/*
- * Copyright (c) 2008, 2009 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <inttypes.h>
#include <stdlib.h>
#include "coverage.h"
+#include "ofp-util.h"
#include "ofpbuf.h"
#include "timeval.h"
#include "util.h"
#include "vconn.h"
-
-#define THIS_MODULE VLM_pktbuf
#include "vlog.h"
+VLOG_DEFINE_THIS_MODULE(pktbuf);
+
+COVERAGE_DEFINE(pktbuf_buffer_unknown);
+COVERAGE_DEFINE(pktbuf_null_cookie);
+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
struct ofpbuf *buffer;
uint32_t cookie;
long long int timeout;
- uint16_t in_port;
+ ofp_port_t in_port;
};
struct pktbuf {
struct packet packets[PKTBUF_CNT];
unsigned int buffer_idx;
+ unsigned int null_idx;
};
int
struct pktbuf *
pktbuf_create(void)
{
- return xcalloc(1, sizeof *pktbuf_create());
+ return xzalloc(sizeof *pktbuf_create());
}
void
}
}
+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, struct ofpbuf *buffer, uint16_t in_port)
+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->cookie >= COOKIE_MAX) {
p->cookie = 0;
}
- p->buffer = ofpbuf_clone(buffer);
+
+ /* Use 2 bytes of headroom to 32-bit align the L3 header. */
+ p->buffer = ofpbuf_clone_data_with_headroom(buffer, buffer_size, 2);
+
p->timeout = time_msec() + OVERWRITE_MSECS;
p->in_port = in_port;
- return (p - pb->packets) | (p->cookie << PKTBUF_BITS);
+ return make_id(p - pb->packets, p->cookie);
}
-int
+/*
+ * Allocates and returns a "null" packet buffer id. The returned packet buffer
+ * id is considered valid by pktbuf_retrieve(), but it is not associated with
+ * actual buffered data.
+ *
+ * This function is always successful.
+ *
+ * This is useful in one special case: with the current OpenFlow design, the
+ * "fail-open" code cannot always know whether a connection to a controller is
+ * actually valid until it receives a OFPT_PACKET_OUT or OFPT_FLOW_MOD request,
+ * but at that point the packet in question has already been forwarded (since
+ * we are still in "fail-open" mode). If the packet was buffered in the usual
+ * way, then the OFPT_PACKET_OUT or OFPT_FLOW_MOD would cause a duplicate
+ * packet in the network. Null packet buffer ids identify such a packet that
+ * has already been forwarded, so that Open vSwitch can quietly ignore the
+ * request to re-send it. (After that happens, the switch exits fail-open
+ * mode.)
+ *
+ * See the top-level comment in fail-open.c for an overview.
+ */
+uint32_t
+pktbuf_get_null(void)
+{
+ return make_id(0, COOKIE_MAX);
+}
+
+/* Attempts to retrieve a saved packet with the given 'id' from 'pb'. Returns
+ * 0 if successful, otherwise an OpenFlow error code.
+ *
+ * On success, ordinarily 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. However, if 'id'
+ * identifies a "null" packet buffer (created with pktbuf_get_null()), stores
+ * NULL in '*bufferp' and OFPP_NONE in '*in_port'.
+ *
+ * '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 ofpbuf **bufferp,
- uint16_t *in_port)
+ ofp_port_t *in_port)
{
static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 20);
struct packet *p;
- int error;
+ 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");
- return ofp_mkerr(OFPET_BAD_REQUEST, OFPBRC_BAD_COOKIE);
+ return OFPERR_OFPBRC_BUFFER_UNKNOWN;
}
p = &pb->packets[id & PKTBUF_MASK];
struct ofpbuf *buffer = p->buffer;
if (buffer) {
*bufferp = buffer;
- *in_port = p->in_port;
+ 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 = ofp_mkerr(OFPET_BAD_REQUEST, OFPBRC_BUFFER_EMPTY);
+ error = OFPERR_OFPBRC_BUFFER_EMPTY;
}
- } else {
- COVERAGE_INC(pktbuf_bad_cookie);
+ } else if (id >> PKTBUF_BITS != COOKIE_MAX) {
+ COVERAGE_INC(pktbuf_buffer_unknown);
VLOG_WARN_RL(&rl, "cookie mismatch: %08"PRIx32" != %08"PRIx32,
id, (id & PKTBUF_MASK) | (p->cookie << PKTBUF_BITS));
- error = ofp_mkerr(OFPET_BAD_REQUEST, OFPBRC_BAD_COOKIE);
+ error = OFPERR_OFPBRC_BUFFER_UNKNOWN;
+ } else {
+ COVERAGE_INC(pktbuf_null_cookie);
+ VLOG_INFO_RL(&rl, "Received null cookie %08"PRIx32" (this is normal "
+ "if the switch was recently in fail-open mode)", id);
+ error = 0;
}
+error:
*bufferp = NULL;
- *in_port = -1;
+ if (in_port) {
+ *in_port = OFPP_NONE;
+ }
return error;
}
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;
+}
git://git.onelab.eu / sliver-openvswitch.git / blobdiff