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authorWei Yongjun <yjwei@cn.fujitsu.com>2008-12-25 16:54:58 -0800
committerDavid S. Miller <davem@davemloft.net>2008-12-25 16:54:58 -0800
commite89c2095815d82eaa9fb85eff42f8b65b67a59cf (patch)
treea6ee89692051c0fa1328b8b79c3b9d7b44dbeab5 /net
parent161c8d2f50109b44b664eaf23831ea1587979a61 (diff)
downloadlinux-2.6.34-ux500-e89c2095815d82eaa9fb85eff42f8b65b67a59cf.tar.gz
sctp: Bring SCTP_MAXSEG socket option into ietf API extension compliance
Brings maxseg socket option set/get into line with the latest ietf socket extensions API draft, while maintaining backwards compatibility. Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/sctp/socket.c130
1 files changed, 107 insertions, 23 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index a2de585888d..0738843876a 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -2778,32 +2778,77 @@ static int sctp_setsockopt_mappedv4(struct sock *sk, char __user *optval, int op
}
/*
- * 7.1.17 Set the maximum fragrmentation size (SCTP_MAXSEG)
- *
- * This socket option specifies the maximum size to put in any outgoing
- * SCTP chunk. If a message is larger than this size it will be
+ * 8.1.16. Get or Set the Maximum Fragmentation Size (SCTP_MAXSEG)
+ * This option will get or set the maximum size to put in any outgoing
+ * SCTP DATA chunk. If a message is larger than this size it will be
* fragmented by SCTP into the specified size. Note that the underlying
* SCTP implementation may fragment into smaller sized chunks when the
* PMTU of the underlying association is smaller than the value set by
- * the user.
+ * the user. The default value for this option is '0' which indicates
+ * the user is NOT limiting fragmentation and only the PMTU will effect
+ * SCTP's choice of DATA chunk size. Note also that values set larger
+ * than the maximum size of an IP datagram will effectively let SCTP
+ * control fragmentation (i.e. the same as setting this option to 0).
+ *
+ * The following structure is used to access and modify this parameter:
+ *
+ * struct sctp_assoc_value {
+ * sctp_assoc_t assoc_id;
+ * uint32_t assoc_value;
+ * };
+ *
+ * assoc_id: This parameter is ignored for one-to-one style sockets.
+ * For one-to-many style sockets this parameter indicates which
+ * association the user is performing an action upon. Note that if
+ * this field's value is zero then the endpoints default value is
+ * changed (effecting future associations only).
+ * assoc_value: This parameter specifies the maximum size in bytes.
*/
static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, int optlen)
{
+ struct sctp_assoc_value params;
struct sctp_association *asoc;
struct sctp_sock *sp = sctp_sk(sk);
int val;
- if (optlen < sizeof(int))
+ if (optlen == sizeof(int)) {
+ printk(KERN_WARNING
+ "SCTP: Use of int in maxseg socket option deprecated\n");
+ printk(KERN_WARNING
+ "SCTP: Use struct sctp_assoc_value instead\n");
+ if (copy_from_user(&val, optval, optlen))
+ return -EFAULT;
+ params.assoc_id = 0;
+ } else if (optlen == sizeof(struct sctp_assoc_value)) {
+ if (copy_from_user(&params, optval, optlen))
+ return -EFAULT;
+ val = params.assoc_value;
+ } else
return -EINVAL;
- if (get_user(val, (int __user *)optval))
- return -EFAULT;
+
if ((val != 0) && ((val < 8) || (val > SCTP_MAX_CHUNK_LEN)))
return -EINVAL;
- sp->user_frag = val;
- /* Update the frag_point of the existing associations. */
- list_for_each_entry(asoc, &(sp->ep->asocs), asocs) {
- asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
+ asoc = sctp_id2assoc(sk, params.assoc_id);
+ if (!asoc && params.assoc_id && sctp_style(sk, UDP))
+ return -EINVAL;
+
+ if (asoc) {
+ if (val == 0) {
+ val = asoc->pathmtu;
+ val -= sp->pf->af->net_header_len;
+ val -= sizeof(struct sctphdr) +
+ sizeof(struct sctp_data_chunk);
+ }
+
+ asoc->frag_point = val;
+ } else {
+ sp->user_frag = val;
+
+ /* Update the frag_point of the existing associations. */
+ list_for_each_entry(asoc, &(sp->ep->asocs), asocs) {
+ asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
+ }
}
return 0;
@@ -5100,30 +5145,69 @@ static int sctp_getsockopt_context(struct sock *sk, int len,
}
/*
- * 7.1.17 Set the maximum fragrmentation size (SCTP_MAXSEG)
- *
- * This socket option specifies the maximum size to put in any outgoing
- * SCTP chunk. If a message is larger than this size it will be
+ * 8.1.16. Get or Set the Maximum Fragmentation Size (SCTP_MAXSEG)
+ * This option will get or set the maximum size to put in any outgoing
+ * SCTP DATA chunk. If a message is larger than this size it will be
* fragmented by SCTP into the specified size. Note that the underlying
* SCTP implementation may fragment into smaller sized chunks when the
* PMTU of the underlying association is smaller than the value set by
- * the user.
+ * the user. The default value for this option is '0' which indicates
+ * the user is NOT limiting fragmentation and only the PMTU will effect
+ * SCTP's choice of DATA chunk size. Note also that values set larger
+ * than the maximum size of an IP datagram will effectively let SCTP
+ * control fragmentation (i.e. the same as setting this option to 0).
+ *
+ * The following structure is used to access and modify this parameter:
+ *
+ * struct sctp_assoc_value {
+ * sctp_assoc_t assoc_id;
+ * uint32_t assoc_value;
+ * };
+ *
+ * assoc_id: This parameter is ignored for one-to-one style sockets.
+ * For one-to-many style sockets this parameter indicates which
+ * association the user is performing an action upon. Note that if
+ * this field's value is zero then the endpoints default value is
+ * changed (effecting future associations only).
+ * assoc_value: This parameter specifies the maximum size in bytes.
*/
static int sctp_getsockopt_maxseg(struct sock *sk, int len,
char __user *optval, int __user *optlen)
{
- int val;
+ struct sctp_assoc_value params;
+ struct sctp_association *asoc;
- if (len < sizeof(int))
+ if (len == sizeof(int)) {
+ printk(KERN_WARNING
+ "SCTP: Use of int in maxseg socket option deprecated\n");
+ printk(KERN_WARNING
+ "SCTP: Use struct sctp_assoc_value instead\n");
+ params.assoc_id = 0;
+ } else if (len >= sizeof(struct sctp_assoc_value)) {
+ len = sizeof(struct sctp_assoc_value);
+ if (copy_from_user(&params, optval, sizeof(params)))
+ return -EFAULT;
+ } else
return -EINVAL;
- len = sizeof(int);
+ asoc = sctp_id2assoc(sk, params.assoc_id);
+ if (!asoc && params.assoc_id && sctp_style(sk, UDP))
+ return -EINVAL;
+
+ if (asoc)
+ params.assoc_value = asoc->frag_point;
+ else
+ params.assoc_value = sctp_sk(sk)->user_frag;
- val = sctp_sk(sk)->user_frag;
if (put_user(len, optlen))
return -EFAULT;
- if (copy_to_user(optval, &val, len))
- return -EFAULT;
+ if (len == sizeof(int)) {
+ if (copy_to_user(optval, &params.assoc_value, len))
+ return -EFAULT;
+ } else {
+ if (copy_to_user(optval, &params, len))
+ return -EFAULT;
+ }
return 0;
}