posix: implement MSG_PEEK handling in unix socket recv

JIRA: RTOS-877
phoenix-rtos · Sep 3, 2024 · 56bb686 · 56bb686
1 parent 46fa5dd
commit 56bb686
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Showing 3 changed files with 36 additions and 11 deletions.
diff --git a/lib/cbuffer.c b/lib/cbuffer.c
@@ -56,6 +56,19 @@ int _cbuffer_write(cbuffer_t *buf, const void *data, size_t sz)
 
 
 int _cbuffer_read(cbuffer_t *buf, void *data, size_t sz)
+{
+	int bytes = _cbuffer_peek(buf, data, sz);
+
+	if (bytes > 0) {
+		buf->r = (buf->r + bytes) & (buf->sz - 1);
+		buf->full = 0;
+	}
+
+	return bytes;
+}
+
+
+int _cbuffer_peek(const cbuffer_t *buf, void *data, size_t sz)
 {
 	int bytes = 0;
 
@@ -76,8 +89,5 @@ int _cbuffer_read(cbuffer_t *buf, void *data, size_t sz)
 		}
 	}
 
-	buf->r = (buf->r + bytes) & (buf->sz - 1);
-	buf->full = 0;
-
 	return bytes;
 }
diff --git a/lib/cbuffer.h b/lib/cbuffer.h
@@ -56,4 +56,6 @@ extern int _cbuffer_read(cbuffer_t *buf, void *data, size_t sz);
 extern int _cbuffer_write(cbuffer_t *buf, const void *data, size_t sz);
 
 
-#endif
+extern int _cbuffer_peek(const cbuffer_t *buf, void *data, size_t sz);
+
+#endif
diff --git a/posix/unix.c b/posix/unix.c
@@ -679,6 +679,9 @@ static ssize_t recv(unsigned socket, void *buf, size_t len, int flags, struct so
 	size_t rlen = 0;
 	int err;
 	spinlock_ctx_t sc;
+	int peek;
+
+	peek = (flags & MSG_PEEK) != 0;
 
 	if ((s = unixsock_get(socket)) == NULL)
 		return -ENOTSOCK;
@@ -694,24 +697,34 @@ static ssize_t recv(unsigned socket, void *buf, size_t len, int flags, struct so
 		for (;;) {
 			proc_lockSet(&s->lock);
 			if (s->type == SOCK_STREAM) {
-				err = _cbuffer_read(&s->buffer, buf, len);
+				if (peek) {
+					err = _cbuffer_peek(&s->buffer, buf, len);
+				}
+				else {
+					err = _cbuffer_read(&s->buffer, buf, len);
+				}
 			}
 			else if (_cbuffer_avail(&s->buffer) > 0) { /* SOCK_DGRAM or SOCK_SEQPACKET */
+				/* TODO: handle MSG_PEEK */
 				_cbuffer_read(&s->buffer, &rlen, sizeof(rlen));
 				_cbuffer_read(&s->buffer, buf, err = min(len, rlen));
 
 				if (len < rlen)
 					_cbuffer_discard(&s->buffer, rlen - len);
 			}
-			if (err > 0 && control && controllen && *controllen > 0)
-				fdpass_unpack(&s->fdpacks, control, controllen);
+			/* TODO: peek control data */
+			if (!peek) {
+				if (err > 0 && control && controllen && *controllen > 0)
+					fdpass_unpack(&s->fdpacks, control, controllen);
+			}
 			proc_lockClear(&s->lock);
 
 			if (err > 0) {
-				hal_spinlockSet(&s->spinlock, &sc);
-				proc_threadWakeup(&s->writeq);
-				hal_spinlockClear(&s->spinlock, &sc);
-
+				if (!peek) {
+					hal_spinlockSet(&s->spinlock, &sc);
+					proc_threadWakeup(&s->writeq);
+					hal_spinlockClear(&s->spinlock, &sc);
+				}
 				break;
 			}
 			else if (s->type != SOCK_DGRAM && (s->state & US_PEER_CLOSED)) {