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[*] Initial commit
This commit is contained in:
Lorenzo Cogotti
237
tools/bgpgrep/bgpgrep_communities.c
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237
tools/bgpgrep/bgpgrep_communities.c
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// SPDX-License-Identifier: GPL-3.0-or-later
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/**
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* \file bgpgrep_communities.c
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*
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* COMMUNITY matching expressions parsing.
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*
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* \copyright The DoubleFourteen Code Forge (C) All Rights Reserved
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* \author Lorenzo Cogotti
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*/
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#include "bgpgrep_local.h"
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#include "sys/endian.h"
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#include "sys/fs.h"
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#include "sys/sys.h"
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#include "lexer.h"
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#include "numlib.h"
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#include "strlib.h"
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#include <assert.h>
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#include <stdlib.h>
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#include <string.h>
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#define FATALF(fmt, ...) ((void) ((lexp) ? \
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LexerError(lexp, fmt, __VA_ARGS__) : \
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Bgpgrep_Fatal("%s: " fmt, BgpgrepC_CurTerm(), __VA_ARGS__)))
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typedef struct {
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size_t cap, len;
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Bgpmatchcomm c[FLEX_ARRAY];
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} Matchcommlist;
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#define MINLISTSIZ 256
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#define LISTGROWSIZ 128
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static Boolean ParseWellKnownCommunity(Bgpmatchcomm *dest, const char *s)
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{
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if (Df_stricmp(s, "PLANNED_SHUT") == 0)
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dest->c.code = BGP_COMMUNITY_PLANNED_SHUT;
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else if (Df_stricmp(s, "ACCEPT_OWN") == 0)
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dest->c.code = BGP_COMMUNITY_ACCEPT_OWN;
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else if (Df_stricmp(s, "ROUTE_FILTER_TRANSLATED_V4") == 0)
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dest->c.code = BGP_COMMUNITY_ROUTE_FILTER_TRANSLATED_V4;
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else if (Df_stricmp(s, "ROUTE_FILTER_V4") == 0)
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dest->c.code = BGP_COMMUNITY_ROUTE_FILTER_V4;
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else if (Df_stricmp(s, "ROUTE_FILTER_TRANSLATED_V6") == 0)
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dest->c.code = BGP_COMMUNITY_ROUTE_FILTER_TRANSLATED_V6;
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else if (Df_stricmp(s, "ROUTE_FILTER_V6") == 0)
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dest->c.code = BGP_COMMUNITY_ROUTE_FILTER_V6;
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else if (Df_stricmp(s, "LLGR_STALE") == 0)
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dest->c.code = BGP_COMMUNITY_LLGR_STALE;
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else if (Df_stricmp(s, "NO_LLGR") == 0)
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dest->c.code = BGP_COMMUNITY_NO_LLGR;
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else if (Df_stricmp(s, "ACCEPT_OWN_NEXTHOP") == 0)
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dest->c.code = BGP_COMMUNITY_ACCEPT_OWN_NEXTHOP;
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else if (Df_stricmp(s, "STANDBY_PE") == 0)
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dest->c.code = BGP_COMMUNITY_STANDBY_PE;
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else if (Df_stricmp(s, "BLACKHOLE") == 0)
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dest->c.code = BGP_COMMUNITY_BLACKHOLE;
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else if (Df_stricmp(s, "NO_EXPORT") == 0)
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dest->c.code = BGP_COMMUNITY_NO_EXPORT;
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else if (Df_stricmp(s, "NO_ADVERTISE") == 0)
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dest->c.code = BGP_COMMUNITY_NO_ADVERTISE;
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else if (Df_stricmp(s, "NO_EXPORT_SUBCONFED") == 0)
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dest->c.code = BGP_COMMUNITY_NO_EXPORT_SUBCONFED;
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else if (Df_stricmp(s, "NO_PEER") == 0)
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dest->c.code = BGP_COMMUNITY_NO_PEER;
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else return FALSE;
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return TRUE;
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}
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static Bgpmatchcomm *AppendMatch(Matchcommlist **dest)
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{
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Matchcommlist *list = *dest;
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if (list->len == list->cap) {
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list->cap += LISTGROWSIZ;
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list = (Matchcommlist *) realloc(list, offsetof(Matchcommlist, c[list->cap]));
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if (!list)
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Sys_OutOfMemory();
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*dest = list;
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}
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return &list->c[list->len++];
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}
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static void ParseCommunity(Matchcommlist **dest, const char *s, Lex *lexp)
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{
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char *p = (char *) s;
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unsigned long long n;
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NumConvRet res;
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Bgpmatchcomm *m = AppendMatch(dest);
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memset(m, 0, sizeof(*m));
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if (ParseWellKnownCommunity(m, s))
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return; // got a well known community
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if (p[0] == '0' && (p[1] == 'x' || p[1] == 'X')) {
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// Hexadecimal representation
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n = Atoull(p, &p, 16, &res);
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if (res != NCVENOERR || n > 0xffffffffuLL || *p != '\0')
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FATALF("%s: Hexadecimal COMMUNITY code is out of range", s);
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m->c.code = beswap32(n);
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return;
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}
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// HIVALUE:LOVALUE (either one may be *)
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if (*p == '*') {
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m->maskHi = TRUE;
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p++;
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} else {
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n = Atoull(p, &p, 10, &res);
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if (res != NCVENOERR || n > 0xffffuLL)
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FATALF("%s: Expected numeric value or '*' for COMMUNITY high order bytes", s);
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m->c.hi = beswap16(n);
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}
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if (*p != ':')
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FATALF("%s: Expecting ':' after COMMUNITY high order bytes", s);
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p++;
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if (*p == '*') {
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m->maskLo = TRUE;
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p++;
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} else {
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n = Atoull(p, &p, 10, &res);
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if (res != NCVENOERR || n > 0xffffuLL)
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FATALF("%s: Expected numeric value or '*' for COMMUNITY low order bytes", s);
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m->c.lo = beswap16(n);
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}
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if (*p != '\0')
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FATALF("%s: Bad COMMUNITY, should be an hexadecimal code or 'hivalue:lowvalue'", s);
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if (m->maskHi && m->maskLo)
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FATALF("%s: At least one between high order or low order bytes must be defined", s);
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}
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static Judgement ParseCommunityFile(Matchcommlist **dest, const char *filename)
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{
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Lex lex;
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Tok tok;
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// Map file in memory
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Fildes fd = Sys_Fopen(filename, FM_READ, FH_SEQ);
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if (fd == FILDES_BAD)
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return NG;
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Sint64 fsiz = Sys_FileSize(fd); // NOTE: aborts on failure
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assert(fsiz >= 0);
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char *text = (char *) malloc(fsiz);
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if (!text)
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Sys_OutOfMemory();
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Sint64 n = Sys_Fread(fd, text, fsiz);
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if (n != fsiz)
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Bgpgrep_Fatal("Short read from file '%s'", filename);
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Sys_Fclose(fd);
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// Setup Lex and start reading strings
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memset(&lex, 0, sizeof(lex));
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BeginLexerSession(&lex, filename, /*line=*/1);
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SetLexerTextn(&lex, text, fsiz);
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if (!S.noColor)
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SetLexerFlags(&lex, L_COLORED);
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SetLexerErrorFunc(&lex, LEX_QUIT, LEX_WARN, NULL);
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char buf[MAXTOKLEN + 1 + MAXTOKLEN + 1];
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while (Lex_ReadToken(&lex, &tok)) {
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strcpy(buf, tok.text);
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Lex_MatchTokenType(&lex, &tok, TT_PUNCT, P_COLON);
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strcat(buf, tok.text);
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Lex_MatchAnyToken(&lex, &tok);
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strcat(buf, tok.text);
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ParseCommunity(dest, buf, &lex);
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}
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free(text);
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return OK;
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}
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Sint32 BgpgrepC_ParseCommunity(BgpVmOpt opt)
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{
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const char *tok = BgpgrepC_ExpectAnyToken();
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if (strcmp(tok, "()") == 0)
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return -1; // empty list always fails
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Matchcommlist *list = (Matchcommlist *) malloc(offsetof(Matchcommlist,
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c[MINLISTSIZ]));
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if (!list)
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Sys_OutOfMemory();
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list->cap = MINLISTSIZ;
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list->len = 0;
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if (strcmp(tok, "(") == 0) {
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// Explicit inline prefix list, directly inside command line
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while (TRUE) {
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tok = BgpgrepC_ExpectAnyToken();
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if (strcmp(tok, ")") == 0)
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break;
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ParseCommunity(&list, tok, /*lexp=*/NULL);
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}
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} else {
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// Anything else is interpreted as either:
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// - A file argument, containing a space-separated COMMUNITY match list
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// - A single match, if the file is not found
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// (shorthand for "( <community> )" )
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if (ParseCommunityFile(&list, tok) != OK)
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ParseCommunity(&list, tok, /*lexp=*/NULL);
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}
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void *match = Bgp_VmCompileCommunityMatch(&S.vm, list->c, list->len, opt);
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if (!match)
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Bgpgrep_Fatal("%s: %s", BgpgrepC_CurTerm(), Bgp_ErrorString(S.vm.errCode));
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free(list);
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Sint32 kidx = BGP_VMSETKA(&S.vm, Bgp_VmNewk(&S.vm), match);
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if (kidx == -1)
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Bgpgrep_Fatal("Too many community match expressions");
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return kidx;
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}
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