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IABSD.fr/src/sbin/unwind/parse.y
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- sbin/unwind/parse.y
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/* $OpenBSD: parse.y,v 1.32 2026/02/26 18:46:57 jcs Exp $ */ /* * Copyright (c) 2018 Florian Obser <florian@openbsd.org> * Copyright (c) 2004, 2005 Esben Norby <norby@openbsd.org> * Copyright (c) 2004 Ryan McBride <mcbride@openbsd.org> * Copyright (c) 2002, 2003, 2004 Henning Brauer <henning@openbsd.org> * Copyright (c) 2001 Markus Friedl. All rights reserved. * Copyright (c) 2001 Daniel Hartmeier. All rights reserved. * Copyright (c) 2001 Theo de Raadt. All rights reserved. * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ %{ #include <sys/queue.h> #include <sys/socket.h> #include <sys/stat.h> #include <sys/types.h> #include <ctype.h> #include <err.h> #include <errno.h> #include <limits.h> #include <netdb.h> #include <stdarg.h> #include <stdint.h> #include <stdio.h> #include <syslog.h> #include <unistd.h> #include "log.h" #include "unwind.h" TAILQ_HEAD(files, file) files = TAILQ_HEAD_INITIALIZER(files); static struct file { TAILQ_ENTRY(file) entry; FILE *stream; char *name; size_t ungetpos; size_t ungetsize; u_char *ungetbuf; int eof_reached; int lineno; int errors; } *file, *topfile; struct file *pushfile(const char *, int); int popfile(void); int check_file_secrecy(int, const char *); int yyparse(void); int yylex(void); int yyerror(const char *, ...) __attribute__((__format__ (printf, 1, 2))) __attribute__((__nonnull__ (1))); int kw_cmp(const void *, const void *); int lookup(char *); int igetc(void); int lgetc(int); void lungetc(int); int findeol(void); TAILQ_HEAD(symhead, sym) symhead = TAILQ_HEAD_INITIALIZER(symhead); struct sym { TAILQ_ENTRY(sym) entry; int used; int persist; char *nam; char *val; }; int symset(const char *, const char *, int); char *symget(const char *); int check_pref_uniq(enum uw_resolver_type); static struct uw_conf *conf; static int errors; void clear_config(struct uw_conf *xconf); struct sockaddr_storage *host_ip(const char *); typedef struct { union { int64_t number; char *string; struct force_tree force; } v; int lineno; } YYSTYPE; %} %token INCLUDE ERROR %token FORWARDER DOT PORT ODOT_FORWARDER ODOT_AUTOCONF ODOT_DHCP %token AUTHENTICATION NAME PREFERENCE RECURSOR AUTOCONF DHCP STUB %token BLOCK LIST LOG FORCE ACCEPT BOGUS %token <v.string> STRING %token <v.number> NUMBER %type <v.number> port dot prefopt log acceptbogus %type <v.string> string authname %type <v.force> force_list %% grammar : /* empty */ | grammar include '\n' | grammar '\n' | grammar varset '\n' | grammar uw_pref '\n' | grammar uw_forwarder '\n' | grammar block_list '\n' | grammar force '\n' | grammar error '\n' { file->errors++; } ; include : INCLUDE STRING { struct file *nfile; if ((nfile = pushfile($2, 0)) == NULL) { yyerror("failed to include file %s", $2); free($2); YYERROR; } free($2); file = nfile; lungetc('\n'); } ; string : string STRING { if (asprintf(&$$, "%s %s", $1, $2) == -1) { free($1); free($2); yyerror("string: asprintf"); YYERROR; } free($1); free($2); } | STRING ; varset : STRING '=' string { char *s = $1; if (cmd_opts & OPT_VERBOSE) printf("%s = \"%s\"\n", $1, $3); while (*s++) { if (isspace((unsigned char)*s)) { yyerror("macro name cannot contain " "whitespace"); free($1); free($3); YYERROR; } } if (symset($1, $3, 0) == -1) fatal("cannot store variable"); free($1); free($3); } ; optnl : '\n' optnl /* zero or more newlines */ | /*empty*/ ; block_list : BLOCK LIST STRING log { if (conf->blocklist_file != NULL) { yyerror("block list already " "configured"); free($3); YYERROR; } else { conf->blocklist_file = strdup($3); if (conf->blocklist_file == NULL) err(1, "strdup"); free($3); conf->blocklist_log = $4; } } ; uw_pref : PREFERENCE { conf->res_pref.len = 0; memset(conf->enabled_resolvers, 0, sizeof(conf->enabled_resolvers)); } pref_block ; pref_block : '{' optnl prefopts_l '}' | prefoptsl ; prefopts_l : prefopts_l prefoptsl optnl | prefoptsl optnl ; prefoptsl : prefopt { if (!check_pref_uniq($1)) YYERROR; if (conf->res_pref.len >= UW_RES_NONE) { yyerror("preference list too long"); YYERROR; } conf->res_pref.types[conf->res_pref.len++] = $1; conf->enabled_resolvers[$1] = 1; } ; prefopt : DOT { $$ = UW_RES_DOT; } | FORWARDER { $$ = UW_RES_FORWARDER; } | ODOT_FORWARDER { $$ = UW_RES_ODOT_FORWARDER; } | RECURSOR { $$ = UW_RES_RECURSOR; } | AUTOCONF { $$ = UW_RES_AUTOCONF; } | DHCP { $$ = UW_RES_AUTOCONF; } | ODOT_AUTOCONF { $$ = UW_RES_ODOT_AUTOCONF; } | ODOT_DHCP { $$ = UW_RES_ODOT_AUTOCONF; } | STUB { $$ = UW_RES_ASR; } ; uw_forwarder : FORWARDER forwarder_block ; forwarder_block : '{' optnl forwarderopts_l '}' | forwarderoptsl ; forwarderopts_l : forwarderopts_l forwarderoptsl optnl | forwarderoptsl optnl ; forwarderoptsl : STRING port authname dot { struct uw_forwarder *uw_fwd; struct sockaddr_storage *ss; if ((ss = host_ip($1)) == NULL) { yyerror("%s is not an ip-address", $1); free($1); YYERROR; } free(ss); if ((uw_fwd = calloc(1, sizeof(*uw_fwd))) == NULL) err(1, NULL); if ($2 < 0 || $2 > (int)USHRT_MAX) { yyerror("invalid port: %lld", $2); free($1); free(uw_fwd); YYERROR; } if ($2 == 0) uw_fwd->port = $4 == DOT ? 853 : 53; else uw_fwd->port = $2; if ($3 != NULL && $4 == 0) { yyerror("authentication name can only " "be used with DoT"); free($1); free(uw_fwd); YYERROR; } if (strlcpy(uw_fwd->ip, $1, sizeof(uw_fwd->ip)) >= sizeof(uw_fwd->ip)) { free(uw_fwd); yyerror("forwarder %s too long", $1); free($1); YYERROR; } if ($4 == DOT && $3 != NULL) { if (strlcpy(uw_fwd->auth_name, $3, sizeof(uw_fwd->auth_name)) >= sizeof(uw_fwd->auth_name)) { free(uw_fwd); yyerror("authentication name " "%s too long", $3); free($1); YYERROR; } } if ($4 == DOT) TAILQ_INSERT_TAIL( &conf->uw_dot_forwarder_list, uw_fwd, entry); else { TAILQ_INSERT_TAIL( &conf->uw_forwarder_list, uw_fwd, entry); } free($1); } ; port : PORT NUMBER { $$ = $2; } | /* empty */ { $$ = 0; } ; authname: AUTHENTICATION NAME STRING { $$ = $3; } | /* empty */ { $$ = NULL; } ; dot : DOT { $$ = DOT; } | /* empty */ { $$ = 0; } ; log : LOG { $$ = 1; } | /* empty */ { $$ = 0; } ; force : FORCE acceptbogus prefopt '{' force_list optnl '}' { struct force_tree_entry *n, *nxt; int error = 0; RB_FOREACH_SAFE(n, force_tree, &$5, nxt) { n->acceptbogus = $2; n->type = $3; conf->force_resolvers[$3] = 1; conf->enabled_resolvers[$3] = 1; RB_REMOVE(force_tree, &$5, n); if (RB_INSERT(force_tree, &conf->force, n)) { yyerror("%s already in a force " "list", n->domain); error = 1; } } if (error) YYERROR; } ; acceptbogus: ACCEPT BOGUS { $$ = 1; } | /* empty */ { $$ = 0; } ; force_list: force_list optnl STRING { struct force_tree_entry *e; size_t len; len = strlen($3); e = calloc(1, sizeof(*e)); if (e == NULL) err(1, NULL); if (strlcpy(e->domain, $3, sizeof(e->domain)) >= sizeof(e->domain)) { yyerror("force %s too long", $3); free($3); YYERROR; } free($3); if (len == 0 || e->domain[len-1] != '.') { if (strlcat(e->domain, ".", sizeof((e->domain))) >= sizeof((e->domain))) { yyerror("force %s too long", $3); YYERROR; } } if (RB_INSERT(force_tree, &$$, e) != NULL) { log_warnx("duplicate force %s", e->domain); free(e); } } | /* empty */ { RB_INIT(&$$); } ; %% struct keywords { const char *k_name; int k_val; }; int yyerror(const char *fmt, ...) { va_list ap; char *msg; file->errors++; va_start(ap, fmt); if (vasprintf(&msg, fmt, ap) == -1) fatalx("yyerror vasprintf"); va_end(ap); logit(LOG_CRIT, "%s:%d: %s", file->name, yylval.lineno, msg); free(msg); return (0); } int kw_cmp(const void *k, const void *e) { return (strcmp(k, ((const struct keywords *)e)->k_name)); } int lookup(char *s) { /* This has to be sorted always. */ static const struct keywords keywords[] = { {"DoT", DOT}, {"accept", ACCEPT}, {"authentication", AUTHENTICATION}, {"autoconf", AUTOCONF}, {"block", BLOCK}, {"bogus", BOGUS}, {"dhcp", DHCP}, {"dot", DOT}, {"force", FORCE}, {"forwarder", FORWARDER}, {"include", INCLUDE}, {"list", LIST}, {"log", LOG}, {"name", NAME}, {"oDoT-autoconf", ODOT_AUTOCONF}, {"oDoT-dhcp", ODOT_DHCP}, {"oDoT-forwarder", ODOT_FORWARDER}, {"port", PORT}, {"preference", PREFERENCE}, {"recursor", RECURSOR}, {"stub", STUB}, {"tls", DOT}, }; const struct keywords *p; p = bsearch(s, keywords, sizeof(keywords)/sizeof(keywords[0]), sizeof(keywords[0]), kw_cmp); if (p) return (p->k_val); else return (STRING); } #define START_EXPAND 1 #define DONE_EXPAND 2 static int expanding; int igetc(void) { int c; while (1) { if (file->ungetpos > 0) c = file->ungetbuf[--file->ungetpos]; else c = getc(file->stream); if (c == START_EXPAND) expanding = 1; else if (c == DONE_EXPAND) expanding = 0; else break; } return (c); } int lgetc(int quotec) { int c, next; if (quotec) { if ((c = igetc()) == EOF) { yyerror("reached end of file while parsing " "quoted string"); if (file == topfile || popfile() == EOF) return (EOF); return (quotec); } return (c); } while ((c = igetc()) == '\\') { next = igetc(); if (next != '\n') { c = next; break; } yylval.lineno = file->lineno; file->lineno++; } if (c == EOF) { /* * Fake EOL when hit EOF for the first time. This gets line * count right if last line in included file is syntactically * invalid and has no newline. */ if (file->eof_reached == 0) { file->eof_reached = 1; return ('\n'); } while (c == EOF) { if (file == topfile || popfile() == EOF) return (EOF); c = igetc(); } } return (c); } void lungetc(int c) { if (c == EOF) return; if (file->ungetpos >= file->ungetsize) { void *p = reallocarray(file->ungetbuf, file->ungetsize, 2); if (p == NULL) err(1, "lungetc"); file->ungetbuf = p; file->ungetsize *= 2; } file->ungetbuf[file->ungetpos++] = c; } int findeol(void) { int c; /* Skip to either EOF or the first real EOL. */ while (1) { c = lgetc(0); if (c == '\n') { file->lineno++; break; } if (c == EOF) break; } return (ERROR); } int yylex(void) { char buf[8096]; char *p, *val; int quotec, next, c; int token; top: p = buf; while ((c = lgetc(0)) == ' ' || c == '\t') ; /* nothing */ yylval.lineno = file->lineno; if (c == '#') while ((c = lgetc(0)) != '\n' && c != EOF) ; /* nothing */ if (c == '$' && !expanding) { while (1) { if ((c = lgetc(0)) == EOF) return (0); if (p + 1 >= buf + sizeof(buf) - 1) { yyerror("string too long"); return (findeol()); } if (isalnum(c) || c == '_') { *p++ = c; continue; } *p = '\0'; lungetc(c); break; } val = symget(buf); if (val == NULL) { yyerror("macro '%s' not defined", buf); return (findeol()); } p = val + strlen(val) - 1; lungetc(DONE_EXPAND); while (p >= val) { lungetc((unsigned char)*p); p--; } lungetc(START_EXPAND); goto top; } switch (c) { case '\'': case '"': quotec = c; while (1) { if ((c = lgetc(quotec)) == EOF) return (0); if (c == '\n') { file->lineno++; continue; } else if (c == '\\') { if ((next = lgetc(quotec)) == EOF) return (0); if (next == quotec || next == ' ' || next == '\t') c = next; else if (next == '\n') { file->lineno++; continue; } else lungetc(next); } else if (c == quotec) { *p = '\0'; break; } else if (c == '\0') { yyerror("syntax error"); return (findeol()); } if (p + 1 >= buf + sizeof(buf) - 1) { yyerror("string too long"); return (findeol()); } *p++ = c; } yylval.v.string = strdup(buf); if (yylval.v.string == NULL) err(1, "yylex: strdup"); return (STRING); } #define allowed_to_end_number(x) \ (isspace(x) || x == ')' || x ==',' || x == '/' || x == '}' || x == '=') if (c == '-' || isdigit(c)) { do { *p++ = c; if ((size_t)(p-buf) >= sizeof(buf)) { yyerror("string too long"); return (findeol()); } } while ((c = lgetc(0)) != EOF && isdigit(c)); lungetc(c); if (p == buf + 1 && buf[0] == '-') goto nodigits; if (c == EOF || allowed_to_end_number(c)) { const char *errstr = NULL; *p = '\0'; yylval.v.number = strtonum(buf, LLONG_MIN, LLONG_MAX, &errstr); if (errstr) { yyerror("\"%s\" invalid number: %s", buf, errstr); return (findeol()); } return (NUMBER); } else { nodigits: while (p > buf + 1) lungetc((unsigned char)*--p); c = (unsigned char)*--p; if (c == '-') return (c); } } #define allowed_in_string(x) \ (isalnum(x) || (ispunct(x) && x != '(' && x != ')' && \ x != '{' && x != '}' && \ x != '!' && x != '=' && x != '#' && \ x != ',')) if (isalnum(c) || c == ':' || c == '_') { do { *p++ = c; if ((size_t)(p-buf) >= sizeof(buf)) { yyerror("string too long"); return (findeol()); } } while ((c = lgetc(0)) != EOF && (allowed_in_string(c))); lungetc(c); *p = '\0'; if ((token = lookup(buf)) == STRING) if ((yylval.v.string = strdup(buf)) == NULL) err(1, "yylex: strdup"); return (token); } if (c == '\n') { yylval.lineno = file->lineno; file->lineno++; } if (c == EOF) return (0); return (c); } int check_file_secrecy(int fd, const char *fname) { struct stat st; if (fstat(fd, &st)) { log_warn("cannot stat %s", fname); return (-1); } if (st.st_uid != 0 && st.st_uid != getuid()) { log_warnx("%s: owner not root or current user", fname); return (-1); } if (st.st_mode & (S_IWGRP | S_IXGRP | S_IRWXO)) { log_warnx("%s: group writable or world read/writable", fname); return (-1); } return (0); } struct file * pushfile(const char *name, int secret) { struct file *nfile; if ((nfile = calloc(1, sizeof(struct file))) == NULL) { log_warn("calloc"); return (NULL); } if ((nfile->name = strdup(name)) == NULL) { log_warn("strdup"); free(nfile); return (NULL); } if ((nfile->stream = fopen(nfile->name, "r")) == NULL) { free(nfile->name); free(nfile); return (NULL); } else if (secret && check_file_secrecy(fileno(nfile->stream), nfile->name)) { fclose(nfile->stream); free(nfile->name); free(nfile); return (NULL); } nfile->lineno = TAILQ_EMPTY(&files) ? 1 : 0; nfile->ungetsize = 16; nfile->ungetbuf = malloc(nfile->ungetsize); if (nfile->ungetbuf == NULL) { log_warn("malloc"); fclose(nfile->stream); free(nfile->name); free(nfile); return (NULL); } TAILQ_INSERT_TAIL(&files, nfile, entry); return (nfile); } int popfile(void) { struct file *prev; if ((prev = TAILQ_PREV(file, files, entry)) != NULL) prev->errors += file->errors; TAILQ_REMOVE(&files, file, entry); fclose(file->stream); free(file->name); free(file->ungetbuf); free(file); file = prev; return (file ? 0 : EOF); } struct uw_conf * parse_config(char *filename) { static enum uw_resolver_type default_res_pref[] = { UW_RES_DOT, UW_RES_ODOT_FORWARDER, UW_RES_FORWARDER, UW_RES_RECURSOR, UW_RES_ODOT_AUTOCONF, UW_RES_AUTOCONF, UW_RES_ASR}; struct sym *sym, *next; int i; conf = config_new_empty(); memcpy(&conf->res_pref.types, &default_res_pref, sizeof(default_res_pref)); conf->res_pref.len = nitems(default_res_pref); for (i = 0; i < conf->res_pref.len; i++) conf->enabled_resolvers[conf->res_pref.types[i]] = 1; file = pushfile(filename != NULL ? filename : _PATH_CONF_FILE, 0); if (file == NULL) { /* no default config file is fine */ if (errno == ENOENT && filename == NULL) return (conf); log_warn("%s", filename); free(conf); return (NULL); } topfile = file; yyparse(); errors = file->errors; popfile(); /* Free macros and check which have not been used. */ TAILQ_FOREACH_SAFE(sym, &symhead, entry, next) { if ((cmd_opts & OPT_VERBOSE2) && !sym->used) fprintf(stderr, "warning: macro '%s' not used\n", sym->nam); if (!sym->persist) { free(sym->nam); free(sym->val); TAILQ_REMOVE(&symhead, sym, entry); free(sym); } } if (errors) { clear_config(conf); return (NULL); } return (conf); } int symset(const char *nam, const char *val, int persist) { struct sym *sym; TAILQ_FOREACH(sym, &symhead, entry) { if (strcmp(nam, sym->nam) == 0) break; } if (sym != NULL) { if (sym->persist == 1) return (0); else { free(sym->nam); free(sym->val); TAILQ_REMOVE(&symhead, sym, entry); free(sym); } } if ((sym = calloc(1, sizeof(*sym))) == NULL) return (-1); sym->nam = strdup(nam); if (sym->nam == NULL) { free(sym); return (-1); } sym->val = strdup(val); if (sym->val == NULL) { free(sym->nam); free(sym); return (-1); } sym->used = 0; sym->persist = persist; TAILQ_INSERT_TAIL(&symhead, sym, entry); return (0); } int cmdline_symset(char *s) { char *sym, *val; int ret; if ((val = strrchr(s, '=')) == NULL) return (-1); sym = strndup(s, val - s); if (sym == NULL) errx(1, "%s: strndup", __func__); ret = symset(sym, val + 1, 1); free(sym); return (ret); } char * symget(const char *nam) { struct sym *sym; TAILQ_FOREACH(sym, &symhead, entry) { if (strcmp(nam, sym->nam) == 0) { sym->used = 1; return (sym->val); } } return (NULL); } void clear_config(struct uw_conf *xconf) { struct uw_forwarder *uw_forwarder; while ((uw_forwarder = TAILQ_FIRST(&xconf->uw_forwarder_list)) != NULL) { TAILQ_REMOVE(&xconf->uw_forwarder_list, uw_forwarder, entry); free(uw_forwarder); } while ((uw_forwarder = TAILQ_FIRST(&xconf->uw_dot_forwarder_list)) != NULL) { TAILQ_REMOVE(&xconf->uw_dot_forwarder_list, uw_forwarder, entry); free(uw_forwarder); } free(xconf); } struct sockaddr_storage * host_ip(const char *s) { struct addrinfo hints, *res; struct sockaddr_storage *ss = NULL; memset(&hints, 0, sizeof(hints)); hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_DGRAM; /*dummy*/ hints.ai_flags = AI_NUMERICHOST; if (getaddrinfo(s, "0", &hints, &res) == 0) { if (res->ai_family == AF_INET || res->ai_family == AF_INET6) { if ((ss = calloc(1, sizeof(*ss))) == NULL) fatal(NULL); memcpy(ss, res->ai_addr, res->ai_addrlen); } freeaddrinfo(res); } return (ss); } int check_pref_uniq(enum uw_resolver_type type) { int i; for (i = 0; i < conf->res_pref.len; i++) if (conf->res_pref.types[i] == type) { yyerror("%s is already in the preference list", uw_resolver_type_str[type]); return (0); } return (1); }