[DCCP]: Initial feature negotiation implementation
Andrea Bittau [Tue, 21 Mar 2006 01:43:56 +0000 (17:43 -0800)]
Still needs more work, but boots and doesn't crashes, even
does some negotiation!

18:38:52.174934  127.0.0.1.43458 > 127.0.0.1.5001: request <change_l ack_ratio 2, change_r ccid 2, change_l ccid 2>
18:38:52.218526  127.0.0.1.5001 > 127.0.0.1.43458: response <nop, nop, change_l ack_ratio 2, confirm_r ccid 2 2, confirm_l ccid 2 2, confirm_r ack_ratio 2>
18:38:52.185398  127.0.0.1.43458 > 127.0.0.1.5001: <nop, confirm_r ack_ratio 2, ack_vector0 0x00, elapsed_time 212>

:-)

Signed-off-by: Andrea Bittau <a.bittau@cs.ucl.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/dccp.h
net/dccp/Makefile
net/dccp/feat.c [new file with mode: 0644]
net/dccp/feat.h [new file with mode: 0644]
net/dccp/input.c
net/dccp/ipv4.c
net/dccp/minisocks.c
net/dccp/options.c
net/dccp/output.c
net/dccp/proto.c
net/dccp/timer.c

index 268b457..f91c8a6 100644 (file)
@@ -154,6 +154,10 @@ enum {
        DCCPO_MANDATORY = 1,
        DCCPO_MIN_RESERVED = 3,
        DCCPO_MAX_RESERVED = 31,
+       DCCPO_CHANGE_L = 32,
+       DCCPO_CONFIRM_L = 33,
+       DCCPO_CHANGE_R = 34,
+       DCCPO_CONFIRM_R = 35,
        DCCPO_NDP_COUNT = 37,
        DCCPO_ACK_VECTOR_0 = 38,
        DCCPO_ACK_VECTOR_1 = 39,
@@ -168,7 +172,9 @@ enum {
 /* DCCP features */
 enum {
        DCCPF_RESERVED = 0,
+       DCCPF_CCID = 1,
        DCCPF_SEQUENCE_WINDOW = 3,
+       DCCPF_ACK_RATIO = 5,
        DCCPF_SEND_ACK_VECTOR = 6,
        DCCPF_SEND_NDP_COUNT = 7,
        /* 10-127 reserved */
@@ -176,9 +182,18 @@ enum {
        DCCPF_MAX_CCID_SPECIFIC = 255,
 };
 
+/* this structure is argument to DCCP_SOCKOPT_CHANGE_X */
+struct dccp_so_feat {
+       __u8 dccpsf_feat;
+       __u8 *dccpsf_val;
+       __u8 dccpsf_len;
+};
+
 /* DCCP socket options */
 #define DCCP_SOCKOPT_PACKET_SIZE       1
 #define DCCP_SOCKOPT_SERVICE           2
+#define DCCP_SOCKOPT_CHANGE_L          3
+#define DCCP_SOCKOPT_CHANGE_R          4
 #define DCCP_SOCKOPT_CCID_RX_INFO      128
 #define DCCP_SOCKOPT_CCID_TX_INFO      192
 
@@ -314,8 +329,8 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
 
 /* initial values for each feature */
 #define DCCPF_INITIAL_SEQUENCE_WINDOW          100
-/* FIXME: for now we're using CCID 2 (TCP-Like) */
 #define DCCPF_INITIAL_CCID                     2
+#define DCCPF_INITIAL_ACK_RATIO                        2
 #define DCCPF_INITIAL_SEND_ACK_VECTOR          1
 /* FIXME: for now we're default to 1 but it should really be 0 */
 #define DCCPF_INITIAL_SEND_NDP_COUNT           1
@@ -335,6 +350,24 @@ struct dccp_options {
        __u8    dccpo_tx_ccid;
        __u8    dccpo_send_ack_vector;
        __u8    dccpo_send_ndp_count;
+       __u8                    dccpo_ack_ratio;
+       struct list_head        dccpo_pending;
+       struct list_head        dccpo_conf;
+};
+
+struct dccp_opt_conf {
+       __u8                    *dccpoc_val;
+       __u8                    dccpoc_len;
+};
+
+struct dccp_opt_pend {
+       struct list_head        dccpop_node;
+       __u8                    dccpop_type;
+       __u8                    dccpop_feat;
+       __u8                    *dccpop_val;
+       __u8                    dccpop_len;
+       int                     dccpop_conf;
+       struct dccp_opt_conf    *dccpop_sc;
 };
 
 extern void __dccp_options_init(struct dccp_options *dccpo);
index 87b27ff..5736ace 100644 (file)
@@ -4,7 +4,7 @@ dccp_ipv6-y := ipv6.o
 
 obj-$(CONFIG_IP_DCCP) += dccp.o
 
-dccp-y := ccid.o input.o ipv4.o minisocks.o options.o output.o proto.o \
+dccp-y := ccid.o feat.o input.o ipv4.o minisocks.o options.o output.o proto.o \
          timer.o
 
 dccp-$(CONFIG_IP_DCCP_ACKVEC) += ackvec.o
diff --git a/net/dccp/feat.c b/net/dccp/feat.c
new file mode 100644 (file)
index 0000000..99d7b7f
--- /dev/null
@@ -0,0 +1,554 @@
+/*
+ *  net/dccp/feat.c
+ *
+ *  An implementation of the DCCP protocol
+ *  Andrea Bittau <a.bittau@cs.ucl.ac.uk>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include "dccp.h"
+#include "feat.h"
+
+#define DCCP_FEAT_SP_NOAGREE (-123)
+
+int dccp_feat_change(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len,
+                    gfp_t gfp)
+{
+       struct dccp_sock *dp = dccp_sk(sk);
+       struct dccp_opt_pend *opt;
+
+       dccp_pr_debug("feat change type=%d feat=%d\n", type, feature);
+
+       /* check if that feature is already being negotiated */
+       list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
+                           dccpop_node) {
+               /* ok we found a negotiation for this option already */
+               if (opt->dccpop_feat == feature && opt->dccpop_type == type) {
+                       dccp_pr_debug("Replacing old\n");
+                       /* replace */
+                       BUG_ON(opt->dccpop_val == NULL);
+                       kfree(opt->dccpop_val);
+                       opt->dccpop_val  = val;
+                       opt->dccpop_len  = len;
+                       opt->dccpop_conf = 0;
+                       return 0;
+               }
+       }
+
+       /* negotiation for a new feature */
+       opt = kmalloc(sizeof(*opt), gfp);
+       if (opt == NULL)
+               return -ENOMEM;
+
+       opt->dccpop_type = type;
+       opt->dccpop_feat = feature;
+       opt->dccpop_len  = len;
+       opt->dccpop_val  = val;
+       opt->dccpop_conf = 0;
+       opt->dccpop_sc   = NULL;
+
+       BUG_ON(opt->dccpop_val == NULL);
+
+       list_add_tail(&opt->dccpop_node, &dp->dccps_options.dccpo_pending);
+       return 0;
+}
+
+EXPORT_SYMBOL_GPL(dccp_feat_change);
+
+/* XXX taking only u8 vals */
+static int dccp_feat_update(struct sock *sk, u8 type, u8 feat, u8 val)
+{
+       /* FIXME implement */
+       dccp_pr_debug("changing [%d] feat %d to %d\n", type, feat, val);
+       return 0;
+}
+
+static int dccp_feat_reconcile(struct sock *sk, struct dccp_opt_pend *opt,
+                              u8 *rpref, u8 rlen)
+{
+       struct dccp_sock *dp = dccp_sk(sk);
+       u8 *spref, slen, *res = NULL;
+       int i, j, rc, agree = 1;
+
+       BUG_ON(rpref == NULL);
+
+       /* check if we are the black sheep */
+       if (dp->dccps_role == DCCP_ROLE_CLIENT) {
+               spref = rpref;
+               slen  = rlen;
+               rpref = opt->dccpop_val;
+               rlen  = opt->dccpop_len;
+       } else {
+               spref = opt->dccpop_val;
+               slen  = opt->dccpop_len;
+       }
+       /*
+        * Now we have server preference list in spref and client preference in
+        * rpref
+        */
+       BUG_ON(spref == NULL);
+       BUG_ON(rpref == NULL);
+
+       /* FIXME sanity check vals */
+
+       /* Are values in any order?  XXX Lame "algorithm" here */
+       /* XXX assume values are 1 byte */
+       for (i = 0; i < slen; i++) {
+               for (j = 0; j < rlen; j++) {
+                       if (spref[i] == rpref[j]) {
+                               res = &spref[i];
+                               break;
+                       }
+               }
+               if (res)
+                       break;
+       }
+
+       /* we didn't agree on anything */
+       if (res == NULL) {
+               /* confirm previous value */
+               switch (opt->dccpop_feat) {
+               case DCCPF_CCID:
+                       /* XXX did i get this right? =P */
+                       if (opt->dccpop_type == DCCPO_CHANGE_L)
+                               res = &dp->dccps_options.dccpo_tx_ccid;
+                       else
+                               res = &dp->dccps_options.dccpo_rx_ccid;
+                       break;
+
+               default:
+                       WARN_ON(1); /* XXX implement res */
+                       return -EFAULT;
+               }
+
+               dccp_pr_debug("Don't agree... reconfirming %d\n", *res);
+               agree = 0; /* this is used for mandatory options... */
+       }
+
+       /* need to put result and our preference list */
+       /* XXX assume 1 byte vals */
+       rlen = 1 + opt->dccpop_len;
+       rpref = kmalloc(rlen, GFP_ATOMIC);
+       if (rpref == NULL)
+               return -ENOMEM;
+
+       *rpref = *res;
+       memcpy(&rpref[1], opt->dccpop_val, opt->dccpop_len);
+
+       /* put it in the "confirm queue" */
+       if (opt->dccpop_sc == NULL) {
+               opt->dccpop_sc = kmalloc(sizeof(*opt->dccpop_sc), GFP_ATOMIC);
+               if (opt->dccpop_sc == NULL) {
+                       kfree(rpref);
+                       return -ENOMEM;
+               }
+       } else {
+               /* recycle the confirm slot */
+               BUG_ON(opt->dccpop_sc->dccpoc_val == NULL);
+               kfree(opt->dccpop_sc->dccpoc_val);
+               dccp_pr_debug("recycling confirm slot\n");
+       }
+       memset(opt->dccpop_sc, 0, sizeof(*opt->dccpop_sc));
+
+       opt->dccpop_sc->dccpoc_val = rpref;
+       opt->dccpop_sc->dccpoc_len = rlen;
+
+       /* update the option on our side [we are about to send the confirm] */
+       rc = dccp_feat_update(sk, opt->dccpop_type, opt->dccpop_feat, *res);
+       if (rc) {
+               kfree(opt->dccpop_sc->dccpoc_val);
+               kfree(opt->dccpop_sc);
+               opt->dccpop_sc = 0;
+               return rc;
+       }
+
+       dccp_pr_debug("Will confirm %d\n", *rpref);
+
+       /* say we want to change to X but we just got a confirm X, suppress our
+        * change
+        */
+       if (!opt->dccpop_conf) {
+               if (*opt->dccpop_val == *res)
+                       opt->dccpop_conf = 1;
+               dccp_pr_debug("won't ask for change of same feature\n");
+       }
+
+       return agree ? 0 : DCCP_FEAT_SP_NOAGREE; /* used for mandatory opts */
+}
+
+static int dccp_feat_sp(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
+{
+       struct dccp_sock *dp = dccp_sk(sk);
+       struct dccp_opt_pend *opt;
+       int rc = 1;
+       u8 t;
+
+       /*
+        * We received a CHANGE.  We gotta match it against our own preference
+        * list.  If we got a CHANGE_R it means it's a change for us, so we need
+        * to compare our CHANGE_L list.
+        */
+       if (type == DCCPO_CHANGE_L)
+               t = DCCPO_CHANGE_R;
+       else
+               t = DCCPO_CHANGE_L;
+
+       /* find our preference list for this feature */
+       list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
+                           dccpop_node) {
+               if (opt->dccpop_type != t || opt->dccpop_feat != feature)
+                       continue;
+
+               /* find the winner from the two preference lists */
+               rc = dccp_feat_reconcile(sk, opt, val, len);
+               break;
+       }
+
+       /* We didn't deal with the change.  This can happen if we have no
+        * preference list for the feature.  In fact, it just shouldn't
+        * happen---if we understand a feature, we should have a preference list
+        * with at least the default value.
+        */
+       BUG_ON(rc == 1);
+
+       return rc;
+}
+
+static int dccp_feat_nn(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
+{
+       struct dccp_opt_pend *opt;
+       struct dccp_sock *dp = dccp_sk(sk);
+       u8 *copy;
+       int rc;
+
+       /* NN features must be change L */
+       if (type == DCCPO_CHANGE_R) {
+               dccp_pr_debug("received CHANGE_R %d for NN feat %d\n",
+                             type, feature);
+               return -EFAULT;
+       }
+
+       /* XXX sanity check opt val */
+
+       /* copy option so we can confirm it */
+       opt = kzalloc(sizeof(*opt), GFP_ATOMIC);
+       if (opt == NULL)
+               return -ENOMEM;
+
+       copy = kmalloc(len, GFP_ATOMIC);
+       if (copy == NULL) {
+               kfree(opt);
+               return -ENOMEM;
+       }
+       memcpy(copy, val, len);
+
+       opt->dccpop_type = DCCPO_CONFIRM_R; /* NN can only confirm R */
+       opt->dccpop_feat = feature;
+       opt->dccpop_val  = copy;
+       opt->dccpop_len  = len;
+
+       /* change feature */
+       rc = dccp_feat_update(sk, type, feature, *val);
+       if (rc) {
+               kfree(opt->dccpop_val);
+               kfree(opt);
+               return rc;
+       }
+
+       dccp_pr_debug("Confirming NN feature %d (val=%d)\n", feature, *copy);
+       list_add_tail(&opt->dccpop_node, &dp->dccps_options.dccpo_conf);
+
+       return 0;
+}
+
+static void dccp_feat_empty_confirm(struct sock *sk, u8 type, u8 feature)
+{
+       struct dccp_sock *dp = dccp_sk(sk);
+       /* XXX check if other confirms for that are queued and recycle slot */
+       struct dccp_opt_pend *opt = kzalloc(sizeof(*opt), GFP_ATOMIC);
+
+       if (opt == NULL) {
+               /* XXX what do we do?  Ignoring should be fine.  It's a change
+                * after all =P
+                */
+               return;
+       }
+
+       opt->dccpop_type = type == DCCPO_CHANGE_L ? DCCPO_CONFIRM_R :
+                                                   DCCPO_CONFIRM_L;
+       opt->dccpop_feat = feature;
+       opt->dccpop_val  = 0;
+       opt->dccpop_len  = 0;
+
+       /* change feature */
+       dccp_pr_debug("Empty confirm feature %d type %d\n", feature, type);
+       list_add_tail(&opt->dccpop_node, &dp->dccps_options.dccpo_conf);
+}
+
+static void dccp_feat_flush_confirm(struct sock *sk)
+{
+       struct dccp_sock *dp = dccp_sk(sk);
+       /* Check if there is anything to confirm in the first place */
+       int yes = !list_empty(&dp->dccps_options.dccpo_conf);
+
+       if (!yes) {
+               struct dccp_opt_pend *opt;
+
+               list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
+                                   dccpop_node) {
+                       if (opt->dccpop_conf) {
+                               yes = 1;
+                               break;
+                       }
+               }
+       }
+
+       if (!yes)
+               return;
+
+       /* OK there is something to confirm... */
+       /* XXX check if packet is in flight?  Send delayed ack?? */
+       if (sk->sk_state == DCCP_OPEN)
+               dccp_send_ack(sk);
+}
+
+int dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature, u8 *val, u8 len)
+{
+       int rc;
+
+       dccp_pr_debug("got feat change type=%d feat=%d\n", type, feature);
+
+       /* figure out if it's SP or NN feature */
+       switch (feature) {
+       /* deal with SP features */
+       case DCCPF_CCID:
+               rc = dccp_feat_sp(sk, type, feature, val, len);
+               break;
+
+       /* deal with NN features */
+       case DCCPF_ACK_RATIO:
+               rc = dccp_feat_nn(sk, type, feature, val, len);
+               break;
+
+       /* XXX implement other features */
+       default:
+               rc = -EFAULT;
+               break;
+       }
+
+       /* check if there were problems changing features */
+       if (rc) {
+               /* If we don't agree on SP, we sent a confirm for old value.
+                * However we propagate rc to caller in case option was
+                * mandatory
+                */
+               if (rc != DCCP_FEAT_SP_NOAGREE)
+                       dccp_feat_empty_confirm(sk, type, feature);
+       }
+
+       /* generate the confirm [if required] */
+       dccp_feat_flush_confirm(sk);
+
+       return rc;
+}
+
+EXPORT_SYMBOL_GPL(dccp_feat_change_recv);
+
+int dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
+                          u8 *val, u8 len)
+{
+       u8 t;
+       struct dccp_opt_pend *opt;
+       struct dccp_sock *dp = dccp_sk(sk);
+       int rc = 1;
+       int all_confirmed = 1;
+
+       dccp_pr_debug("got feat confirm type=%d feat=%d\n", type, feature);
+
+       /* XXX sanity check type & feat */
+
+       /* locate our change request */
+       t = type == DCCPO_CONFIRM_L ? DCCPO_CHANGE_R : DCCPO_CHANGE_L;
+
+       list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
+                           dccpop_node) {
+               if (!opt->dccpop_conf && opt->dccpop_type == t &&
+                   opt->dccpop_feat == feature) {
+                       /* we found it */
+                       /* XXX do sanity check */
+
+                       opt->dccpop_conf = 1;
+
+                       /* We got a confirmation---change the option */
+                       dccp_feat_update(sk, opt->dccpop_type,
+                                        opt->dccpop_feat, *val);
+
+                       dccp_pr_debug("feat %d type %d confirmed %d\n",
+                                     feature, type, *val);
+                       rc = 0;
+                       break;
+               }
+
+               if (!opt->dccpop_conf)
+                       all_confirmed = 0;
+       }
+
+       /* fix re-transmit timer */
+       /* XXX gotta make sure that no option negotiation occurs during
+        * connection shutdown.  Consider that the CLOSEREQ is sent and timer is
+        * on.  if all options are confirmed it might kill timer which should
+        * remain alive until close is received.
+        */
+       if (all_confirmed) {
+               dccp_pr_debug("clear feat negotiation timer %p\n", sk);
+               inet_csk_clear_xmit_timer(sk, ICSK_TIME_RETRANS);
+       }
+
+       if (rc)
+               dccp_pr_debug("feat %d type %d never requested\n",
+                             feature, type);
+       return 0;
+}
+
+EXPORT_SYMBOL_GPL(dccp_feat_confirm_recv);
+
+void dccp_feat_clean(struct sock *sk)
+{
+       struct dccp_sock *dp = dccp_sk(sk);
+       struct dccp_opt_pend *opt, *next;
+
+       list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_pending,
+                                dccpop_node) {
+                BUG_ON(opt->dccpop_val == NULL);
+                kfree(opt->dccpop_val);
+
+               if (opt->dccpop_sc != NULL) {
+                       BUG_ON(opt->dccpop_sc->dccpoc_val == NULL);
+                       kfree(opt->dccpop_sc->dccpoc_val);
+                       kfree(opt->dccpop_sc);
+               }
+
+                kfree(opt);
+        }
+       INIT_LIST_HEAD(&dp->dccps_options.dccpo_pending);
+
+       list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_conf,
+                                dccpop_node) {
+               BUG_ON(opt == NULL);
+               if (opt->dccpop_val != NULL)
+                       kfree(opt->dccpop_val);
+               kfree(opt);
+       }
+       INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
+}
+
+EXPORT_SYMBOL_GPL(dccp_feat_clean);
+
+/* this is to be called only when a listening sock creates its child.  It is
+ * assumed by the function---the confirm is not duplicated, but rather it is
+ * "passed on".
+ */
+int dccp_feat_clone(struct sock *oldsk, struct sock *newsk)
+{
+       struct dccp_sock *olddp = dccp_sk(oldsk);
+       struct dccp_sock *newdp = dccp_sk(newsk);
+       struct dccp_opt_pend *opt;
+       int rc = 0;
+
+       INIT_LIST_HEAD(&newdp->dccps_options.dccpo_pending);
+       INIT_LIST_HEAD(&newdp->dccps_options.dccpo_conf);
+
+       list_for_each_entry(opt, &olddp->dccps_options.dccpo_pending,
+                           dccpop_node) {
+               struct dccp_opt_pend *newopt;
+               /* copy the value of the option */
+               u8 *val = kmalloc(opt->dccpop_len, GFP_ATOMIC);
+
+               if (val == NULL)
+                       goto out_clean;
+               memcpy(val, opt->dccpop_val, opt->dccpop_len);
+
+               newopt = kmalloc(sizeof(*newopt), GFP_ATOMIC);
+               if (newopt == NULL) {
+                       kfree(val);
+                       goto out_clean;
+               }
+
+               /* insert the option */
+               memcpy(newopt, opt, sizeof(*newopt));
+               newopt->dccpop_val = val;
+               list_add_tail(&newopt->dccpop_node,
+                             &newdp->dccps_options.dccpo_pending);
+
+               /* XXX what happens with backlogs and multiple connections at
+                * once...
+                */
+               /* the master socket no longer needs to worry about confirms */
+               opt->dccpop_sc = 0; /* it's not a memleak---new socket has it */
+
+               /* reset state for a new socket */
+               opt->dccpop_conf = 0;
+       }
+
+       /* XXX not doing anything about the conf queue */
+
+out:
+       return rc;
+
+out_clean:
+       dccp_feat_clean(newsk);
+       rc = -ENOMEM;
+       goto out;
+}
+
+EXPORT_SYMBOL_GPL(dccp_feat_clone);
+
+static int __dccp_feat_init(struct sock *sk, u8 type, u8 feat, u8 *val, u8 len)
+{
+       int rc = -ENOMEM;
+       u8 *copy = kmalloc(len, GFP_KERNEL);
+
+       if (copy != NULL) {
+               memcpy(copy, val, len);
+               rc = dccp_feat_change(sk, type, feat, copy, len, GFP_KERNEL);
+               if (rc)
+                       kfree(copy);
+       }
+       return rc;
+}
+
+int dccp_feat_init(struct sock *sk)
+{
+       struct dccp_sock *dp = dccp_sk(sk);
+       int rc;
+
+       INIT_LIST_HEAD(&dp->dccps_options.dccpo_pending);
+       INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
+
+       /* CCID L */
+       rc = __dccp_feat_init(sk, DCCPO_CHANGE_L, DCCPF_CCID,
+                             &dp->dccps_options.dccpo_tx_ccid, 1);
+       if (rc)
+               goto out;
+
+       /* CCID R */
+       rc = __dccp_feat_init(sk, DCCPO_CHANGE_R, DCCPF_CCID,
+                             &dp->dccps_options.dccpo_rx_ccid, 1);
+       if (rc)
+               goto out;
+
+       /* Ack ratio */
+       rc = __dccp_feat_init(sk, DCCPO_CHANGE_L, DCCPF_ACK_RATIO,
+                             &dp->dccps_options.dccpo_ack_ratio, 1);
+out:
+       return rc;
+}
+
+EXPORT_SYMBOL_GPL(dccp_feat_init);
diff --git a/net/dccp/feat.h b/net/dccp/feat.h
new file mode 100644 (file)
index 0000000..67da062
--- /dev/null
@@ -0,0 +1,28 @@
+#ifndef _DCCP_FEAT_H
+#define _DCCP_FEAT_H
+/*
+ *  net/dccp/feat.h
+ *
+ *  An implementation of the DCCP protocol
+ *  Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
+ *
+ *     This program is free software; you can redistribute it and/or modify it
+ *     under the terms of the GNU General Public License version 2 as
+ *     published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+
+struct sock;
+
+extern int  dccp_feat_change(struct sock *sk, u8 type, u8 feature,
+                            u8 *val, u8 len, gfp_t gfp);
+extern int  dccp_feat_change_recv(struct sock *sk, u8 type, u8 feature,
+                                 u8 *val, u8 len);
+extern int  dccp_feat_confirm_recv(struct sock *sk, u8 type, u8 feature,
+                                  u8 *val, u8 len);
+extern void dccp_feat_clean(struct sock *sk);
+extern int  dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
+extern int  dccp_feat_init(struct sock *sk);
+
+#endif /* _DCCP_FEAT_H */
index b6cba72..4b6d43d 100644 (file)
@@ -300,6 +300,9 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
                        goto out_invalid_packet;
                }
 
+               if (dccp_parse_options(sk, skb))
+                       goto out_invalid_packet;
+
                 if (dp->dccps_options.dccpo_send_ack_vector &&
                     dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk,
                                     DCCP_SKB_CB(skb)->dccpd_seq,
index 38321ad..fcfb486 100644 (file)
@@ -28,6 +28,7 @@
 #include "ackvec.h"
 #include "ccid.h"
 #include "dccp.h"
+#include "feat.h"
 
 struct inet_hashinfo __cacheline_aligned dccp_hashinfo = {
        .lhash_lock     = RW_LOCK_UNLOCKED,
@@ -535,7 +536,8 @@ int dccp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
        if (req == NULL)
                goto drop;
 
-       /* FIXME: process options */
+       if (dccp_parse_options(sk, skb))
+               goto drop;
 
        dccp_openreq_init(req, &dp, skb);
 
@@ -1049,6 +1051,8 @@ int dccp_v4_init_sock(struct sock *sk)
         * setsockopt(CCIDs-I-want/accept). -acme
         */
        if (likely(!dccp_ctl_socket_init)) {
+               int rc;
+
                if (dp->dccps_options.dccpo_send_ack_vector) {
                        dp->dccps_hc_rx_ackvec = dccp_ackvec_alloc(GFP_KERNEL);
                        if (dp->dccps_hc_rx_ackvec == NULL)
@@ -1069,8 +1073,16 @@ int dccp_v4_init_sock(struct sock *sk)
                        dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
                        return -ENOMEM;
                }
-       } else
+
+               rc = dccp_feat_init(sk);
+               if (rc)
+                       return rc;
+       } else {
+               /* control socket doesn't need feat nego */
+               INIT_LIST_HEAD(&dp->dccps_options.dccpo_pending);
+               INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
                dccp_ctl_socket_init = 0;
+       }
 
        dccp_init_xmit_timers(sk);
        icsk->icsk_rto = DCCP_TIMEOUT_INIT;
@@ -1118,6 +1130,9 @@ int dccp_v4_destroy_sock(struct sock *sk)
        ccid_exit(dp->dccps_hc_tx_ccid, sk);
        dp->dccps_hc_rx_ccid = dp->dccps_hc_tx_ccid = NULL;
 
+       /* clean up feature negotiation state */
+       dccp_feat_clean(sk);
+
        return 0;
 }
 
index a60a3e9..9e1de59 100644 (file)
@@ -22,6 +22,7 @@
 #include "ackvec.h"
 #include "ccid.h"
 #include "dccp.h"
+#include "feat.h"
 
 struct inet_timewait_death_row dccp_death_row = {
        .sysctl_max_tw_buckets = NR_FILE * 2,
@@ -114,6 +115,9 @@ struct sock *dccp_create_openreq_child(struct sock *sk,
                newicsk->icsk_rto          = DCCP_TIMEOUT_INIT;
                do_gettimeofday(&newdp->dccps_epoch);
 
+               if (dccp_feat_clone(sk, newsk))
+                       goto out_free;
+
                if (newdp->dccps_options.dccpo_send_ack_vector) {
                        newdp->dccps_hc_rx_ackvec =
                                                dccp_ackvec_alloc(GFP_ATOMIC);
index 0a76426..7f99306 100644 (file)
 #include "ackvec.h"
 #include "ccid.h"
 #include "dccp.h"
+#include "feat.h"
 
 /* stores the default values for new connection. may be changed with sysctl */
 static const struct dccp_options dccpo_default_values = {
        .dccpo_sequence_window    = DCCPF_INITIAL_SEQUENCE_WINDOW,
        .dccpo_rx_ccid            = DCCPF_INITIAL_CCID,
        .dccpo_tx_ccid            = DCCPF_INITIAL_CCID,
+       .dccpo_ack_ratio          = DCCPF_INITIAL_ACK_RATIO,
        .dccpo_send_ack_vector    = DCCPF_INITIAL_SEND_ACK_VECTOR,
        .dccpo_send_ndp_count     = DCCPF_INITIAL_SEND_NDP_COUNT,
 };
@@ -69,6 +71,8 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
        unsigned char opt, len;
        unsigned char *value;
        u32 elapsed_time;
+       int rc;
+       int mandatory = 0;
 
        memset(opt_recv, 0, sizeof(*opt_recv));
 
@@ -100,6 +104,11 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                switch (opt) {
                case DCCPO_PADDING:
                        break;
+               case DCCPO_MANDATORY:
+                       if (mandatory)
+                               goto out_invalid_option;
+                       mandatory = 1;
+                       break;
                case DCCPO_NDP_COUNT:
                        if (len > 3)
                                goto out_invalid_option;
@@ -108,6 +117,31 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                        dccp_pr_debug("%sNDP count=%d\n", debug_prefix,
                                      opt_recv->dccpor_ndp);
                        break;
+               case DCCPO_CHANGE_L:
+                       /* fall through */
+               case DCCPO_CHANGE_R:
+                       if (len < 2)
+                               goto out_invalid_option;
+                       rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
+                                                  len - 1);
+                       /*
+                        * When there is a change error, change_recv is
+                        * responsible for dealing with it.  i.e. reply with an
+                        * empty confirm.
+                        * If the change was mandatory, then we need to die.
+                        */
+                       if (rc && mandatory)
+                               goto out_invalid_option;
+                       break;
+               case DCCPO_CONFIRM_L:
+                       /* fall through */
+               case DCCPO_CONFIRM_R:
+                       if (len < 2)
+                               goto out_invalid_option;
+                       if (dccp_feat_confirm_recv(sk, opt, *value,
+                                                  value + 1, len - 1))
+                               goto out_invalid_option;
+                       break;
                case DCCPO_ACK_VECTOR_0:
                case DCCPO_ACK_VECTOR_1:
                        if (pkt_type == DCCP_PKT_DATA)
@@ -208,6 +242,9 @@ int dccp_parse_options(struct sock *sk, struct sk_buff *skb)
                                sk, opt, len);
                        break;
                }
+
+               if (opt != DCCPO_MANDATORY)
+                       mandatory = 0;
        }
 
        return 0;
@@ -356,7 +393,7 @@ void dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
 {
        struct timeval tv;
        u32 now;
-       
+
        dccp_timestamp(sk, &tv);
        now = timeval_usecs(&tv) / 10;
        /* yes this will overflow but that is the point as we want a
@@ -402,7 +439,7 @@ static void dccp_insert_option_timestamp_echo(struct sock *sk,
        tstamp_echo = htonl(dp->dccps_timestamp_echo);
        memcpy(to, &tstamp_echo, 4);
        to += 4;
-       
+
        if (elapsed_time_len == 2) {
                const u16 var16 = htons((u16)elapsed_time);
                memcpy(to, &var16, 2);
@@ -421,6 +458,93 @@ static void dccp_insert_option_timestamp_echo(struct sock *sk,
        dp->dccps_timestamp_time.tv_usec = 0;
 }
 
+static int dccp_insert_feat_opt(struct sk_buff *skb, u8 type, u8 feat,
+                               u8 *val, u8 len)
+{
+       u8 *to;
+
+       if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 3 > DCCP_MAX_OPT_LEN) {
+               LIMIT_NETDEBUG(KERN_INFO "DCCP: packet too small"
+                              " to insert feature %d option!\n", feat);
+               return -1;
+       }
+
+       DCCP_SKB_CB(skb)->dccpd_opt_len += len + 3;
+
+       to    = skb_push(skb, len + 3);
+       *to++ = type;
+       *to++ = len + 3;
+       *to++ = feat;
+
+       if (len)
+               memcpy(to, val, len);
+       dccp_pr_debug("option %d feat %d len %d\n", type, feat, len);
+
+       return 0;
+}
+
+static void dccp_insert_feat(struct sock *sk, struct sk_buff *skb)
+{
+       struct dccp_sock *dp = dccp_sk(sk);
+       struct dccp_opt_pend *opt, *next;
+       int change = 0;
+
+       /* confirm any options [NN opts] */
+       list_for_each_entry_safe(opt, next, &dp->dccps_options.dccpo_conf,
+                                dccpop_node) {
+               dccp_insert_feat_opt(skb, opt->dccpop_type,
+                                    opt->dccpop_feat, opt->dccpop_val,
+                                    opt->dccpop_len);
+               /* fear empty confirms */
+               if (opt->dccpop_val)
+                       kfree(opt->dccpop_val);
+               kfree(opt);
+       }
+       INIT_LIST_HEAD(&dp->dccps_options.dccpo_conf);
+
+       /* see which features we need to send */
+       list_for_each_entry(opt, &dp->dccps_options.dccpo_pending,
+                           dccpop_node) {
+               /* see if we need to send any confirm */
+               if (opt->dccpop_sc) {
+                       dccp_insert_feat_opt(skb, opt->dccpop_type + 1,
+                                            opt->dccpop_feat,
+                                            opt->dccpop_sc->dccpoc_val,
+                                            opt->dccpop_sc->dccpoc_len);
+
+                       BUG_ON(!opt->dccpop_sc->dccpoc_val);
+                       kfree(opt->dccpop_sc->dccpoc_val);
+                       kfree(opt->dccpop_sc);
+                       opt->dccpop_sc = NULL;
+               }
+
+               /* any option not confirmed, re-send it */
+               if (!opt->dccpop_conf) {
+                       dccp_insert_feat_opt(skb, opt->dccpop_type,
+                                            opt->dccpop_feat, opt->dccpop_val,
+                                            opt->dccpop_len);
+                       change++;
+               }
+       }
+
+       /* Retransmit timer.
+        * If this is the master listening sock, we don't set a timer on it.  It
+        * should be fine because if the dude doesn't receive our RESPONSE
+        * [which will contain the CHANGE] he will send another REQUEST which
+        * will "retrnasmit" the change.
+        */
+       if (change && dp->dccps_role != DCCP_ROLE_LISTEN) {
+               dccp_pr_debug("reset feat negotiation timer %p\n", sk);
+
+               /* XXX don't reset the timer on re-transmissions.  I.e. reset it
+                * only when sending new stuff i guess.  Currently the timer
+                * never backs off because on re-transmission it just resets it!
+                */
+               inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
+                                         inet_csk(sk)->icsk_rto, DCCP_RTO_MAX);
+       }
+}
+
 void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
 {
        struct dccp_sock *dp = dccp_sk(sk);
@@ -447,6 +571,17 @@ void dccp_insert_options(struct sock *sk, struct sk_buff *skb)
                dp->dccps_hc_tx_insert_options = 0;
        }
 
+       /* Feature negotiation */
+       switch(DCCP_SKB_CB(skb)->dccpd_type) {
+               /* Data packets can't do feat negotiation */
+       case DCCP_PKT_DATA:
+       case DCCP_PKT_DATAACK:
+               break;
+       default:
+               dccp_insert_feat(sk, skb);
+               break;
+       }
+
        /* XXX: insert other options when appropriate */
 
        if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) {
index efd7ffb..0cc2bcf 100644 (file)
@@ -64,6 +64,10 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
                case DCCP_PKT_DATAACK:
                        break;
 
+               case DCCP_PKT_REQUEST:
+                       set_ack = 0;
+                       /* fall through */
+
                case DCCP_PKT_SYNC:
                case DCCP_PKT_SYNCACK:
                        ackno = dcb->dccpd_seq;
index 81ad249..1a8cf8e 100644 (file)
@@ -37,6 +37,7 @@
 
 #include "ccid.h"
 #include "dccp.h"
+#include "feat.h"
 
 DEFINE_SNMP_STAT(struct dccp_mib, dccp_statistics) __read_mostly;
 
@@ -255,6 +256,39 @@ static int dccp_setsockopt_service(struct sock *sk, const u32 service,
        return 0;
 }
 
+/* byte 1 is feature.  the rest is the preference list */
+static int dccp_setsockopt_change(struct sock *sk, int type,
+                                 struct dccp_so_feat __user *optval)
+{
+       struct dccp_so_feat opt;
+       u8 *val;
+       int rc;
+
+       if (copy_from_user(&opt, optval, sizeof(opt)))
+               return -EFAULT;
+
+       val = kmalloc(opt.dccpsf_len, GFP_KERNEL);
+       if (!val)
+               return -ENOMEM;
+
+       if (copy_from_user(val, opt.dccpsf_val, opt.dccpsf_len)) {
+               rc = -EFAULT;
+               goto out_free_val;
+       }
+
+       rc = dccp_feat_change(sk, type, opt.dccpsf_feat, val, opt.dccpsf_len,
+                             GFP_KERNEL);
+       if (rc)
+               goto out_free_val;
+
+out:
+       return rc;
+
+out_free_val:
+       kfree(val);
+       goto out;
+}
+
 int dccp_setsockopt(struct sock *sk, int level, int optname,
                    char __user *optval, int optlen)
 {
@@ -284,6 +318,25 @@ int dccp_setsockopt(struct sock *sk, int level, int optname,
        case DCCP_SOCKOPT_PACKET_SIZE:
                dp->dccps_packet_size = val;
                break;
+
+       case DCCP_SOCKOPT_CHANGE_L:
+               if (optlen != sizeof(struct dccp_so_feat))
+                       err = -EINVAL;
+               else
+                       err = dccp_setsockopt_change(sk, DCCPO_CHANGE_L,
+                                                    (struct dccp_so_feat *)
+                                                    optval);
+               break;
+
+       case DCCP_SOCKOPT_CHANGE_R:
+               if (optlen != sizeof(struct dccp_so_feat))
+                       err = -EINVAL;
+               else
+                       err = dccp_setsockopt_change(sk, DCCPO_CHANGE_R,
+                                                    (struct dccp_so_feat *)
+                                                    optval);
+               break;
+
        default:
                err = -ENOPROTOOPT;
                break;
index aa34b57..d7c7866 100644 (file)
@@ -141,6 +141,17 @@ static void dccp_retransmit_timer(struct sock *sk)
 {
        struct inet_connection_sock *icsk = inet_csk(sk);
 
+       /* retransmit timer is used for feature negotiation throughout
+        * connection.  In this case, no packet is re-transmitted, but rather an
+        * ack is generated and pending changes are splaced into its options.
+        */
+       if (sk->sk_send_head == NULL) {
+               dccp_pr_debug("feat negotiation retransmit timeout %p\n", sk);
+               if (sk->sk_state == DCCP_OPEN)
+                       dccp_send_ack(sk);
+               goto backoff;
+       }
+
        /*
         * sk->sk_send_head has to have one skb with
         * DCCP_SKB_CB(skb)->dccpd_type set to one of the retransmittable DCCP
@@ -177,6 +188,7 @@ static void dccp_retransmit_timer(struct sock *sk)
                goto out;
        }
 
+backoff:
        icsk->icsk_backoff++;
        icsk->icsk_retransmits++;