lib: Retire packet buffering feature.

OVS implementation of buffering packets that are sent to the
controller is not compliant with the OpenFlow specifications after
OpenFlow 1.0, which is possibly true since OpenFlow 1.0 is not really
specifying the packet buffering behavior.

OVS implementation executes the buffered packet against the actions of
the modified or added rule, whereas OpenFlow (since 1.1) specifies
that the packet should be matched against the flow table 0 and
processed accordingly.

Rather than fix this behavior, and potentially break OVS users, the
packet buffering feature is removed altogether.  After all, such
packet buffering is an optional OpenFlow feature, and as such any
possible users should continue to work without this feature.

This patch also makes OVS check the received 'buffer_id' values more
rigorously, and fixes some internal users accordingly.

Found by inspection.

Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Acked-by: Ben Pfaff <blp@ovn.org>

1 files changed, 0 insertions, 220 deletions

diff --git a/lib/pktbuf.c b/lib/pktbuf.c
deleted file mode 100644
index e2c61fd4d..000000000
--- a/lib/pktbuf.c
+++ /dev/null
@@ -1,220 +0,0 @@
-/*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2016 Nicira, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include <config.h>
-#include "pktbuf.h"
-#include <inttypes.h>
-#include <stdlib.h>
-#include "coverage.h"
-#include "openvswitch/ofp-util.h"
-#include "dp-packet.h"
-#include "timeval.h"
-#include "util.h"
-#include "openvswitch/vconn.h"
-#include "openvswitch/vlog.h"
-
-VLOG_DEFINE_THIS_MODULE(pktbuf);
-
-COVERAGE_DEFINE(pktbuf_buffer_unknown);
-COVERAGE_DEFINE(pktbuf_retrieved);
-COVERAGE_DEFINE(pktbuf_reuse_error);
-
-/* Buffers are identified by a 32-bit opaque ID.  We divide the ID
- * into a buffer number (low bits) and a cookie (high bits).  The buffer number
- * is an index into an array of buffers.  The cookie distinguishes between
- * different packets that have occupied a single buffer.  Thus, the more
- * buffers we have, the lower-quality the cookie... */
-#define PKTBUF_BITS     8
-#define PKTBUF_MASK     (PKTBUF_CNT - 1)
-#define PKTBUF_CNT      (1u << PKTBUF_BITS)
-
-#define COOKIE_BITS     (32 - PKTBUF_BITS)
-#define COOKIE_MAX      ((1u << COOKIE_BITS) - 1)
-
-#define OVERWRITE_MSECS 5000
-
-struct packet {
-    struct dp_packet *buffer;
-    uint32_t cookie;
-    long long int timeout;
-    ofp_port_t in_port;
-};
-
-struct pktbuf {
-    struct packet packets[PKTBUF_CNT];
-    unsigned int buffer_idx;
-    unsigned int null_idx;
-};
-
-int
-pktbuf_capacity(void)
-{
-    return PKTBUF_CNT;
-}
-
-struct pktbuf *
-pktbuf_create(void)
-{
-    return xzalloc(sizeof *pktbuf_create());
-}
-
-void
-pktbuf_destroy(struct pktbuf *pb)
-{
-    if (pb) {
-        size_t i;
-
-        for (i = 0; i < PKTBUF_CNT; i++) {
-            dp_packet_delete(pb->packets[i].buffer);
-        }
-        free(pb);
-    }
-}
-
-static unsigned int
-make_id(unsigned int buffer_idx, unsigned int cookie)
-{
-    return buffer_idx | (cookie << PKTBUF_BITS);
-}
-
-/* Attempts to allocate an OpenFlow packet buffer id within 'pb'.  The packet
- * buffer will store a copy of 'buffer_size' bytes in 'buffer' and the port
- * number 'in_port', which should be the OpenFlow port number on which 'buffer'
- * was received.
- *
- * If successful, returns the packet buffer id (a number other than
- * UINT32_MAX).  pktbuf_retrieve() can later be used to retrieve the buffer and
- * its input port number (buffers do expire after a time, so this is not
- * guaranteed to be true forever).  On failure, returns UINT32_MAX.
- *
- * The caller retains ownership of 'buffer'. */
-uint32_t
-pktbuf_save(struct pktbuf *pb, const void *buffer, size_t buffer_size,
-            ofp_port_t in_port)
-{
-    struct packet *p = &pb->packets[pb->buffer_idx];
-    pb->buffer_idx = (pb->buffer_idx + 1) & PKTBUF_MASK;
-    if (p->buffer) {
-        if (time_msec() < p->timeout) {
-            return UINT32_MAX;
-        }
-        dp_packet_delete(p->buffer);
-    }
-
-    /* Don't use maximum cookie value since all-1-bits ID is special. */
-    if (++p->cookie >= COOKIE_MAX) {
-        p->cookie = 0;
-    }
-
-    /* Use 2 bytes of headroom to 32-bit align the L3 header. */
-    p->buffer = dp_packet_clone_data_with_headroom(buffer, buffer_size, 2);
-
-    p->timeout = time_msec() + OVERWRITE_MSECS;
-    p->in_port = in_port;
-    return make_id(p - pb->packets, p->cookie);
-}
-
-/* Attempts to retrieve a saved packet with the given 'id' from 'pb'.  Returns
- * 0 if successful, otherwise an OpenFlow error code.
- *
- * On success, stores the buffered packet in '*bufferp' and the OpenFlow port
- * number on which the packet was received in '*in_port'.  The caller becomes
- * responsible for freeing the buffer.
- *
- * 'in_port' may be NULL if the input port is not of interest.
- *
- * The L3 header of a returned packet will be 32-bit aligned.
- *
- * On failure, stores NULL in in '*bufferp' and UINT16_MAX in '*in_port'. */
-enum ofperr
-pktbuf_retrieve(struct pktbuf *pb, uint32_t id, struct dp_packet **bufferp,
-                ofp_port_t *in_port)
-{
-    static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 20);
-    struct packet *p;
-    enum ofperr error;
-
-    if (id == UINT32_MAX) {
-        error = 0;
-        goto error;
-    }
-
-    if (!pb) {
-        VLOG_WARN_RL(&rl, "attempt to send buffered packet via connection "
-                     "without buffers");
-        error = OFPERR_OFPBRC_BUFFER_UNKNOWN;
-        goto error;
-    }
-
-    p = &pb->packets[id & PKTBUF_MASK];
-    if (p->cookie == id >> PKTBUF_BITS) {
-        struct dp_packet *buffer = p->buffer;
-        if (buffer) {
-            *bufferp = buffer;
-            if (in_port) {
-                *in_port = p->in_port;
-            }
-            p->buffer = NULL;
-            COVERAGE_INC(pktbuf_retrieved);
-            return 0;
-        } else {
-            COVERAGE_INC(pktbuf_reuse_error);
-            VLOG_WARN_RL(&rl, "attempt to reuse buffer %08"PRIx32, id);
-            error = OFPERR_OFPBRC_BUFFER_EMPTY;
-        }
-    } else {
-        COVERAGE_INC(pktbuf_buffer_unknown);
-        VLOG_WARN_RL(&rl, "cookie mismatch: %08"PRIx32" != %08"PRIx32,
-                     id, (id & PKTBUF_MASK) | (p->cookie << PKTBUF_BITS));
-        error = OFPERR_OFPBRC_BUFFER_UNKNOWN;
-    }
-error:
-    *bufferp = NULL;
-    if (in_port) {
-        *in_port = OFPP_NONE;
-    }
-    return error;
-}
-
-void
-pktbuf_discard(struct pktbuf *pb, uint32_t id)
-{
-    struct packet *p = &pb->packets[id & PKTBUF_MASK];
-    if (p->cookie == id >> PKTBUF_BITS) {
-        dp_packet_delete(p->buffer);
-        p->buffer = NULL;
-    }
-}
-
-/* Returns the number of packets buffered in 'pb'.  Returns 0 if 'pb' is
- * null. */
-unsigned int
-pktbuf_count_packets(const struct pktbuf *pb)
-{
-    int n = 0;
-
-    if (pb) {
-        int i;
-
-        for (i = 0; i < PKTBUF_CNT; i++) {
-            if (pb->packets[i].buffer) {
-                n++;
-            }
-        }
-    }
-
-    return n;
-}