From: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Date: Tue, 4 Oct 2011 01:31:56 +0000 (+1100)
Subject: Fragment reassembly. Add reassembly of fragmented RPC PDUs
X-Git-Tag: upstream/1.9.6^2~292
X-Git-Url: https://git.piment-noir.org/?a=commitdiff_plain;h=d678b73e4d21fb34f302a65b8bcc340c2accdb96;p=deb_libnfs.git

Fragment reassembly. Add reassembly of fragmented RPC PDUs
---

diff --git a/include/libnfs-private.h b/include/libnfs-private.h
index 85cc8f9..a8f5d26 100644
--- a/include/libnfs-private.h
+++ b/include/libnfs-private.h
@@ -17,6 +17,12 @@
 #include <rpc/xdr.h>
 #include <rpc/auth.h>
 
+struct rpc_fragment {
+	struct rpc_fragment *next;
+	size_t size;
+	char *data;
+};
+
 struct rpc_context {
 	int fd;
 	int is_connected;
@@ -49,6 +55,9 @@ struct rpc_context {
        /* track the address we connect to so we can auto-reconnect on session failure */
        struct sockaddr_storage s;
        int auto_reconnect;
+
+	/* fragment reassembly */
+	struct rpc_fragment *fragments;
 };
 
 struct rpc_pdu {
@@ -92,3 +101,6 @@ struct sockaddr *rpc_get_recv_sockaddr(struct rpc_context *rpc);
 void rpc_set_autoreconnect(struct rpc_context *rpc);
 void rpc_unset_autoreconnect(struct rpc_context *rpc);
 
+int rpc_add_fragment(struct rpc_context *rpc, char *data, size_t size);
+void rpc_free_all_fragments(struct rpc_context *rpc);
+
diff --git a/lib/init.c b/lib/init.c
index 45aa78d..93c3745 100644
--- a/lib/init.c
+++ b/lib/init.c
@@ -120,6 +120,44 @@ void rpc_error_all_pdus(struct rpc_context *rpc, char *error)
 	}
 }
 
+static void rpc_free_fragment(struct rpc_fragment *fragment)
+{
+	if (fragment->data != NULL) {
+		free(fragment->data);
+	}
+	free(fragment);
+}
+
+void rpc_free_all_fragments(struct rpc_context *rpc)
+{
+	while (rpc->fragments != NULL) {
+	      struct rpc_fragment *fragment = rpc->fragments;
+
+	      SLIST_REMOVE(&rpc->fragments, fragment);
+	      rpc_free_fragment(fragment);
+	}
+}
+
+int rpc_add_fragment(struct rpc_context *rpc, char *data, size_t size)
+{
+	struct rpc_fragment *fragment;
+
+	fragment = malloc(sizeof(struct rpc_fragment));
+	if (fragment == NULL) {
+		return -1;
+	}
+
+	fragment->size = size;
+	fragment->data = malloc(fragment->size);
+	if(fragment->data == NULL) {
+		free(fragment);
+		return -1;
+	}
+
+	memcpy(fragment->data, data, fragment->size);
+	SLIST_ADD_END(&rpc->fragments, fragment);
+	return 0;
+}
 
 void rpc_destroy_context(struct rpc_context *rpc)
 {
@@ -136,6 +174,8 @@ void rpc_destroy_context(struct rpc_context *rpc)
 		rpc_free_pdu(rpc, pdu);
 	}
 
+	rpc_free_all_fragments(rpc);
+
 	auth_destroy(rpc->auth);
 	rpc->auth =NULL;
 
diff --git a/lib/pdu.c b/lib/pdu.c
index d7426ce..8cfae61 100644
--- a/lib/pdu.c
+++ b/lib/pdu.c
@@ -141,11 +141,6 @@ int rpc_get_pdu_size(char *buf)
 
 	size = ntohl(*(uint32_t *)buf);
 
-	if ((size & 0x80000000) == 0) {
-		/* cant handle oncrpc fragments */
-		return -1;
-	}
-
 	return (size & 0x7fffffff) + 4;
 }
 
@@ -214,8 +209,9 @@ int rpc_process_pdu(struct rpc_context *rpc, char *buf, int size)
 {
 	struct rpc_pdu *pdu;
 	XDR xdr;
-	int pos, recordmarker;
+	int pos, recordmarker = 0;
 	unsigned int xid;
+	char *reasbuf = NULL;
 
 	memset(&xdr, 0, sizeof(XDR));
 
@@ -226,11 +222,50 @@ int rpc_process_pdu(struct rpc_context *rpc, char *buf, int size)
 			xdr_destroy(&xdr);
 			return -1;
 		}
+		if (!(recordmarker&0x80000000)) {
+			xdr_destroy(&xdr);
+			if (rpc_add_fragment(rpc, buf+4, size-4) != 0) {
+				rpc_set_error(rpc, "Failed to queue fragment for reassembly.");
+				return -1;
+			}
+			return 0;
+		}
 	}
+
+	/* reassembly */
+	if (recordmarker != 0 && rpc->fragments != NULL) {
+		struct rpc_fragment *fragment;
+		size_t total = size - 4;
+		char *ptr;
+
+		xdr_destroy(&xdr);
+		for (fragment = rpc->fragments; fragment; fragment = fragment->next) {
+			total += fragment->size;
+		}
+
+		reasbuf = malloc(total);
+		if (reasbuf == NULL) {
+			rpc_set_error(rpc, "Failed to reassemble PDU");
+			rpc_free_all_fragments(rpc);
+			return -1;
+		}
+		ptr = reasbuf;
+		for (fragment = rpc->fragments; fragment; fragment = fragment->next) {
+			memcpy(ptr, fragment->data, fragment->size);
+			ptr += fragment->size;
+		}
+		memcpy(ptr, buf + 4, size - 4);
+		xdrmem_create(&xdr, reasbuf, total, XDR_DECODE);
+		rpc_free_all_fragments(rpc);
+	}
+
 	pos = xdr_getpos(&xdr);
 	if (xdr_int(&xdr, (int *)&xid) == 0) {
 		rpc_set_error(rpc, "xdr_int reading xid failed");
 		xdr_destroy(&xdr);
+		if (reasbuf != NULL) {
+			free(reasbuf);
+		}
 		return -1;
 	}
 	xdr_setpos(&xdr, pos);
@@ -249,10 +284,16 @@ int rpc_process_pdu(struct rpc_context *rpc, char *buf, int size)
 		if (rpc->is_udp == 0 || rpc->is_broadcast == 0) {
 			rpc_free_pdu(rpc, pdu);
 		}
+		if (reasbuf != NULL) {
+			free(reasbuf);
+		}
 		return 0;
 	}
 	rpc_set_error(rpc, "No matching pdu found for xid:%d", xid);
 	xdr_destroy(&xdr);
+	if (reasbuf != NULL) {
+		free(reasbuf);
+	}
 	return -1;
 }