Fragment reassembly. Add reassembly of fragmented RPC PDUs

diff --git a/include/libnfs-private.h b/include/libnfs-private.h
index 85cc8f979b0a9a0597af5735733437de12f66715..a8f5d26247ea7e3d494e59a0283b4733de4e7efa 100644 (file)
--- 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 45aa78da9f295acb92c5da2d333a53744801b170..93c3745db446ae57483466401e8ba4ba4b32c647 100644 (file)
--- 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 d7426ced53c82a50748b243d130b09ad2c1dab06..8cfae610b83c6819035537ce89518d5c65ec7c2a 100644 (file)
--- 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;
 }