[DCCP]: Miscellaneous code tidy-ups

This patch does not change code; it performs some trivial clean/tidy-ups:

  * removal of a `debug_prefix' string in favour of the
    already existing dccp_role(sk)

  * add documentation of structures and constants

  * separated out the cases for invalid packets (step 1
    of the packet validation)

  * removing duplicate statements

  * combining declaration & initialisation

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index 696319e..d308f12 100644 (file)
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -209,6 +209,7 @@ struct dccp_so_feat {
 #define DCCP_SOCKOPT_CCID_RX_INFO      128
 #define DCCP_SOCKOPT_CCID_TX_INFO      192
 
+/* maximum number of services provided on the same listening port */
 #define DCCP_SERVICE_LIST_MAX_LEN      32
 
 #ifdef __KERNEL__
@@ -355,6 +356,9 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
   * @dccpms_ccid - Congestion Control Id (CCID) (section 10)
   * @dccpms_send_ack_vector - Send Ack Vector Feature (section 11.5)
   * @dccpms_send_ndp_count - Send NDP Count Feature (7.7.2)
+  * @dccpms_ack_ratio - Ack Ratio Feature (section 11.3)
+  * @dccpms_pending - List of features being negotiated
+  * @dccpms_conf -
   */
 struct dccp_minisock {
        __u64                   dccpms_sequence_window;
@@ -452,14 +456,26 @@ struct dccp_ackvec;
  * @dccps_gss - greatest sequence number sent
  * @dccps_gsr - greatest valid sequence number received
  * @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
+ * @dccps_service - first (passive sock) or unique (active sock) service code
+ * @dccps_service_list - second .. last service code on passive socket
  * @dccps_timestamp_time - time of latest TIMESTAMP option
  * @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
  * @dccps_packet_size - Set thru setsockopt
- * @dccps_role - Role of this sock, one of %dccp_role
+ * @dccps_l_ack_ratio -
+ * @dccps_r_ack_ratio -
  * @dccps_pcslen - sender   partial checksum coverage (via sockopt)
  * @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
  * @dccps_ndp_count - number of Non Data Packets since last data packet
+ * @dccps_mss_cache -
+ * @dccps_minisock -
  * @dccps_hc_rx_ackvec - rx half connection ack vector
+ * @dccps_hc_rx_ccid -
+ * @dccps_hc_tx_ccid -
+ * @dccps_options_received -
+ * @dccps_epoch -
+ * @dccps_role - Role of this sock, one of %dccp_role
+ * @dccps_hc_rx_insert_options -
+ * @dccps_hc_tx_insert_options -
  * @dccps_xmit_timer - timer for when CCID is not ready to send
  */
 struct dccp_sock {

diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c
index f820887..0c54b89 100644 (file)
--- a/net/dccp/ackvec.c
+++ b/net/dccp/ackvec.c
@@ -67,10 +67,6 @@ static void dccp_ackvec_insert_avr(struct dccp_ackvec *av,
 int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
 {
        struct dccp_sock *dp = dccp_sk(sk);
-#ifdef CONFIG_IP_DCCP_DEBUG
-       const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
-                               "CLIENT tx: " : "server tx: ";
-#endif
        struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
        int len = av->dccpav_vec_len + 2;
        struct timeval now;
@@ -129,9 +125,9 @@ int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
 
        dccp_ackvec_insert_avr(av, avr);
 
-       dccp_pr_debug("%sACK Vector 0, len=%d, ack_seqno=%llu, "
+       dccp_pr_debug("%s ACK Vector 0, len=%d, ack_seqno=%llu, "
                      "ack_ackno=%llu\n",
-                     debug_prefix, avr->dccpavr_sent_len,
+                     dccp_role(sk), avr->dccpavr_sent_len,
                      (unsigned long long)avr->dccpavr_ack_seqno,
                      (unsigned long long)avr->dccpavr_ack_ackno);
        return 0;
@@ -380,14 +376,9 @@ void dccp_ackvec_check_rcv_ackno(struct dccp_ackvec *av, struct sock *sk,
         */
        list_for_each_entry_reverse(avr, &av->dccpav_records, dccpavr_node) {
                if (ackno == avr->dccpavr_ack_seqno) {
-#ifdef CONFIG_IP_DCCP_DEBUG
-                       struct dccp_sock *dp = dccp_sk(sk);
-                       const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
-                                               "CLIENT rx ack: " : "server rx ack: ";
-#endif
-                       dccp_pr_debug("%sACK packet 0, len=%d, ack_seqno=%llu, "
+                       dccp_pr_debug("%s ACK packet 0, len=%d, ack_seqno=%llu, "
                                      "ack_ackno=%llu, ACKED!\n",
-                                     debug_prefix, 1,
+                                     dccp_role(sk), 1,
                                      (unsigned long long)avr->dccpavr_ack_seqno,
                                      (unsigned long long)avr->dccpavr_ack_ackno);
                        dccp_ackvec_throw_record(av, avr);
@@ -437,16 +428,10 @@ found:
                if (between48(avr->dccpavr_ack_seqno, ackno_end_rl, ackno)) {
                        const u8 state = *vector & DCCP_ACKVEC_STATE_MASK;
                        if (state != DCCP_ACKVEC_STATE_NOT_RECEIVED) {
-#ifdef CONFIG_IP_DCCP_DEBUG
-                               struct dccp_sock *dp = dccp_sk(sk);
-                               const char *debug_prefix =
-                                       dp->dccps_role == DCCP_ROLE_CLIENT ?
-                                       "CLIENT rx ack: " : "server rx ack: ";
-#endif
-                               dccp_pr_debug("%sACK vector 0, len=%d, "
+                               dccp_pr_debug("%s ACK vector 0, len=%d, "
                                              "ack_seqno=%llu, ack_ackno=%llu, "
                                              "ACKED!\n",
-                                             debug_prefix, len,
+                                             dccp_role(sk), len,
                                              (unsigned long long)
                                              avr->dccpavr_ack_seqno,
                                              (unsigned long long)

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index 61c0901..34d6d19 100644 (file)
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -518,7 +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)
@@ -552,13 +552,11 @@ 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);
 
        dccp_csum_outgoing(skb);
        dh->dccph_checksum = dccp_v4_csum_finish(skb, rxskb->nh.iph->saddr,
@@ -734,6 +732,11 @@ 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;
@@ -742,6 +745,7 @@ int dccp_invalid_packet(struct sk_buff *skb)
        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");
                return 1;
@@ -749,42 +753,37 @@ int dccp_invalid_packet(struct sk_buff *skb)
 
        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");
                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);
+                                           "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);
+                                           "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",
+       if (dh->dccph_type >= DCCP_PKT_DATA    &&
+           dh->dccph_type <= DCCP_PKT_DATAACK && dh->dccph_x == 0)  {
+               LIMIT_NETDEBUG(KERN_WARNING "DCCP: P.type (%s) not Data||Ack||"
+                                           "DataAck, while P.X == 0\n",
                               dccp_packet_name(dh->dccph_type));
                return 1;
        }

diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 2165b17..fc32617 100644 (file)
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -318,7 +318,7 @@ static void dccp_v6_ctl_send_reset(struct sk_buff *rxskb)
                                       sizeof(struct dccp_hdr_reset);
        struct sk_buff *skb;
        struct flowi fl;
-       u64 seqno;
+       u64 seqno = 0;
 
        if (rxdh->dccph_type == DCCP_PKT_RESET)
                return;
@@ -345,13 +345,11 @@ static void dccp_v6_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);
 
        dccp_csum_outgoing(skb);
        dh->dccph_checksum = dccp_v6_csum_finish(skb, &rxskb->nh.ipv6h->saddr,

diff --git a/net/dccp/options.c b/net/dccp/options.c
index 2d0ef27..7e50678 100644 (file)
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -60,10 +60,6 @@ static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len)
 int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
 {
        struct dccp_sock *dp = dccp_sk(sk);
-#ifdef CONFIG_IP_DCCP_DEBUG
-       const char *debug_prefix = dp->dccps_role == DCCP_ROLE_CLIENT ?
-                                       "CLIENT rx opt: " : "server rx opt: ";
-#endif
        const struct dccp_hdr *dh = dccp_hdr(skb);
        const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
        unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
@@ -119,7 +115,7 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                                goto out_invalid_option;
 
                        opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
-                       dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
+                       dccp_pr_debug("%s rx opt: NDP count=%d\n", dccp_role(sk),
                                      opt_recv->dccpor_ndp);
                        break;
                case DCCPO_CHANGE_L:
@@ -165,8 +161,8 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                        dp->dccps_timestamp_echo = opt_recv->dccpor_timestamp;
                        dccp_timestamp(sk, &dp->dccps_timestamp_time);
 
-                       dccp_pr_debug("%sTIMESTAMP=%u, ackno=%llu\n",
-                                     debug_prefix, opt_recv->dccpor_timestamp,
+                       dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
+                                     dccp_role(sk), opt_recv->dccpor_timestamp,
                                      (unsigned long long)
                                      DCCP_SKB_CB(skb)->dccpd_ack_seq);
                        break;
@@ -176,8 +172,8 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
 
                        opt_recv->dccpor_timestamp_echo = ntohl(*(__be32 *)value);
 
-                       dccp_pr_debug("%sTIMESTAMP_ECHO=%u, len=%d, ackno=%llu, ",
-                                     debug_prefix,
+                       dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
+                                     "ackno=%llu, ",  dccp_role(sk),
                                      opt_recv->dccpor_timestamp_echo,
                                      len + 2,
                                      (unsigned long long)
@@ -211,8 +207,8 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                        if (elapsed_time > opt_recv->dccpor_elapsed_time)
                                opt_recv->dccpor_elapsed_time = elapsed_time;
 
-                       dccp_pr_debug("%sELAPSED_TIME=%d\n", debug_prefix,
-                                     elapsed_time);
+                       dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
+                                     dccp_role(sk), elapsed_time);
                        break;
                        /*
                         * From RFC 4340, sec. 10.3:

diff --git a/net/dccp/output.c b/net/dccp/output.c
index ef22f3c..c34eada 100644 (file)
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -333,6 +333,7 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
                return NULL;
        }
 
+       /* Build and checksum header */
        dh = dccp_zeroed_hdr(skb, dccp_header_size);
 
        dh->dccph_sport = inet_sk(sk)->sport;

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 9c9c08c..0225bda 100644 (file)
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -452,9 +452,8 @@ out_free_val:
 static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
                char __user *optval, int optlen)
 {
-       struct dccp_sock *dp;
-       int err;
-       int val;
+       struct dccp_sock *dp = dccp_sk(sk);
+       int val, err = 0;
 
        if (optlen < sizeof(int))
                return -EINVAL;
@@ -466,9 +465,6 @@ static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
                return dccp_setsockopt_service(sk, val, optval, optlen);
 
        lock_sock(sk);
-       dp = dccp_sk(sk);
-       err = 0;
-
        switch (optname) {
        case DCCP_SOCKOPT_PACKET_SIZE:
                dp->dccps_packet_size = val;