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ofp-actions: Centralize all OpenFlow action code for maintainability.

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Until now, knowledge about OpenFlow has been somewhat scattered around the
tree.  Some of it is in ofp-actions, some of it is in ofp-util, some in
separate files for individual actions, and most of the wire format
declarations are in include/openflow.  This commit centralizes all of that
in ofp-actions.

Encoding and decoding OpenFlow actions was previously broken up by OpenFlow
version.  This was OK with only OpenFlow 1.0 and 1.1, but each additional
version added a new wrapper around the existing ones, which started to
become hard to understand.  This commit merges all of the processing for
the different versions, to the extent that they are similar, making the
version differences clearer.

Previously, ofp-actions contained OpenFlow encoding and decoding, plus
ofpact formatting, but OpenFlow parsing was separated into ofp-parse, which
seems an odd division.  This commit moves the parsing code into ofp-actions
with the rest of the code.

Before this commit, the four main bits of code associated with a particular
ofpact--OpenFlow encoding and decoding, ofpact formatting and parsing--were
all found far away from each other.  This often made it hard to see what
was going on for a particular ofpact, since you had to search around to
many different pieces of code.  This commit reorganizes so that all of the
code for a given ofpact is in a single place.

As a code refactoring, this commit has little visible behavioral change.
The update to ofproto-dpif.at illustrates one minor bug fix as a side
effect: a flow that was added with the action "dec_ttl" (a standard
OpenFlow action) was previously formatted as "dec_ttl(0)" (using a Nicira
extension to specifically direct packets bounced to the controller because
of too-low TTL), but after this commit it is correctly formatted as
"dec_ttl".

The other visible effect is to drop support for the Nicira extension
dec_ttl action in OpenFlow 1.1 and later in favor of the equivalent
standard action.  It seems unlikely that anyone was really using the
Nicira extension in OF1.1 or later.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
This commit is contained in:
Ben Pfaff
2014-08-11 12:50:36 -07:00
parent 8f2cded496
commit c2d936a44f
28 changed files with 5023 additions and 5417 deletions
Download Patch File Download Diff File Expand all files Collapse all files

212
lib/learn.c
View File

@@ -30,145 +30,6 @@
#include "openflow/openflow.h"
#include "unaligned.h"
static ovs_be16
get_be16(const void **pp)
{
const ovs_be16 *p = *pp;
ovs_be16 value = *p;
*pp = p + 1;
return value;
}
static ovs_be32
get_be32(const void **pp)
{
const ovs_be32 *p = *pp;
ovs_be32 value = get_unaligned_be32(p);
*pp = p + 1;
return value;
}
static void
get_subfield(int n_bits, const void **p, struct mf_subfield *sf)
{
sf->field = mf_from_nxm_header(ntohl(get_be32(p)));
sf->ofs = ntohs(get_be16(p));
sf->n_bits = n_bits;
}
static unsigned int
learn_min_len(uint16_t header)
{
int n_bits = header & NX_LEARN_N_BITS_MASK;
int src_type = header & NX_LEARN_SRC_MASK;
int dst_type = header & NX_LEARN_DST_MASK;
unsigned int min_len;
min_len = 0;
if (src_type == NX_LEARN_SRC_FIELD) {
min_len += sizeof(ovs_be32); /* src_field */
min_len += sizeof(ovs_be16); /* src_ofs */
} else {
min_len += DIV_ROUND_UP(n_bits, 16);
}
if (dst_type == NX_LEARN_DST_MATCH ||
dst_type == NX_LEARN_DST_LOAD) {
min_len += sizeof(ovs_be32); /* dst_field */
min_len += sizeof(ovs_be16); /* dst_ofs */
}
return min_len;
}
/* Converts 'nal' into a "struct ofpact_learn" and appends that struct to
* 'ofpacts'. Returns 0 if successful, otherwise an OFPERR_*. */
enum ofperr
learn_from_openflow(const struct nx_action_learn *nal, struct ofpbuf *ofpacts)
{
struct ofpact_learn *learn;
const void *p, *end;
if (nal->pad) {
return OFPERR_OFPBAC_BAD_ARGUMENT;
}
learn = ofpact_put_LEARN(ofpacts);
learn->idle_timeout = ntohs(nal->idle_timeout);
learn->hard_timeout = ntohs(nal->hard_timeout);
learn->priority = ntohs(nal->priority);
learn->cookie = nal->cookie;
learn->table_id = nal->table_id;
learn->fin_idle_timeout = ntohs(nal->fin_idle_timeout);
learn->fin_hard_timeout = ntohs(nal->fin_hard_timeout);
learn->flags = ntohs(nal->flags);
if (learn->flags & ~(NX_LEARN_F_SEND_FLOW_REM |
NX_LEARN_F_DELETE_LEARNED)) {
return OFPERR_OFPBAC_BAD_ARGUMENT;
}
if (learn->table_id == 0xff) {
return OFPERR_OFPBAC_BAD_ARGUMENT;
}
end = (char *) nal + ntohs(nal->len);
for (p = nal + 1; p != end; ) {
struct ofpact_learn_spec *spec;
uint16_t header = ntohs(get_be16(&p));
if (!header) {
break;
}
spec = ofpbuf_put_zeros(ofpacts, sizeof *spec);
learn = ofpacts->frame;
learn->n_specs++;
spec->src_type = header & NX_LEARN_SRC_MASK;
spec->dst_type = header & NX_LEARN_DST_MASK;
spec->n_bits = header & NX_LEARN_N_BITS_MASK;
/* Check for valid src and dst type combination. */
if (spec->dst_type == NX_LEARN_DST_MATCH ||
spec->dst_type == NX_LEARN_DST_LOAD ||
(spec->dst_type == NX_LEARN_DST_OUTPUT &&
spec->src_type == NX_LEARN_SRC_FIELD)) {
/* OK. */
} else {
return OFPERR_OFPBAC_BAD_ARGUMENT;
}
/* Check that the arguments don't overrun the end of the action. */
if ((char *) end - (char *) p < learn_min_len(header)) {
return OFPERR_OFPBAC_BAD_LEN;
}
/* Get the source. */
if (spec->src_type == NX_LEARN_SRC_FIELD) {
get_subfield(spec->n_bits, &p, &spec->src);
} else {
int p_bytes = 2 * DIV_ROUND_UP(spec->n_bits, 16);
bitwise_copy(p, p_bytes, 0,
&spec->src_imm, sizeof spec->src_imm, 0,
spec->n_bits);
p = (const uint8_t *) p + p_bytes;
}
/* Get the destination. */
if (spec->dst_type == NX_LEARN_DST_MATCH ||
spec->dst_type == NX_LEARN_DST_LOAD) {
get_subfield(spec->n_bits, &p, &spec->dst);
}
}
ofpact_update_len(ofpacts, &learn->ofpact);
if (!is_all_zeros(p, (char *) end - (char *) p)) {
return OFPERR_OFPBAC_BAD_ARGUMENT;
}
return 0;
}
/* Checks that 'learn' is a valid action on 'flow'. Returns 0 if it is valid,
* otherwise an OFPERR_*. */
@@ -216,79 +77,6 @@ learn_check(const struct ofpact_learn *learn, const struct flow *flow)
return 0;
}
static void
put_be16(struct ofpbuf *b, ovs_be16 x)
{
ofpbuf_put(b, &x, sizeof x);
}
static void
put_be32(struct ofpbuf *b, ovs_be32 x)
{
ofpbuf_put(b, &x, sizeof x);
}
static void
put_u16(struct ofpbuf *b, uint16_t x)
{
put_be16(b, htons(x));
}
static void
put_u32(struct ofpbuf *b, uint32_t x)
{
put_be32(b, htonl(x));
}
/* Converts 'learn' into a "struct nx_action_learn" and appends that action to
* 'ofpacts'. */
void
learn_to_nxast(const struct ofpact_learn *learn, struct ofpbuf *openflow)
{
const struct ofpact_learn_spec *spec;
struct nx_action_learn *nal;
size_t start_ofs;
start_ofs = ofpbuf_size(openflow);
nal = ofputil_put_NXAST_LEARN(openflow);
nal->idle_timeout = htons(learn->idle_timeout);
nal->hard_timeout = htons(learn->hard_timeout);
nal->fin_idle_timeout = htons(learn->fin_idle_timeout);
nal->fin_hard_timeout = htons(learn->fin_hard_timeout);
nal->priority = htons(learn->priority);
nal->cookie = learn->cookie;
nal->flags = htons(learn->flags);
nal->table_id = learn->table_id;
for (spec = learn->specs; spec < &learn->specs[learn->n_specs]; spec++) {
put_u16(openflow, spec->n_bits | spec->dst_type | spec->src_type);
if (spec->src_type == NX_LEARN_SRC_FIELD) {
put_u32(openflow, spec->src.field->nxm_header);
put_u16(openflow, spec->src.ofs);
} else {
size_t n_dst_bytes = 2 * DIV_ROUND_UP(spec->n_bits, 16);
uint8_t *bits = ofpbuf_put_zeros(openflow, n_dst_bytes);
bitwise_copy(&spec->src_imm, sizeof spec->src_imm, 0,
bits, n_dst_bytes, 0,
spec->n_bits);
}
if (spec->dst_type == NX_LEARN_DST_MATCH ||
spec->dst_type == NX_LEARN_DST_LOAD) {
put_u32(openflow, spec->dst.field->nxm_header);
put_u16(openflow, spec->dst.ofs);
}
}
if ((ofpbuf_size(openflow) - start_ofs) % 8) {
ofpbuf_put_zeros(openflow, 8 - (ofpbuf_size(openflow) - start_ofs) % 8);
}
nal = ofpbuf_at_assert(openflow, start_ofs, sizeof *nal);
nal->len = htons(ofpbuf_size(openflow) - start_ofs);
}
/* Composes 'fm' so that executing it will implement 'learn' given that the
* packet being processed has 'flow' as its flow.
*