ipa: Change ipa_msg_recv() to support partial receive
Currently ipa_msg_recv() fails, when messages are received partially.
This patch provides a new function ipa_msg_recv_buffered() that uses
an additional ** to a message buffer to store partial data. When
this happens, -EAGAIN is returned. If NULL is used, the function
behaves similar to ipa_msg_recv() and fails on partial read.
In addition in case of errors the return value is now always -EXXX
and the contents of errno is undefined.
Note that this feature needs support by the calling code insofar that
*tmp_msg must be set to NULL initially and it must be freed and
set to NULL manually when the socket is closed.
Note also that ipa_msg_recv() is then a wrapper around
ipa_msg_recv_buffered() which mimics the old error behaviour by
setting errno explicitely to -rc and returning -1 when an error has
happened.
Ticket: OW#728
Sponsored-by: On-Waves ehf
diff --git a/tests/ipa_recv/ipa_recv_test.c b/tests/ipa_recv/ipa_recv_test.c
index af87c27..0f56926 100644
--- a/tests/ipa_recv/ipa_recv_test.c
+++ b/tests/ipa_recv/ipa_recv_test.c
@@ -65,7 +65,7 @@
strcpy((char *)l2, text);
}
-static int receive_messages(int fd)
+static int receive_messages(int fd, struct msgb **pending_msg)
{
struct msgb *msg;
char dummy;
@@ -76,13 +76,22 @@
break;
}
msg = NULL;
- rc = ipa_msg_recv(fd, &msg);
- if (rc == -1)
- rc = -errno;
+ rc = ipa_msg_recv_buffered(fd, &msg, pending_msg);
+
fprintf(stderr,
- "ipa_msg_recv: %d, msg %s NULL\n",
- rc, msg ? "!=" : "==");
- if (rc == -EAGAIN)
+ "ipa_msg_recv_buffered: %d, msg %s NULL, "
+ "pending_msg %s NULL\n",
+ rc, msg ? "!=" : "==",
+ !pending_msg ? "??" : *pending_msg ? "!=" : "==");
+ if (pending_msg && !!msg == !!*pending_msg)
+ printf( "got msg %s NULL, pending_msg %s NULL, "
+ "returned: %s\n",
+ msg ? "!=" : "==",
+ *pending_msg ? "!=" : "==",
+ rc == 0 ? "EOF" :
+ rc > 0 ? "OK" :
+ strerror(-rc));
+ else if (!pending_msg && rc == -EAGAIN)
printf( "got msg %s NULL, "
"returned: %s\n",
msg ? "!=" : "==",
@@ -94,7 +103,8 @@
if (rc == -EAGAIN)
break;
if (rc < 0) {
- printf("ipa_msg_recv failed with: %s\n", strerror(-rc));
+ printf("ipa_msg_recv_buffered failed with: %s\n",
+ strerror(-rc));
return rc;
}
printf("got IPA message, size=%d, proto=%d, text=\"%s\"\n",
@@ -121,13 +131,15 @@
return count;
};
-static void test_complete_recv(void)
+static void test_complete_recv(int do_not_assemble)
{
int sv[2];
struct msgb *msg_out = msgb_alloc(4096, "msg_out");
+ struct msgb *pending_msg = NULL;
int rc, i;
- printf("Testing IPA recv with complete messages.\n");
+ printf("Testing IPA recv with complete messages%s.\n",
+ do_not_assemble ? "" : " with assembling enabled");
if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == -1)
err(1, "socketpair");
@@ -145,7 +157,11 @@
}
for (i=0; i < ARRAY_SIZE(ipa_test_messages); i++) {
- rc = receive_messages(sv[0]);
+ rc = receive_messages(sv[0],
+ do_not_assemble ? NULL : &pending_msg);
+ if (pending_msg)
+ printf("Unexpected partial message: size=%d\n",
+ pending_msg->len);
if (rc == 0)
break;
@@ -160,16 +176,19 @@
close(sv[0]);
msgb_free(msg_out);
+ msgb_free(pending_msg);
}
-static void test_partial_recv(void)
+static void test_partial_recv(int do_not_assemble)
{
int sv[2];
struct msgb *msg_out = msgb_alloc(4096, "msg_out");
+ struct msgb *pending_msg = NULL;
int rc, i;
- printf("Testing IPA recv with partitioned messages.\n");
+ printf("Testing IPA recv with partitioned messages%s.\n",
+ do_not_assemble ? "" : " with assembling enabled");
if (socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == -1)
err(1, "socketpair");
@@ -190,7 +209,8 @@
if (msg_out->len == 0)
shutdown(sv[1], SHUT_WR);
- rc = receive_messages(sv[0]);
+ rc = receive_messages(sv[0],
+ do_not_assemble ? NULL : &pending_msg);
if (rc == 0)
break;
@@ -205,6 +225,7 @@
close(sv[0]);
msgb_free(msg_out);
+ msgb_free(pending_msg);
}
static struct log_info info = {};
@@ -218,8 +239,10 @@
printf("Testing the IPA layer.\n");
/* run the tests */
- test_complete_recv();
- test_partial_recv();
+ test_complete_recv(1);
+ test_partial_recv(1);
+ test_complete_recv(0);
+ test_partial_recv(0);
printf("No crashes.\n");
return 0;