X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Futcp.c;h=8b3509ef0f5c376ee7b37640cb3c82dba1819df4;hb=0f5ab29d787c7fb444908797d5ea746cb4311be4;hp=f237270f85c7173610c84b447ea314f617fd79dd;hpb=7ece2b2350630584a2268b6b028d545ea69053a3;p=meshlink

diff --git a/src/utcp.c b/src/utcp.c
index f237270f..8b3509ef 100644
--- a/src/utcp.c
+++ b/src/utcp.c
@@ -196,6 +196,16 @@ static bool buffer_wraps(struct buffer *buf) {
 }
 
 static bool buffer_resize(struct buffer *buf, uint32_t newsize) {
+	assert(!buf->external);
+
+	if(!newsize) {
+		free(buf->data);
+		buf->data = NULL;
+		buf->size = 0;
+		buf->offset = 0;
+		return true;
+	}
+
 	char *newdata = realloc(buf->data, newsize);
 
 	if(!newdata) {
@@ -395,8 +405,99 @@ static bool buffer_set_size(struct buffer *buf, uint32_t minsize, uint32_t maxsi
 	return buf->size >= minsize || buffer_resize(buf, minsize);
 }
 
+static void buffer_transfer(struct buffer *buf, char *newdata, size_t newsize) {
+	if(buffer_wraps(buf)) {
+		// Old situation:
+		// [345......012]
+		// New situation:
+		// [012345......]
+		uint32_t tailsize = buf->size - buf->offset;
+		memcpy(newdata, buf->data + buf->offset, tailsize);
+		memcpy(newdata + tailsize, buf->data, buf->used - tailsize);
+	} else {
+		// Old situation:
+		// [....012345..]
+		// New situation:
+		// [012345......]
+		memcpy(newdata, buf->data + buf->offset, buf->used);
+	}
+
+	buf->offset = 0;
+	buf->size = newsize;
+}
+
+static void set_buffer_storage(struct buffer *buf, char *data, size_t size) {
+	if(size > UINT32_MAX) {
+		size = UINT32_MAX;
+	}
+
+	buf->maxsize = size;
+
+	if(data) {
+		if(buf->external) {
+			// Don't allow resizing an external buffer
+			abort();
+		}
+
+		if(size < buf->used) {
+			// Ignore requests for an external buffer if we are already using more than it can store
+			return;
+		}
+
+		// Transition from internal to external buffer
+		buffer_transfer(buf, data, size);
+		free(buf->data);
+		buf->data = data;
+		buf->external = true;
+	} else if(buf->external) {
+		// Transition from external to internal buf
+		size_t minsize = buf->used <= DEFAULT_SNDBUFSIZE ? DEFAULT_SNDBUFSIZE : buf->used;
+
+		if(minsize) {
+			data = malloc(minsize);
+
+			if(!data) {
+				// Cannot handle this
+				abort();
+			}
+
+			buffer_transfer(buf, data, minsize);
+			buf->data = data;
+		} else {
+			buf->data = NULL;
+			buf->size = 0;
+		}
+
+		buf->external = false;
+	} else {
+		// Don't do anything if the buffer wraps
+		if(buffer_wraps(buf)) {
+			return;
+		}
+
+		// Realloc internal storage
+		size_t minsize = max(DEFAULT_SNDBUFSIZE, buf->offset + buf->used);
+
+		if(minsize) {
+			data = realloc(buf->data, minsize);
+
+			if(data) {
+				buf->data = data;
+				buf->size = minsize;
+			}
+		} else {
+			free(buf->data);
+			buf->data = NULL;
+			buf->size = 0;
+		}
+	}
+}
+
 static void buffer_exit(struct buffer *buf) {
-	free(buf->data);
+	if(!buf->external) {
+		free(buf->data);
+	}
+
 	memset(buf, 0, sizeof(*buf));
 }
 
@@ -2011,6 +2112,15 @@ static bool reset_connection(struct utcp_connection *c) {
 	return true;
 }
 
+static void set_reapable(struct utcp_connection *c) {
+	set_buffer_storage(&c->sndbuf, NULL, min(c->sndbuf.maxsize, DEFAULT_MAXSNDBUFSIZE));
+	set_buffer_storage(&c->rcvbuf, NULL, min(c->rcvbuf.maxsize, DEFAULT_MAXRCVBUFSIZE));
+
+	c->recv = NULL;
+	c->poll = NULL;
+	c->reapable = true;
+}
+
 // Closes all the opened connections
 void utcp_abort_all_connections(struct utcp *utcp) {
 	if(!utcp) {
@@ -2028,7 +2138,7 @@ void utcp_abort_all_connections(struct utcp *utcp) {
 		utcp_recv_t old_recv = c->recv;
 		utcp_poll_t old_poll = c->poll;
 
-		reset_connection(c);
+		utcp_abort(c);
 
 		if(old_recv) {
 			errno = 0;
@@ -2049,9 +2159,7 @@ int utcp_close(struct utcp_connection *c) {
 		return -1;
 	}
 
-	c->recv = NULL;
-	c->poll = NULL;
-	c->reapable = true;
+	set_reapable(c);
 	return 0;
 }
 
@@ -2060,7 +2168,7 @@ int utcp_abort(struct utcp_connection *c) {
 		return -1;
 	}
 
-	c->reapable = true;
+	set_reapable(c);
 	return 0;
 }
 
@@ -2315,16 +2423,12 @@ size_t utcp_get_sndbuf_free(struct utcp_connection *c) {
 	}
 }
 
-void utcp_set_sndbuf(struct utcp_connection *c, size_t size) {
+void utcp_set_sndbuf(struct utcp_connection *c, void *data, size_t size) {
 	if(!c) {
 		return;
 	}
 
-	c->sndbuf.maxsize = size;
-
-	if(c->sndbuf.maxsize != size) {
-		c->sndbuf.maxsize = -1;
-	}
+	set_buffer_storage(&c->sndbuf, data, size);
 
 	c->do_poll = is_reliable(c) && buffer_free(&c->sndbuf);
 }
@@ -2341,16 +2445,12 @@ size_t utcp_get_rcvbuf_free(struct utcp_connection *c) {
 	}
 }
 
-void utcp_set_rcvbuf(struct utcp_connection *c, size_t size) {
+void utcp_set_rcvbuf(struct utcp_connection *c, void *data, size_t size) {
 	if(!c) {
 		return;
 	}
 
-	c->rcvbuf.maxsize = size;
-
-	if(c->rcvbuf.maxsize != size) {
-		c->rcvbuf.maxsize = -1;
-	}
+	set_buffer_storage(&c->rcvbuf, data, size);
 }
 
 size_t utcp_get_sendq(struct utcp_connection *c) {