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ofp-parse: Allow match field names in actions and brackets in matches.

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Allow using match field names in addition to the canonical register
names in actions (including 'load', 'move', 'push', 'pop', 'output',
'multipath', 'bundle_load', and 'learn').  Allow also leaving out the
trailing '[]' to indicate full field.  These changes allow simpler
syntax similar to 'set_field' to be used also elsewhere.

Correspondingly, allow the '[start..end]' syntax to be used in matches
in addition to the more explicit 'value/mask' notation.  For example,
to match on the value 2 of the bits 14..15 of NXM_NX_REG0, the match
could include:

... reg0[14..15]=2 ...

instead of

... reg0=0x8000/0xc000 ...

Note that only contiguous masks can be specified with the bracket
notation.

Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Acked-by: Ben Pfaff <blp@ovn.org>
This commit is contained in:
Jarno Rajahalme
2017-01-04 16:10:56 -08:00
parent e7dce33f09
commit 21b2fa6171
9 changed files with 239 additions and 138 deletions
Download Patch File Download Diff File Expand all files Collapse all files

145
lib/learn.c
View File

@@ -187,24 +187,12 @@ learn_mask(const struct ofpact_learn *learn, struct flow_wildcards *wc)
/* Returns NULL if successful, otherwise a malloc()'d string describing the
* error. The caller is responsible for freeing the returned string. */
static char * OVS_WARN_UNUSED_RESULT
learn_parse_load_immediate(const char *s, struct ofpact_learn_spec *spec,
learn_parse_load_immediate(union mf_subvalue *imm, const char *s,
const char *full_s, struct ofpact_learn_spec *spec,
struct ofpbuf *ofpacts)
{
const char *full_s = s;
struct mf_subfield dst;
union mf_subvalue imm;
char *error;
int err;
err = parse_int_string(s, imm.u8, sizeof imm.u8, (char **) &s);
if (err) {
return xasprintf("%s: too many bits in immediate value", full_s);
}
if (strncmp(s, "->", 2)) {
return xasprintf("%s: missing `->' following value", full_s);
}
s += 2;
error = mf_parse_subfield(&dst, s);
if (error) {
@@ -215,8 +203,8 @@ learn_parse_load_immediate(const char *s, struct ofpact_learn_spec *spec,
full_s, s);
}
if (!bitwise_is_all_zeros(&imm, sizeof imm, dst.n_bits,
(8 * sizeof imm) - dst.n_bits)) {
if (!bitwise_is_all_zeros(imm, sizeof *imm, dst.n_bits,
(8 * sizeof *imm) - dst.n_bits)) {
return xasprintf("%s: value does not fit into %u bits",
full_s, dst.n_bits);
}
@@ -229,7 +217,7 @@ learn_parse_load_immediate(const char *s, struct ofpact_learn_spec *spec,
/* Push value last, as this may reallocate 'spec'! */
unsigned int n_bytes = DIV_ROUND_UP(dst.n_bits, 8);
uint8_t *src_imm = ofpbuf_put_zeros(ofpacts, OFPACT_ALIGN(n_bytes));
memcpy(src_imm, &imm.u8[sizeof imm.u8 - n_bytes], n_bytes);
memcpy(src_imm, &imm->u8[sizeof imm->u8 - n_bytes], n_bytes);
return NULL;
}
@@ -241,50 +229,78 @@ learn_parse_spec(const char *orig, char *name, char *value,
struct ofpact_learn_spec *spec,
struct ofpbuf *ofpacts, struct match *match)
{
if (mf_from_name(name)) {
const struct mf_field *dst = mf_from_name(name);
union mf_value imm;
char *error;
/* Parse destination and check prerequisites. */
struct mf_subfield dst;
char *error;
error = mf_parse_value(dst, value, &imm);
if (error) {
return error;
}
spec->n_bits = dst->n_bits;
spec->src_type = NX_LEARN_SRC_IMMEDIATE;
spec->dst_type = NX_LEARN_DST_MATCH;
spec->dst.field = dst;
spec->dst.ofs = 0;
spec->dst.n_bits = dst->n_bits;
/* Update 'match' to allow for satisfying destination
* prerequisites. */
mf_set_value(dst, &imm, match, NULL);
/* Push value last, as this may reallocate 'spec'! */
uint8_t *src_imm = ofpbuf_put_zeros(ofpacts,
OFPACT_ALIGN(dst->n_bytes));
memcpy(src_imm, &imm, dst->n_bytes);
} else if (strchr(name, '[')) {
/* Parse destination and check prerequisites. */
char *error;
error = mf_parse_subfield(&spec->dst, name);
if (error) {
return error;
}
if (!mf_nxm_header(spec->dst.field->id)) {
error = mf_parse_subfield(&dst, name);
if (!error) {
if (!mf_nxm_header(dst.field->id)) {
return xasprintf("%s: experimenter OXM field '%s' not supported",
orig, name);
}
spec->dst = dst;
spec->n_bits = dst.n_bits;
spec->dst_type = NX_LEARN_DST_MATCH;
/* Parse source and check prerequisites. */
if (value[0] != '\0') {
error = mf_parse_subfield(&spec->src, value);
struct mf_subfield src;
error = mf_parse_subfield(&src, value);
if (error) {
return error;
union mf_value imm;
char *imm_error = NULL;
/* Try an immediate value. */
if (dst.ofs == 0 && dst.n_bits == dst.field->n_bits) {
/* Full field value. */
imm_error = mf_parse_value(dst.field, value, &imm);
} else {
char *tail;
/* Partial field value. */
if (parse_int_string(value, (uint8_t *)&imm,
dst.field->n_bytes, &tail)
|| *tail != 0) {
imm_error = xasprintf("%s: cannot parse integer value", orig);
}
if (!imm_error &&
!bitwise_is_all_zeros(&imm, dst.field->n_bytes,
dst.n_bits,
dst.field->n_bytes * 8 - dst.n_bits)) {
struct ds ds;
ds_init(&ds);
mf_format(dst.field, &imm, NULL, &ds);
imm_error = xasprintf("%s: value %s does not fit into %d bits",
orig, ds_cstr(&ds), dst.n_bits);
ds_destroy(&ds);
}
}
if (imm_error) {
char *err = xasprintf("%s: %s value %s cannot be parsed as a subfield (%s) or an immediate value (%s)",
orig, name, value, error, imm_error);
free(error);
free(imm_error);
return err;
}
spec->src_type = NX_LEARN_SRC_IMMEDIATE;
/* Update 'match' to allow for satisfying destination
* prerequisites. */
mf_write_subfield_value(&dst, &imm, match);
/* Push value last, as this may reallocate 'spec'! */
unsigned int imm_bytes = DIV_ROUND_UP(dst.n_bits, 8);
uint8_t *src_imm = ofpbuf_put_zeros(ofpacts,
OFPACT_ALIGN(imm_bytes));
memcpy(src_imm, &imm, imm_bytes);
free(error);
return NULL;
}
spec->src = src;
if (spec->src.n_bits != spec->dst.n_bits) {
return xasprintf("%s: bit widths of %s (%u) and %s (%u) "
"differ", orig, name, spec->src.n_bits, value,
@@ -294,12 +310,29 @@ learn_parse_spec(const char *orig, char *name, char *value,
spec->src = spec->dst;
}
spec->n_bits = spec->src.n_bits;
spec->src_type = NX_LEARN_SRC_FIELD;
spec->dst_type = NX_LEARN_DST_MATCH;
} else if (!strcmp(name, "load")) {
if (value[strcspn(value, "[-")] == '-') {
char *error = learn_parse_load_immediate(value, spec, ofpacts);
union mf_subvalue imm;
char *tail;
char *dst_value = strstr(value, "->");
if (dst_value == value) {
return xasprintf("%s: missing source before `->' in `%s'", name,
value);
}
if (!dst_value) {
return xasprintf("%s: missing `->' in `%s'", name, value);
}
if (!parse_int_string(value, imm.u8, sizeof imm.u8, (char **) &tail)
&& tail != value) {
if (tail != dst_value) {
return xasprintf("%s: garbage before `->' in `%s'",
name, value);
}
char *error = learn_parse_load_immediate(&imm, dst_value + 2, value, spec,
ofpacts);
if (error) {
return error;
}