dccp: Set per-connection CCIDs via socket options
With this patch, TX/RX CCIDs can now be changed on a per-connection
basis, which overrides the defaults set by the global sysctl variables
for TX/RX CCIDs.
To make full use of this facility, the remaining patches of this patch
set are needed, which track dependencies and activate negotiated
feature values.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c
index 1e8be24..01e4d39 100644
--- a/net/dccp/ackvec.c
+++ b/net/dccp/ackvec.c
@@ -12,7 +12,6 @@
#include "ackvec.h"
#include "dccp.h"
-#include <linux/dccp.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/kernel.h>
@@ -68,7 +67,7 @@
struct dccp_sock *dp = dccp_sk(sk);
struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
/* Figure out how many options do we need to represent the ackvec */
- const u16 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_MAX_ACKVEC_OPT_LEN);
+ const u8 nr_opts = DIV_ROUND_UP(av->av_vec_len, DCCP_SINGLE_OPT_MAXLEN);
u16 len = av->av_vec_len + 2 * nr_opts, i;
u32 elapsed_time;
const unsigned char *tail, *from;
@@ -100,8 +99,8 @@
for (i = 0; i < nr_opts; ++i) {
int copylen = len;
- if (len > DCCP_MAX_ACKVEC_OPT_LEN)
- copylen = DCCP_MAX_ACKVEC_OPT_LEN;
+ if (len > DCCP_SINGLE_OPT_MAXLEN)
+ copylen = DCCP_SINGLE_OPT_MAXLEN;
*to++ = DCCPO_ACK_VECTOR_0;
*to++ = copylen + 2;
@@ -432,7 +431,7 @@
int dccp_ackvec_parse(struct sock *sk, const struct sk_buff *skb,
u64 *ackno, const u8 opt, const u8 *value, const u8 len)
{
- if (len > DCCP_MAX_ACKVEC_OPT_LEN)
+ if (len > DCCP_SINGLE_OPT_MAXLEN)
return -1;
/* dccp_ackvector_print(DCCP_SKB_CB(skb)->dccpd_ack_seq, value, len); */
diff --git a/net/dccp/ackvec.h b/net/dccp/ackvec.h
index bcb64fb..4ccee03 100644
--- a/net/dccp/ackvec.h
+++ b/net/dccp/ackvec.h
@@ -11,15 +11,14 @@
* published by the Free Software Foundation.
*/
+#include <linux/dccp.h>
#include <linux/compiler.h>
#include <linux/ktime.h>
#include <linux/list.h>
#include <linux/types.h>
-/* Read about the ECN nonce to see why it is 253 */
-#define DCCP_MAX_ACKVEC_OPT_LEN 253
/* We can spread an ack vector across multiple options */
-#define DCCP_MAX_ACKVEC_LEN (DCCP_MAX_ACKVEC_OPT_LEN * 2)
+#define DCCP_MAX_ACKVEC_LEN (DCCP_SINGLE_OPT_MAXLEN * 2)
#define DCCP_ACKVEC_STATE_RECEIVED 0
#define DCCP_ACKVEC_STATE_ECN_MARKED (1 << 6)
diff --git a/net/dccp/feat.h b/net/dccp/feat.h
index 4d17282..093af16 100644
--- a/net/dccp/feat.h
+++ b/net/dccp/feat.h
@@ -22,6 +22,8 @@
/* Wmin=32 and Wmax=2^46-1 from 7.5.2 */
#define DCCPF_SEQ_WMIN 32
#define DCCPF_SEQ_WMAX 0x3FFFFFFFFFFFull
+/* Maximum number of SP values that fit in a single (Confirm) option */
+#define DCCP_FEAT_MAX_SP_VALS (DCCP_SINGLE_OPT_MAXLEN - 2)
enum dccp_feat_type {
FEAT_AT_RX = 1, /* located at RX side of half-connection */
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 8b63394..445884c 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -501,6 +501,36 @@
return rc;
}
+static int dccp_setsockopt_ccid(struct sock *sk, int type,
+ char __user *optval, int optlen)
+{
+ u8 *val;
+ int rc = 0;
+
+ if (optlen < 1 || optlen > DCCP_FEAT_MAX_SP_VALS)
+ return -EINVAL;
+
+ val = kmalloc(optlen, GFP_KERNEL);
+ if (val == NULL)
+ return -ENOMEM;
+
+ if (copy_from_user(val, optval, optlen)) {
+ kfree(val);
+ return -EFAULT;
+ }
+
+ lock_sock(sk);
+ if (type == DCCP_SOCKOPT_TX_CCID || type == DCCP_SOCKOPT_CCID)
+ rc = dccp_feat_register_sp(sk, DCCPF_CCID, 1, val, optlen);
+
+ if (!rc && (type == DCCP_SOCKOPT_RX_CCID || type == DCCP_SOCKOPT_CCID))
+ rc = dccp_feat_register_sp(sk, DCCPF_CCID, 0, val, optlen);
+ release_sock(sk);
+
+ kfree(val);
+ return rc;
+}
+
static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
char __user *optval, int optlen)
{
@@ -515,6 +545,10 @@
case DCCP_SOCKOPT_CHANGE_R:
DCCP_WARN("sockopt(CHANGE_L/R) is deprecated: fix your app\n");
return 0;
+ case DCCP_SOCKOPT_CCID:
+ case DCCP_SOCKOPT_RX_CCID:
+ case DCCP_SOCKOPT_TX_CCID:
+ return dccp_setsockopt_ccid(sk, optname, optval, optlen);
}
if (optlen < (int)sizeof(int))