7 +257,7 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                                  "implemented, ignoring", sk, opt, len);
                        break;
                }
-
+ignore_option:
                if (opt != DCCPO_MANDATORY)
                        mandatory = 0;
        }