dccp: Clean up old feature-negotiation infrastructure
Gerrit Renker [Mon, 8 Dec 2008 09:17:32 +0000 (01:17 -0800)]
The code removed by this patch is no longer referenced or used, the added
lines update documentation and copyrights.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dccp/feat.c
net/dccp/feat.h

index b127189..077f78d 100644 (file)
@@ -1,8 +1,12 @@
 /*
  *  net/dccp/feat.c
  *
- *  An implementation of the DCCP protocol
- *  Andrea Bittau <a.bittau@cs.ucl.ac.uk>
+ *  Feature negotiation for the DCCP protocol (RFC 4340, section 6)
+ *
+ *  Copyright (c) 2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>
+ *  Rewrote from scratch, some bits from earlier code by
+ *  Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk>
+ *
  *
  *  ASSUMPTIONS
  *  -----------
  *  as published by the Free Software Foundation; either version
  *  2 of the License, or (at your option) any later version.
  */
-
 #include <linux/module.h>
-
 #include "ccid.h"
 #include "feat.h"
 
-#define DCCP_FEAT_SP_NOAGREE (-123)
-
 /*
  * Feature activation handlers.
  *
@@ -811,51 +811,6 @@ int dccp_feat_server_ccid_dependencies(struct dccp_request_sock *dreq)
        return 0;
 }
 
-static int dccp_feat_update_ccid(struct sock *sk, u8 type, u8 new_ccid_nr)
-{
-       struct dccp_sock *dp = dccp_sk(sk);
-       struct dccp_minisock *dmsk = dccp_msk(sk);
-       /* figure out if we are changing our CCID or the peer's */
-       const int rx = type == DCCPO_CHANGE_R;
-       const u8 ccid_nr = rx ? dmsk->dccpms_rx_ccid : dmsk->dccpms_tx_ccid;
-       struct ccid *new_ccid;
-
-       /* Check if nothing is being changed. */
-       if (ccid_nr == new_ccid_nr)
-               return 0;
-
-       new_ccid = ccid_new(new_ccid_nr, sk, rx, GFP_ATOMIC);
-       if (new_ccid == NULL)
-               return -ENOMEM;
-
-       if (rx) {
-               ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk);
-               dp->dccps_hc_rx_ccid = new_ccid;
-               dmsk->dccpms_rx_ccid = new_ccid_nr;
-       } else {
-               ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
-               dp->dccps_hc_tx_ccid = new_ccid;
-               dmsk->dccpms_tx_ccid = new_ccid_nr;
-       }
-
-       return 0;
-}
-
-static int dccp_feat_update(struct sock *sk, u8 type, u8 feat, u8 val)
-{
-       dccp_feat_debug(type, feat, val);
-
-       switch (feat) {
-       case DCCPF_CCID:
-               return dccp_feat_update_ccid(sk, type, val);
-       default:
-               dccp_pr_debug("UNIMPLEMENTED: %s(%d, ...)\n",
-                             dccp_feat_typename(type), feat);
-               break;
-       }
-       return 0;
-}
-
 /* Select the first entry in @servlist that also occurs in @clilist (6.3.1) */
 static int dccp_feat_preflist_match(u8 *servlist, u8 slen, u8 *clilist, u8 clen)
 {
@@ -925,453 +880,6 @@ static int dccp_feat_reconcile(dccp_feat_val *fv, u8 *arr, u8 len,
        return dccp_feat_prefer(rc, fv->sp.vec, fv->sp.len);
 }
 
-#ifdef __this_is_the_old_framework_and_will_be_removed_later_in_a_subsequent_patch
-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 */
-       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 = &dccp_msk(sk)->dccpms_tx_ccid;
-                       else
-                               res = &dccp_msk(sk)->dccpms_rx_ccid;
-                       break;
-
-               default:
-                       DCCP_BUG("Fell through, feat=%d", opt->dccpop_feat);
-                       /* 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 */
-       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 = NULL;
-               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_minisock *dmsk = dccp_msk(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, &dmsk->dccpms_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_minisock *dmsk = dccp_msk(sk);
-       u8 *copy;
-       int rc;
-
-       /* NN features must be Change L (sec. 6.3.2) */
-       if (type != DCCPO_CHANGE_L) {
-               dccp_pr_debug("received %s for NN feature %d\n",
-                               dccp_feat_typename(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 = kmemdup(val, len, GFP_ATOMIC);
-       if (copy == NULL) {
-               kfree(opt);
-               return -ENOMEM;
-       }
-
-       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_feat_debug(type, feature, *copy);
-
-       list_add_tail(&opt->dccpop_node, &dmsk->dccpms_conf);
-
-       return 0;
-}
-
-static void dccp_feat_empty_confirm(struct dccp_minisock *dmsk,
-                                   u8 type, u8 feature)
-{
-       /* 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;
-       }
-
-       switch (type) {
-       case DCCPO_CHANGE_L:
-               opt->dccpop_type = DCCPO_CONFIRM_R;
-               break;
-       case DCCPO_CHANGE_R:
-               opt->dccpop_type = DCCPO_CONFIRM_L;
-               break;
-       default:
-               DCCP_WARN("invalid type %d\n", type);
-               kfree(opt);
-               return;
-       }
-       opt->dccpop_feat = feature;
-       opt->dccpop_val  = NULL;
-       opt->dccpop_len  = 0;
-
-       /* change feature */
-       dccp_pr_debug("Empty %s(%d)\n", dccp_feat_typename(type), feature);
-
-       list_add_tail(&opt->dccpop_node, &dmsk->dccpms_conf);
-}
-
-static void dccp_feat_flush_confirm(struct sock *sk)
-{
-       struct dccp_minisock *dmsk = dccp_msk(sk);
-       /* Check if there is anything to confirm in the first place */
-       int yes = !list_empty(&dmsk->dccpms_conf);
-
-       if (!yes) {
-               struct dccp_opt_pend *opt;
-
-               list_for_each_entry(opt, &dmsk->dccpms_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;
-
-       /* Ignore Change requests other than during connection setup */
-       if (sk->sk_state != DCCP_LISTEN && sk->sk_state != DCCP_REQUESTING)
-               return 0;
-       dccp_feat_debug(type, feature, *val);
-
-       /* figure out if it's SP or NN feature */
-       switch (feature) {
-       /* deal with SP features */
-       case DCCPF_CCID:
-               /* XXX Obsoleted by next patch
-               rc = dccp_feat_sp(sk, type, feature, val, len); */
-               break;
-
-       /* deal with NN features */
-       case DCCPF_ACK_RATIO:
-               /* XXX Obsoleted by next patch
-               rc = dccp_feat_nn(sk, type, feature, val, len); */
-               break;
-
-       /* XXX implement other features */
-       default:
-               dccp_pr_debug("UNIMPLEMENTED: not handling %s(%d, ...)\n",
-                             dccp_feat_typename(type), feature);
-               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(dccp_msk(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_minisock *dmsk = dccp_msk(sk);
-       int found = 0;
-       int all_confirmed = 1;
-
-       /* Ignore Confirm options other than during connection setup */
-       if (sk->sk_state != DCCP_LISTEN && sk->sk_state != DCCP_REQUESTING)
-               return 0;
-       dccp_feat_debug(type, feature, *val);
-
-       /* locate our change request */
-       switch (type) {
-       case DCCPO_CONFIRM_L: t = DCCPO_CHANGE_R; break;
-       case DCCPO_CONFIRM_R: t = DCCPO_CHANGE_L; break;
-       default:              DCCP_WARN("invalid type %d\n", type);
-                             return 1;
-
-       }
-       /* XXX sanity check feature value */
-
-       list_for_each_entry(opt, &dmsk->dccpms_pending, dccpop_node) {
-               if (!opt->dccpop_conf && opt->dccpop_type == t &&
-                   opt->dccpop_feat == feature) {
-                       found = 1;
-                       dccp_pr_debug("feature %d found\n", opt->dccpop_feat);
-
-                       /* 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);
-
-                       /* XXX check the return value of dccp_feat_update */
-                       break;
-               }
-
-               if (!opt->dccpop_conf)
-                       all_confirmed = 0;
-       }
-
-       if (!found)
-               dccp_pr_debug("%s(%d, ...) never requested\n",
-                             dccp_feat_typename(type), feature);
-       return 0;
-}
-
-EXPORT_SYMBOL_GPL(dccp_feat_confirm_recv);
-#endif /* (later) */
-
-void dccp_feat_clean(struct dccp_minisock *dmsk)
-{
-       struct dccp_opt_pend *opt, *next;
-
-       list_for_each_entry_safe(opt, next, &dmsk->dccpms_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(&dmsk->dccpms_pending);
-
-       list_for_each_entry_safe(opt, next, &dmsk->dccpms_conf, dccpop_node) {
-               BUG_ON(opt == NULL);
-               if (opt->dccpop_val != NULL)
-                       kfree(opt->dccpop_val);
-               kfree(opt);
-       }
-       INIT_LIST_HEAD(&dmsk->dccpms_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_minisock *olddmsk = dccp_msk(oldsk);
-       struct dccp_minisock *newdmsk = dccp_msk(newsk);
-       struct dccp_opt_pend *opt;
-       int rc = 0;
-
-       INIT_LIST_HEAD(&newdmsk->dccpms_pending);
-       INIT_LIST_HEAD(&newdmsk->dccpms_conf);
-
-       list_for_each_entry(opt, &olddmsk->dccpms_pending, dccpop_node) {
-               struct dccp_opt_pend *newopt;
-               /* copy the value of the option */
-               u8 *val = kmemdup(opt->dccpop_val, opt->dccpop_len, GFP_ATOMIC);
-
-               if (val == NULL)
-                       goto out_clean;
-
-               newopt = kmemdup(opt, sizeof(*newopt), GFP_ATOMIC);
-               if (newopt == NULL) {
-                       kfree(val);
-                       goto out_clean;
-               }
-
-               /* insert the option */
-               newopt->dccpop_val = val;
-               list_add_tail(&newopt->dccpop_node, &newdmsk->dccpms_pending);
-
-               /* XXX what happens with backlogs and multiple connections at
-                * once...
-                */
-               /* the master socket no longer needs to worry about confirms */
-               opt->dccpop_sc = NULL; /* 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(newdmsk);
-       rc = -ENOMEM;
-       goto out;
-}
-
-EXPORT_SYMBOL_GPL(dccp_feat_clone);
-
 /**
  * dccp_feat_change_recv  -  Process incoming ChangeL/R options
  * @fn: feature-negotiation list to update
index f749610..9b46e2a 100644 (file)
@@ -3,14 +3,14 @@
 /*
  *  net/dccp/feat.h
  *
- *  An implementation of the DCCP protocol
+ *  Feature negotiation for the DCCP protocol (RFC 4340, section 6)
+ *  Copyright (c) 2008 Gerrit Renker <gerrit@erg.abdn.ac.uk>
  *  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.
+ *  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>
 #include "dccp.h"
 
@@ -118,8 +118,6 @@ extern int  dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local,
 extern int  dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val);
 extern int  dccp_feat_parse_options(struct sock *, struct dccp_request_sock *,
                                    u8 mand, u8 opt, u8 feat, u8 *val, u8 len);
-extern void dccp_feat_clean(struct dccp_minisock *dmsk);
-extern int  dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
 extern int  dccp_feat_clone_list(struct list_head const *, struct list_head *);
 extern int  dccp_feat_init(struct sock *sk);