X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fmeta-flow.c;h=11d27b1597d3973b04611bdc02600dfc1209bea7;hb=6e492d81450217a5c90cbb4ad31d81b1e611989b;hp=41cbf4944d6f7c7337488d5d11c499ba79d8307f;hpb=28da1f8f725fc2a797174df18a7b3e31ef49ede0;p=openvswitch diff --git a/lib/meta-flow.c b/lib/meta-flow.c index 41cbf494..11d27b15 100644 --- a/lib/meta-flow.c +++ b/lib/meta-flow.c @@ -1,5 +1,5 @@ /* - * 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. @@ -26,12 +26,16 @@ #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, \ @@ -87,6 +91,15 @@ static const struct mf_field mf_fields[MFF_N_IDS] = { REGISTER(4), #endif #if FLOW_N_REGS > 5 + REGISTER(5), +#endif +#if FLOW_N_REGS > 6 + REGISTER(6), +#endif +#if FLOW_N_REGS > 7 + REGISTER(7), +#endif +#if FLOW_N_REGS > 8 #error #endif @@ -286,7 +299,7 @@ static const struct mf_field mf_fields[MFF_N_IDS] = { { MFF_TCP_SRC, "tcp_src", "tp_src", MF_FIELD_SIZES(be16), - MFM_NONE, FWW_TP_SRC, + MFM_FULLY, 0, MFS_DECIMAL, MFP_TCP, true, @@ -294,7 +307,7 @@ static const struct mf_field mf_fields[MFF_N_IDS] = { }, { MFF_TCP_DST, "tcp_dst", "tp_dst", MF_FIELD_SIZES(be16), - MFM_NONE, FWW_TP_DST, + MFM_FULLY, 0, MFS_DECIMAL, MFP_TCP, true, @@ -304,7 +317,7 @@ static const struct mf_field mf_fields[MFF_N_IDS] = { { MFF_UDP_SRC, "udp_src", NULL, MF_FIELD_SIZES(be16), - MFM_NONE, FWW_TP_SRC, + MFM_FULLY, 0, MFS_DECIMAL, MFP_UDP, true, @@ -312,7 +325,7 @@ static const struct mf_field mf_fields[MFF_N_IDS] = { }, { MFF_UDP_DST, "udp_dst", NULL, MF_FIELD_SIZES(be16), - MFM_NONE, FWW_TP_DST, + MFM_FULLY, 0, MFS_DECIMAL, MFP_UDP, true, @@ -322,7 +335,7 @@ static const struct mf_field mf_fields[MFF_N_IDS] = { { MFF_ICMPV4_TYPE, "icmp_type", NULL, MF_FIELD_SIZES(u8), - MFM_NONE, FWW_TP_SRC, + MFM_NONE, 0, MFS_DECIMAL, MFP_ICMPV4, false, @@ -330,7 +343,7 @@ static const struct mf_field mf_fields[MFF_N_IDS] = { }, { MFF_ICMPV4_CODE, "icmp_code", NULL, MF_FIELD_SIZES(u8), - MFM_NONE, FWW_TP_DST, + MFM_NONE, 0, MFS_DECIMAL, MFP_ICMPV4, false, @@ -340,7 +353,7 @@ static const struct mf_field mf_fields[MFF_N_IDS] = { { MFF_ICMPV6_TYPE, "icmpv6_type", NULL, MF_FIELD_SIZES(u8), - MFM_NONE, FWW_TP_SRC, + MFM_NONE, 0, MFS_DECIMAL, MFP_ICMPV6, false, @@ -348,7 +361,7 @@ static const struct mf_field mf_fields[MFF_N_IDS] = { }, { MFF_ICMPV6_CODE, "icmpv6_code", NULL, MF_FIELD_SIZES(u8), - MFM_NONE, FWW_TP_DST, + MFM_NONE, 0, MFS_DECIMAL, MFP_ICMPV6, false, @@ -394,6 +407,10 @@ struct nxm_field { 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) @@ -501,14 +518,6 @@ mf_is_all_wild(const struct mf_field *mf, const struct flow_wildcards *wc) case MFF_ARP_OP: case MFF_ARP_SHA: case MFF_ARP_THA: - case MFF_TCP_SRC: - case MFF_TCP_DST: - case MFF_UDP_SRC: - case MFF_UDP_DST: - case MFF_ICMPV4_TYPE: - case MFF_ICMPV4_CODE: - case MFF_ICMPV6_TYPE: - case MFF_ICMPV6_CODE: case MFF_ND_TARGET: case MFF_ND_SLL: case MFF_ND_TLL: @@ -534,6 +543,15 @@ mf_is_all_wild(const struct mf_field *mf, const struct flow_wildcards *wc) case MFF_REG4: #endif #if FLOW_N_REGS > 5 + case MFF_REG5: +#endif +#if FLOW_N_REGS > 6 + case MFF_REG6: +#endif +#if FLOW_N_REGS > 7 + case MFF_REG7: +#endif +#if FLOW_N_REGS > 8 #error #endif return !wc->reg_masks[mf->id - MFF_REG0]; @@ -567,6 +585,17 @@ mf_is_all_wild(const struct mf_field *mf, const struct flow_wildcards *wc) case MFF_ARP_TPA: return !wc->nw_dst_mask; + case MFF_TCP_SRC: + case MFF_UDP_SRC: + case MFF_ICMPV4_TYPE: + case MFF_ICMPV6_TYPE: + return !wc->tp_src_mask; + case MFF_TCP_DST: + case MFF_UDP_DST: + case MFF_ICMPV4_CODE: + case MFF_ICMPV6_CODE: + return !wc->tp_dst_mask; + case MFF_N_IDS: default: NOT_REACHED(); @@ -595,14 +624,6 @@ mf_get_mask(const struct mf_field *mf, const struct flow_wildcards *wc, case MFF_ARP_OP: case MFF_ARP_SHA: case MFF_ARP_THA: - case MFF_TCP_SRC: - case MFF_TCP_DST: - case MFF_UDP_SRC: - case MFF_UDP_DST: - case MFF_ICMPV4_TYPE: - case MFF_ICMPV4_CODE: - case MFF_ICMPV6_TYPE: - case MFF_ICMPV6_CODE: case MFF_ND_TARGET: case MFF_ND_SLL: case MFF_ND_TLL: @@ -630,6 +651,15 @@ mf_get_mask(const struct mf_field *mf, const struct flow_wildcards *wc, case MFF_REG4: #endif #if FLOW_N_REGS > 5 + case MFF_REG5: +#endif +#if FLOW_N_REGS > 6 + case MFF_REG6: +#endif +#if FLOW_N_REGS > 7 + case MFF_REG7: +#endif +#if FLOW_N_REGS > 8 #error #endif mask->be32 = htonl(wc->reg_masks[mf->id - MFF_REG0]); @@ -675,6 +705,24 @@ mf_get_mask(const struct mf_field *mf, const struct flow_wildcards *wc, mask->be32 = wc->nw_dst_mask; break; + case MFF_TCP_SRC: + case MFF_UDP_SRC: + mask->be16 = wc->tp_src_mask; + break; + case MFF_TCP_DST: + case MFF_UDP_DST: + mask->be16 = wc->tp_dst_mask; + break; + + case MFF_ICMPV4_TYPE: + case MFF_ICMPV6_TYPE: + mask->u8 = ntohs(wc->tp_src_mask); + break; + case MFF_ICMPV4_CODE: + case MFF_ICMPV6_CODE: + mask->u8 = ntohs(wc->tp_dst_mask); + break; + case MFF_N_IDS: default: NOT_REACHED(); @@ -803,6 +851,15 @@ mf_is_value_valid(const struct mf_field *mf, const union mf_value *value) case MFF_REG4: #endif #if FLOW_N_REGS > 5 + case MFF_REG5: +#endif +#if FLOW_N_REGS > 6 + case MFF_REG6: +#endif +#if FLOW_N_REGS > 7 + case MFF_REG7: +#endif +#if FLOW_N_REGS > 8 #error #endif case MFF_ETH_SRC: @@ -888,6 +945,15 @@ mf_get_value(const struct mf_field *mf, const struct flow *flow, case MFF_REG4: #endif #if FLOW_N_REGS > 5 + case MFF_REG5: +#endif +#if FLOW_N_REGS > 6 + case MFF_REG6: +#endif +#if FLOW_N_REGS > 7 + case MFF_REG7: +#endif +#if FLOW_N_REGS > 8 #error #endif value->be32 = htonl(flow->regs[mf->id - MFF_REG0]); @@ -1047,6 +1113,15 @@ mf_set_value(const struct mf_field *mf, case MFF_REG4: #endif #if FLOW_N_REGS > 5 + case MFF_REG5: +#endif +#if FLOW_N_REGS > 6 + case MFF_REG6: +#endif +#if FLOW_N_REGS > 7 + case MFF_REG7: +#endif +#if FLOW_N_REGS > 8 #error #endif #if FLOW_N_REGS > 0 @@ -1208,6 +1283,15 @@ mf_set_flow_value(const struct mf_field *mf, case MFF_REG4: #endif #if FLOW_N_REGS > 5 + case MFF_REG5: +#endif +#if FLOW_N_REGS > 6 + case MFF_REG6: +#endif +#if FLOW_N_REGS > 7 + case MFF_REG7: +#endif +#if FLOW_N_REGS > 8 #error #endif #if FLOW_N_REGS > 0 @@ -1376,6 +1460,21 @@ mf_set_wild(const struct mf_field *mf, struct cls_rule *rule) break; #endif #if FLOW_N_REGS > 5 + case MFF_REG5: + cls_rule_set_reg_masked(rule, 5, 0, 0); + break; +#endif +#if FLOW_N_REGS > 6 + case MFF_REG6: + cls_rule_set_reg_masked(rule, 6, 0, 0); + break; +#endif +#if FLOW_N_REGS > 7 + case MFF_REG7: + cls_rule_set_reg_masked(rule, 7, 0, 0); + break; +#endif +#if FLOW_N_REGS > 8 #error #endif @@ -1477,7 +1576,7 @@ mf_set_wild(const struct mf_field *mf, struct cls_rule *rule) case MFF_UDP_SRC: case MFF_ICMPV4_TYPE: case MFF_ICMPV6_TYPE: - rule->wc.wildcards |= FWW_TP_SRC; + rule->wc.tp_src_mask = htons(0); rule->flow.tp_src = htons(0); break; @@ -1485,7 +1584,7 @@ mf_set_wild(const struct mf_field *mf, struct cls_rule *rule) case MFF_UDP_DST: case MFF_ICMPV4_CODE: case MFF_ICMPV6_CODE: - rule->wc.wildcards |= FWW_TP_DST; + rule->wc.tp_dst_mask = htons(0); rule->flow.tp_dst = htons(0); break; @@ -1538,10 +1637,6 @@ mf_set(const struct mf_field *mf, case MFF_ARP_OP: case MFF_ARP_SHA: case MFF_ARP_THA: - case MFF_TCP_SRC: - case MFF_TCP_DST: - case MFF_UDP_SRC: - case MFF_UDP_DST: case MFF_ICMPV4_TYPE: case MFF_ICMPV4_CODE: case MFF_ICMPV6_TYPE: @@ -1571,6 +1666,15 @@ mf_set(const struct mf_field *mf, case MFF_REG4: #endif #if FLOW_N_REGS > 5 + case MFF_REG5: +#endif +#if FLOW_N_REGS > 6 + case MFF_REG6: +#endif +#if FLOW_N_REGS > 7 + case MFF_REG7: +#endif +#if FLOW_N_REGS > 8 #error #endif cls_rule_set_reg_masked(rule, mf->id - MFF_REG0, @@ -1615,83 +1719,69 @@ mf_set(const struct mf_field *mf, cls_rule_set_nw_dst_masked(rule, value->be32, mask->be32); break; + case MFF_TCP_SRC: + case MFF_UDP_SRC: + cls_rule_set_tp_src_masked(rule, value->be16, mask->be16); + break; + + case MFF_TCP_DST: + case MFF_UDP_DST: + cls_rule_set_tp_dst_masked(rule, value->be16, mask->be16); + break; + case MFF_N_IDS: default: NOT_REACHED(); } } -/* 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 @@ -1729,6 +1819,15 @@ mf_random_value(const struct mf_field *mf, union mf_value *value) case MFF_REG4: #endif #if FLOW_N_REGS > 5 + case MFF_REG5: +#endif +#if FLOW_N_REGS > 6 + case MFF_REG6: +#endif +#if FLOW_N_REGS > 7 + case MFF_REG7: +#endif +#if FLOW_N_REGS > 8 #error #endif case MFF_ETH_SRC: @@ -2141,3 +2240,222 @@ mf_format(const struct mf_field *mf, NOT_REACHED(); } } + +/* 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, ""); + } 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->field && 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 [] or " + "[..]", *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; +}