(Attachment hopefully not stripped now)
On Tuesday 07 April 2009 23:56:18 Ivan Skytte Jørgensen wrote:
> On Monday 30 March 2009 19:46:11 Vlad Yasevich wrote:
> > Ivan Skytte Jørgensen wrote:
>
> ...
>
> > >>> So there is a need for the system call to return both a value and an
> > >>> error code at the same time.
> > >
> > > Having taken a closer look at the kernel side I think I can whip up a
> > > complete patch for this.
> >
> > OK. Looks like it will need yet a third socket option that takes the
> > sctp_getaddrs structure.
> >
> > Looking forward to this code.
>
> Attached: patch for lksctp-1.0.10 and kernel 2.6.29.1
>
> Tested on kernel 2.6.27.19 on both 32bit and 64bit.
>
> Signed-off-by: Ivan Skytte Jørgensen <isj-sctp@xxxxx>
>
> * Support non-blocking sctp_connectx() calls returning the future
> association-id.
>
>
> Some notes on the user library part:
>
> 1: I decided to keep the previous "new" sctp_connectx() implementation,
> because a: it costs nothing, and b: some very recent programs may rely on
> the broken behaviour.
>
> 2: The new-new sctp_connectx() tries the new method first. If it fails due
> to ENOPROTOOPT (old kernel) then it falls back to the old method first, but
> only if it is safe to do so (blocking socket, or assoc_id not returned)
>
> 3: (note of users of this feature): If a non-blocking connect fails quickly
> then a new call to sctp_connectx() may return an identical association id
> becaue the ID has been freed up already.
>
> Regards,
> Ivan
diff -U3 -p -r lksctp-tools-1.0.10/src/include/netinet/sctp.h lksctp-tools-1.0.11/src/include/netinet/sctp.h
--- lksctp-tools-1.0.10/src/include/netinet/sctp.h 2008-10-09 22:17:26.000000000 +0200
+++ lksctp-tools-1.0.11/src/include/netinet/sctp.h 2009-04-05 17:11:16.000000000 +0200
@@ -146,6 +146,8 @@ enum sctp_optname {
#define SCTP_GET_LOCAL_ADDRS SCTP_GET_LOCAL_ADDRS
SCTP_SOCKOPT_CONNECTX, /* CONNECTX requests. NEW implementation */
#define SCTP_SOCKOPT_CONNECTX SCTP_SOCKOPT_CONNECTX
+ SCTP_SOCKOPT_CONNECTX3, /* CONNECTX requests. NEW, NEW implementation */
+#define SCTP_SOCKOPT_CONNECTX3 SCTP_SOCKOPT_CONNECTX3
};
/*
diff -U3 -p -r lksctp-tools-1.0.10/src/lib/Versions.map lksctp-tools-1.0.11/src/lib/Versions.map
--- lksctp-tools-1.0.10/src/lib/Versions.map 2008-10-09 22:17:26.000000000 +0200
+++ lksctp-tools-1.0.11/src/lib/Versions.map 2009-04-05 16:57:47.000000000 +0200
@@ -20,3 +20,7 @@ VERS_1 {
VERS_2 {
global: sctp_connectx;
} VERS_1;
+
+VERS_3 {
+ global: sctp_connectx;
+} VERS_2;
diff -U3 -p -r lksctp-tools-1.0.10/src/lib/connectx.c lksctp-tools-1.0.11/src/lib/connectx.c
--- lksctp-tools-1.0.10/src/lib/connectx.c 2008-10-09 22:17:26.000000000 +0200
+++ lksctp-tools-1.0.11/src/lib/connectx.c 2009-04-07 20:31:37.000000000 +0200
@@ -23,7 +23,9 @@
#include <netinet/in.h>
#include <netinet/sctp.h> /* SCTP_SOCKOPT_CONNECTX_* */
#include <errno.h>
-#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
/* Support the sctp_connectx() interface.
*
@@ -35,14 +37,14 @@
static int __connectx_addrsize(const struct sockaddr *addrs,
const int addrcnt)
{
- void *addrbuf;
- struct sockaddr *sa_addr;
+ const void *addrbuf;
+ const struct sockaddr *sa_addr;
int addrs_size = 0;
int i;
addrbuf = addrs;
for (i = 0; i < addrcnt; i++) {
- sa_addr = (struct sockaddr *)addrbuf;
+ sa_addr = (const struct sockaddr *)addrbuf;
switch (sa_addr->sa_family) {
case AF_INET:
addrs_size += sizeof(struct sockaddr_in);
@@ -106,6 +108,82 @@ int sctp_connectx_new(int fd, struct soc
return status;
}
+int sctp_connectx3(int fd, struct sockaddr *addrs, int addrcnt,
+ sctp_assoc_t *id)
+{
+ socklen_t addrs_size = __connectx_addrsize(addrs, addrcnt);
+ int status;
+ char *new_api_buffer;
+
+ if (addrs_size < 0)
+ return -1;
+
+ /* First try the new socket api */
+ /* Because the id is returned in the option buffer we have prepend
+ * 32bit to it for the returned association id */
+ new_api_buffer = (char*)malloc(sizeof(uint32_t)+addrs_size);
+ if(new_api_buffer) {
+ socklen_t option_len = addrs_size+sizeof(uint32_t);
+ memset(new_api_buffer,0,sizeof(uint32_t));
+ memcpy(new_api_buffer+sizeof(uint32_t),addrs,addrs_size);
+ status = getsockopt(fd, SOL_SCTP, SCTP_SOCKOPT_CONNECTX3,
+ new_api_buffer, &option_len);
+ if(status==0 ||
+ errno==EINPROGRESS) {
+ /* Succeeded immediately, or initiated on non-blocking
+ * socket */
+ if(id)
+ *id = *(uint32_t*)new_api_buffer;
+ free(new_api_buffer);
+ return status;
+ }
+ free(new_api_buffer);
+ if(errno != ENOPROTOOPT) {
+ /* No point in trying the fallbacks*/
+ return status;
+ }
+ }
+
+ /* Second, try the "new" api, which doesn't work for non-blocking sockets */
+ if(id) {
+ /* Program wants the association-id returned. We can only do
+ * that if the socket is blocking */
+ status = fcntl(fd, F_GETFL);
+ if(status < 0)
+ return status;
+ if(status & O_NONBLOCK) {
+ /* Socket is non-blocking. Fail */
+ errno = ENOPROTOOPT;
+ return -1;
+ }
+ }
+ /* The id is not wanted, or the socket is blocking, so it is ok to
+ * call use the fallback */
+ status = setsockopt(fd, SOL_SCTP, SCTP_SOCKOPT_CONNECTX, addrs,
+ addrs_size);
+ if(status > 0) {
+ if(id)
+ *id = status;
+ return 0;
+ }
+ if(status < 0 && errno!=ENOPROTOOPT) {
+ /* Some other kind of error. No point in continuing */
+ return status;
+ }
+
+ /*Third, try the old, old API */
+ if(id) {
+ /* If the application wants the id then we cannot do it with
+ * the old API */
+ errno = ENOPROTOOPT;
+ return -1;
+ }
+
+ return setsockopt(fd, SOL_SCTP, SCTP_SOCKOPT_CONNECTX_OLD,
+ addrs, addrs_size);
+}
+
__asm__(".symver __sctp_connectx, sctp_connectx@");
__asm__(".symver sctp_connectx_orig, sctp_connectx@VERS_1");
-__asm__(".symver sctp_connectx_new, sctp_connectx@@VERS_2");
+__asm__(".symver sctp_connectx_new, sctp_connectx@VERS_2");
+__asm__(".symver sctp_connectx3, sctp_connectx@@VERS_3");
diff -U3 -r -p /usr/src/linux/include/net/sctp/user.h linux-2.6.27.19-3.2/include/net/sctp/user.h
--- /usr/src/linux/include/net/sctp/user.h 2008-10-10 00:13:53.000000000 +0200
+++ linux-2.6.27.19-3.2/include/net/sctp/user.h 2009-04-05 17:41:15.000000000 +0200
@@ -145,6 +145,8 @@ enum sctp_optname {
#define SCTP_GET_LOCAL_ADDRS SCTP_GET_LOCAL_ADDRS
SCTP_SOCKOPT_CONNECTX, /* CONNECTX requests. */
#define SCTP_SOCKOPT_CONNECTX SCTP_SOCKOPT_CONNECTX
+ SCTP_SOCKOPT_CONNECTX3, /* CONNECTX requests. (new implementation) */
+#define SCTP_SOCKOPT_CONNECTX3 SCTP_SOCKOPT_CONNECTX3
};
/*
diff -U3 -r -p /usr/src/linux/net/sctp/associola.c linux-2.6.27.19-3.2/net/sctp/associola.c
--- /usr/src/linux/net/sctp/associola.c 2008-10-10 00:13:53.000000000 +0200
+++ linux-2.6.27.19-3.2/net/sctp/associola.c 2009-04-07 20:30:47.000000000 +0200
@@ -1481,6 +1481,10 @@ int sctp_assoc_set_id(struct sctp_associ
{
int assoc_id;
int error = 0;
+
+ /* If the id is already assigned, keep it. */
+ if (asoc->assoc_id)
+ return error;
retry:
if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
return -ENOMEM;
diff -U3 -r -p /usr/src/linux/net/sctp/socket.c linux-2.6.27.19-3.2/net/sctp/socket.c
--- /usr/src/linux/net/sctp/socket.c 2008-10-10 00:13:53.000000000 +0200
+++ linux-2.6.27.19-3.2/net/sctp/socket.c 2009-04-07 20:30:38.000000000 +0200
@@ -1100,6 +1100,15 @@ static int __sctp_connect(struct sock* s
goto out_free;
}
+ /* In case the user of sctp_connectx() wants an association
+ * id back, assign one now.
+ */
+ if (assoc_id) {
+ err = sctp_assoc_set_id(asoc, GFP_KERNEL);
+ if (err < 0)
+ goto out_free;
+ }
+
err = sctp_primitive_ASSOCIATE(asoc, NULL);
if (err < 0) {
goto out_free;
@@ -1120,7 +1129,7 @@ static int __sctp_connect(struct sock* s
timeo = sock_sndtimeo(sk, f_flags & O_NONBLOCK);
err = sctp_wait_for_connect(asoc, &timeo);
- if (!err && assoc_id)
+ if ((err == 0 || err == -EINPROGRESS) && assoc_id)
*assoc_id = asoc->assoc_id;
/* Don't free association on exit. */
@@ -1264,6 +1273,32 @@ SCTP_STATIC int sctp_setsockopt_connectx
return assoc_id;
}
+/*
+ * New (hopefully final) interface for the API. The option buffer is used
+ * both for the returned association id and the addresses.
+ */
+SCTP_STATIC int sctp_getsockopt_connectx3(struct sock* sk, int len,
+ char __user *optval,
+ int __user *optlen)
+{
+ sctp_assoc_t assoc_id = 0;
+ int err = 0;
+
+ if(len < 4)
+ return -EINVAL;
+
+ err = __sctp_setsockopt_connectx(sk, (struct sockaddr __user *)(optval+4), len-4, &assoc_id);
+
+ if (err >= 0 || err==-EINPROGRESS) {
+ if (put_user(assoc_id, optval))
+ return -EFAULT;
+ if (put_user(4, optlen))
+ return -EFAULT;
+ }
+
+ return err;
+}
+
/* API 3.1.4 close() - UDP Style Syntax
* Applications use close() to perform graceful shutdown (as described in
* Section 10.1 of [SCTP]) on ALL the associations currently represented
@@ -5447,6 +5482,9 @@ SCTP_STATIC int sctp_getsockopt(struct s
retval = sctp_getsockopt_local_addrs(sk, len, optval,
optlen);
break;
+ case SCTP_SOCKOPT_CONNECTX3:
+ retval = sctp_getsockopt_connectx3(sk, len, optval, optlen);
+ break;
case SCTP_DEFAULT_SEND_PARAM:
retval = sctp_getsockopt_default_send_param(sk, len,
optval, optlen);
