/*
- * Copyright (c) 2011 Nicira Networks.
+ * Copyright (c) 2011, 2012 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include "classifier.h"
#include "dynamic-string.h"
+#include "ofp-errors.h"
#include "ofp-util.h"
#include "packets.h"
#include "random.h"
#include "shash.h"
#include "socket-util.h"
#include "unaligned.h"
+#include "vlog.h"
+
+VLOG_DEFINE_THIS_MODULE(meta_flow);
#define MF_FIELD_SIZES(MEMBER) \
sizeof ((union mf_value *)0)->MEMBER, \
static struct hmap all_nxm_fields = HMAP_INITIALIZER(&all_nxm_fields);
+/* Rate limit for parse errors. These always indicate a bug in an OpenFlow
+ * controller and so there's not much point in showing a lot of them. */
+static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
+
/* Returns the field with the given 'id'. */
const struct mf_field *
mf_from_id(enum mf_field_id id)
}
}
-/* Makes a subfield starting at bit offset 'ofs' and continuing for 'n_bits' in
- * 'rule''s field 'mf' exactly match the 'n_bits' least-significant bits of
- * 'x'.
- *
- * Example: suppose that 'mf' is originally the following 2-byte field in
- * 'rule':
- *
- * value == 0xe00a == 2#1110000000001010
- * mask == 0xfc3f == 2#1111110000111111
- *
- * The call mf_set_subfield(mf, 0x55, 8, 7, rule) would have the following
- * effect (note that 0x55 is 2#1010101):
- *
- * value == 0xd50a == 2#1101010100001010
- * mask == 0xff3f == 2#1111111100111111
- *
- * The caller is responsible for ensuring that the result will be a valid
- * wildcard pattern for 'mf'. The caller is responsible for ensuring that
- * 'rule' meets 'mf''s prerequisites. */
-void
-mf_set_subfield(const struct mf_field *mf, uint64_t x, unsigned int ofs,
- unsigned int n_bits, struct cls_rule *rule)
+static enum ofperr
+mf_check__(const struct mf_subfield *sf, const struct flow *flow,
+ const char *type)
{
- if (ofs == 0 && mf->n_bytes * 8 == n_bits) {
- union mf_value value;
- int i;
-
- for (i = mf->n_bytes - 1; i >= 0; i--) {
- ((uint8_t *) &value)[i] = x;
- x >>= 8;
- }
- mf_set_value(mf, &value, rule);
+ if (!sf->field) {
+ VLOG_WARN_RL(&rl, "unknown %s field", type);
+ } else if (!sf->n_bits) {
+ VLOG_WARN_RL(&rl, "zero bit %s field %s", type, sf->field->name);
+ } else if (sf->ofs >= sf->field->n_bits) {
+ VLOG_WARN_RL(&rl, "bit offset %d exceeds %d-bit width of %s field %s",
+ sf->ofs, sf->field->n_bits, type, sf->field->name);
+ } else if (sf->ofs + sf->n_bits > sf->field->n_bits) {
+ VLOG_WARN_RL(&rl, "bit offset %d and width %d exceeds %d-bit width "
+ "of %s field %s", sf->ofs, sf->n_bits,
+ sf->field->n_bits, type, sf->field->name);
+ } else if (flow && !mf_are_prereqs_ok(sf->field, flow)) {
+ VLOG_WARN_RL(&rl, "%s field %s lacks correct prerequisites",
+ type, sf->field->name);
} else {
- union mf_value value, mask;
- uint8_t *vp, *mp;
- unsigned int byte_ofs;
-
- mf_get(mf, rule, &value, &mask);
-
- byte_ofs = mf->n_bytes - ofs / 8;
- vp = &((uint8_t *) &value)[byte_ofs];
- mp = &((uint8_t *) &mask)[byte_ofs];
- if (ofs % 8) {
- unsigned int chunk = MIN(8 - ofs % 8, n_bits);
- uint8_t chunk_mask = ((1 << chunk) - 1) << (ofs % 8);
-
- *--vp &= ~chunk_mask;
- *vp |= chunk_mask & (x << (ofs % 8));
- *--mp |= chunk_mask;
+ return 0;
+ }
- x >>= chunk;
- n_bits -= chunk;
- ofs += chunk;
- }
- while (n_bits >= 8) {
- *--vp = x;
- *--mp = 0xff;
- x >>= 8;
- n_bits -= 8;
- ofs += 8;
- }
- if (n_bits) {
- uint8_t chunk_mask = (1 << n_bits) - 1;
+ return OFPERR_OFPBAC_BAD_ARGUMENT;
+}
- *--vp &= ~chunk_mask;
- *vp |= chunk_mask & x;
- *--mp |= chunk_mask;
- }
+/* Checks whether 'sf' is valid for reading a subfield out of 'flow'. Returns
+ * 0 if so, otherwise an OpenFlow error code (e.g. as returned by
+ * ofp_mkerr()). */
+enum ofperr
+mf_check_src(const struct mf_subfield *sf, const struct flow *flow)
+{
+ return mf_check__(sf, flow, "source");
+}
- mf_set(mf, &value, &mask, rule);
+/* Checks whether 'sf' is valid for writing a subfield into 'flow'. Returns 0
+ * if so, otherwise an OpenFlow error code (e.g. as returned by
+ * ofp_mkerr()). */
+enum ofperr
+mf_check_dst(const struct mf_subfield *sf, const struct flow *flow)
+{
+ int error = mf_check__(sf, flow, "destination");
+ if (!error && !sf->field->writable) {
+ VLOG_WARN_RL(&rl, "destination field %s is not writable",
+ sf->field->name);
+ return OFPERR_OFPBAC_BAD_ARGUMENT;
}
+ return error;
}
/* Copies the value and wildcard bit pattern for 'mf' from 'rule' into the
NOT_REACHED();
}
}
+\f
+/* Makes a subfield starting at bit offset 'ofs' and continuing for 'n_bits' in
+ * 'rule''s field 'mf' exactly match the 'n_bits' least-significant bits of
+ * 'x'.
+ *
+ * Example: suppose that 'mf' is originally the following 2-byte field in
+ * 'rule':
+ *
+ * value == 0xe00a == 2#1110000000001010
+ * mask == 0xfc3f == 2#1111110000111111
+ *
+ * The call mf_set_subfield(mf, 0x55, 8, 7, rule) would have the following
+ * effect (note that 0x55 is 2#1010101):
+ *
+ * value == 0xd50a == 2#1101010100001010
+ * mask == 0xff3f == 2#1111111100111111
+ *
+ * The caller is responsible for ensuring that the result will be a valid
+ * wildcard pattern for 'mf'. The caller is responsible for ensuring that
+ * 'rule' meets 'mf''s prerequisites. */
+void
+mf_set_subfield(const struct mf_subfield *sf, uint64_t x,
+ struct cls_rule *rule)
+{
+ const struct mf_field *field = sf->field;
+ unsigned int n_bits = sf->n_bits;
+ unsigned int ofs = sf->ofs;
+
+ if (ofs == 0 && field->n_bytes * 8 == n_bits) {
+ union mf_value value;
+ int i;
+
+ for (i = field->n_bytes - 1; i >= 0; i--) {
+ ((uint8_t *) &value)[i] = x;
+ x >>= 8;
+ }
+ mf_set_value(field, &value, rule);
+ } else {
+ union mf_value value, mask;
+ uint8_t *vp = (uint8_t *) &value;
+ uint8_t *mp = (uint8_t *) &mask;
+
+ mf_get(field, rule, &value, &mask);
+ bitwise_put(x, vp, field->n_bytes, ofs, n_bits);
+ bitwise_put(UINT64_MAX, mp, field->n_bytes, ofs, n_bits);
+ mf_set(field, &value, &mask, rule);
+ }
+}
+
+/* Similar to mf_set_subfield() but modifies only a flow, not a cls_rule. */
+void
+mf_set_subfield_value(const struct mf_subfield *sf, uint64_t x,
+ struct flow *flow)
+{
+ const struct mf_field *field = sf->field;
+ unsigned int n_bits = sf->n_bits;
+ unsigned int ofs = sf->ofs;
+ union mf_value value;
+
+ if (ofs == 0 && field->n_bytes * 8 == n_bits) {
+ int i;
+
+ for (i = field->n_bytes - 1; i >= 0; i--) {
+ ((uint8_t *) &value)[i] = x;
+ x >>= 8;
+ }
+ mf_set_flow_value(field, &value, flow);
+ } else {
+ mf_get_value(field, flow, &value);
+ bitwise_put(x, &value, field->n_bytes, ofs, n_bits);
+ mf_set_flow_value(field, &value, flow);
+ }
+}
+
+/* Returns the value of 'sf' within 'flow'. 'sf' must be valid for reading
+ * 'flow', e.g. as checked by mf_check_src() and sf->n_bits must be 64 or
+ * less. */
+uint64_t
+mf_get_subfield(const struct mf_subfield *sf, const struct flow *flow)
+{
+ union mf_value value;
+
+ mf_get_value(sf->field, flow, &value);
+ return bitwise_get(&value, sf->field->n_bytes, sf->ofs, sf->n_bits);
+}
+
+/* Formats 'sf' into 's' in a format normally acceptable to
+ * mf_parse_subfield(). (It won't be acceptable if sf->field is NULL or if
+ * sf->field has no NXM name.) */
+void
+mf_format_subfield(const struct mf_subfield *sf, struct ds *s)
+{
+ if (!sf->field) {
+ ds_put_cstr(s, "<unknown>");
+ } else if (sf->field->nxm_name) {
+ ds_put_cstr(s, sf->field->nxm_name);
+ } else if (sf->field->nxm_header) {
+ uint32_t header = sf->field->nxm_header;
+ ds_put_format(s, "%d:%d", NXM_VENDOR(header), NXM_FIELD(header));
+ } else {
+ ds_put_cstr(s, sf->field->name);
+ }
+
+ if (sf->ofs == 0 && sf->n_bits == sf->field->n_bits) {
+ ds_put_cstr(s, "[]");
+ } else if (sf->n_bits == 1) {
+ ds_put_format(s, "[%d]", sf->ofs);
+ } else {
+ ds_put_format(s, "[%d..%d]", sf->ofs, sf->ofs + sf->n_bits - 1);
+ }
+}
+
+static const struct mf_field *
+mf_parse_subfield_name(const char *name, int name_len, bool *wild)
+{
+ int i;
+
+ *wild = name_len > 2 && !memcmp(&name[name_len - 2], "_W", 2);
+ if (*wild) {
+ name_len -= 2;
+ }
+
+ for (i = 0; i < MFF_N_IDS; i++) {
+ const struct mf_field *mf = mf_from_id(i);
+
+ if (mf->nxm_name
+ && !strncmp(mf->nxm_name, name, name_len)
+ && mf->nxm_name[name_len] == '\0') {
+ return mf;
+ }
+ }
+
+ return NULL;
+}
+
+/* Parses a subfield from the beginning of '*sp' into 'sf'. If successful,
+ * returns NULL and advances '*sp' to the first byte following the parsed
+ * string. On failure, returns a malloc()'d error message, does not modify
+ * '*sp', and does not properly initialize 'sf'.
+ *
+ * The syntax parsed from '*sp' takes the form "header[start..end]" where
+ * 'header' is the name of an NXM field and 'start' and 'end' are (inclusive)
+ * bit indexes. "..end" may be omitted to indicate a single bit. "start..end"
+ * may both be omitted (the [] are still required) to indicate an entire
+ * field. */
+char *
+mf_parse_subfield__(struct mf_subfield *sf, const char **sp)
+{
+ const struct mf_field *field;
+ const char *name;
+ int start, end;
+ const char *s;
+ int name_len;
+ bool wild;
+
+ s = *sp;
+ name = s;
+ name_len = strcspn(s, "[");
+ if (s[name_len] != '[') {
+ return xasprintf("%s: missing [ looking for field name", *sp);
+ }
+
+ field = mf_parse_subfield_name(name, name_len, &wild);
+ if (!field) {
+ return xasprintf("%s: unknown field `%.*s'", *sp, name_len, s);
+ }
+
+ s += name_len;
+ if (sscanf(s, "[%d..%d]", &start, &end) == 2) {
+ /* Nothing to do. */
+ } else if (sscanf(s, "[%d]", &start) == 1) {
+ end = start;
+ } else if (!strncmp(s, "[]", 2)) {
+ start = 0;
+ end = field->n_bits - 1;
+ } else {
+ return xasprintf("%s: syntax error expecting [] or [<bit>] or "
+ "[<start>..<end>]", *sp);
+ }
+ s = strchr(s, ']') + 1;
+
+ if (start > end) {
+ return xasprintf("%s: starting bit %d is after ending bit %d",
+ *sp, start, end);
+ } else if (start >= field->n_bits) {
+ return xasprintf("%s: starting bit %d is not valid because field is "
+ "only %d bits wide", *sp, start, field->n_bits);
+ } else if (end >= field->n_bits){
+ return xasprintf("%s: ending bit %d is not valid because field is "
+ "only %d bits wide", *sp, end, field->n_bits);
+ }
+
+ sf->field = field;
+ sf->ofs = start;
+ sf->n_bits = end - start + 1;
+
+ *sp = s;
+ return NULL;
+}
+
+/* Parses a subfield from the beginning of 's' into 'sf'. Returns the first
+ * byte in 's' following the parsed string.
+ *
+ * Exits with an error message if 's' has incorrect syntax.
+ *
+ * The syntax parsed from 's' takes the form "header[start..end]" where
+ * 'header' is the name of an NXM field and 'start' and 'end' are (inclusive)
+ * bit indexes. "..end" may be omitted to indicate a single bit. "start..end"
+ * may both be omitted (the [] are still required) to indicate an entire
+ * field. */
+const char *
+mf_parse_subfield(struct mf_subfield *sf, const char *s)
+{
+ char *msg = mf_parse_subfield__(sf, &s);
+ if (msg) {
+ ovs_fatal(0, "%s", msg);
+ }
+ return s;
+}