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author | peter <peter@FreeBSD.org> | 2008-07-12 05:00:28 +0000 |
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committer | peter <peter@FreeBSD.org> | 2008-07-12 05:00:28 +0000 |
commit | ba8f85b49c38af7bc2a9acdef5dcde2de008d25e (patch) | |
tree | ceac31a567976fd5866cb5791b059781f6e045de /lib/bind/irs/hesiod.c | |
parent | 0f328cea2580ffb8f9e363be671a517787111472 (diff) | |
download | FreeBSD-src-ba8f85b49c38af7bc2a9acdef5dcde2de008d25e.zip FreeBSD-src-ba8f85b49c38af7bc2a9acdef5dcde2de008d25e.tar.gz |
Flatten bind9 vendor work area
Diffstat (limited to 'lib/bind/irs/hesiod.c')
-rw-r--r-- | lib/bind/irs/hesiod.c | 505 |
1 files changed, 505 insertions, 0 deletions
diff --git a/lib/bind/irs/hesiod.c b/lib/bind/irs/hesiod.c new file mode 100644 index 0000000..5abb57c --- /dev/null +++ b/lib/bind/irs/hesiod.c @@ -0,0 +1,505 @@ +#if defined(LIBC_SCCS) && !defined(lint) +static const char rcsid[] = "$Id: hesiod.c,v 1.4.18.3 2005/07/28 07:38:08 marka Exp $"; +#endif + +/* + * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") + * Copyright (c) 1996,1999 by Internet Software Consortium. + * + * 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 ISC DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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. + */ + + +/*! \file + * \brief + * hesiod.c --- the core portion of the hesiod resolver. + * + * This file is derived from the hesiod library from Project Athena; + * It has been extensively rewritten by Theodore Ts'o to have a more + * thread-safe interface. + * \author + * This file is primarily maintained by <tytso@mit.edu> and <ghudson@mit.edu>. + */ + +/* Imports */ + +#include "port_before.h" + +#include <sys/types.h> +#include <netinet/in.h> +#include <arpa/nameser.h> + +#include <errno.h> +#include <netdb.h> +#include <resolv.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "port_after.h" + +#include "pathnames.h" +#include "hesiod.h" +#include "hesiod_p.h" + +/* Forward */ + +int hesiod_init(void **context); +void hesiod_end(void *context); +char * hesiod_to_bind(void *context, const char *name, + const char *type); +char ** hesiod_resolve(void *context, const char *name, + const char *type); +void hesiod_free_list(void *context, char **list); + +static int parse_config_file(struct hesiod_p *ctx, const char *filename); +static char ** get_txt_records(struct hesiod_p *ctx, int class, + const char *name); +static int init(struct hesiod_p *ctx); + +/* Public */ + +/*% + * This function is called to initialize a hesiod_p. + */ +int +hesiod_init(void **context) { + struct hesiod_p *ctx; + char *cp; + + ctx = malloc(sizeof(struct hesiod_p)); + if (ctx == 0) { + errno = ENOMEM; + return (-1); + } + + memset(ctx, 0, sizeof (*ctx)); + + if (parse_config_file(ctx, _PATH_HESIOD_CONF) < 0) { +#ifdef DEF_RHS + /* + * Use compiled in defaults. + */ + ctx->LHS = malloc(strlen(DEF_LHS) + 1); + ctx->RHS = malloc(strlen(DEF_RHS) + 1); + if (ctx->LHS == NULL || ctx->RHS == NULL) { + errno = ENOMEM; + goto cleanup; + } + strcpy(ctx->LHS, DEF_LHS); /* (checked) */ + strcpy(ctx->RHS, DEF_RHS); /* (checked) */ +#else + goto cleanup; +#endif + } + /* + * The default RHS can be overridden by an environment + * variable. + */ + if ((cp = getenv("HES_DOMAIN")) != NULL) { + size_t RHSlen = strlen(cp) + 2; + if (ctx->RHS) + free(ctx->RHS); + ctx->RHS = malloc(RHSlen); + if (!ctx->RHS) { + errno = ENOMEM; + goto cleanup; + } + if (cp[0] == '.') { + strcpy(ctx->RHS, cp); /* (checked) */ + } else { + strcpy(ctx->RHS, "."); /* (checked) */ + strcat(ctx->RHS, cp); /* (checked) */ + } + } + + /* + * If there is no default hesiod realm set, we return an + * error. + */ + if (!ctx->RHS) { + errno = ENOEXEC; + goto cleanup; + } + +#if 0 + if (res_ninit(ctx->res) < 0) + goto cleanup; +#endif + + *context = ctx; + return (0); + + cleanup: + hesiod_end(ctx); + return (-1); +} + +/*% + * This function deallocates the hesiod_p + */ +void +hesiod_end(void *context) { + struct hesiod_p *ctx = (struct hesiod_p *) context; + int save_errno = errno; + + if (ctx->res) + res_nclose(ctx->res); + if (ctx->RHS) + free(ctx->RHS); + if (ctx->LHS) + free(ctx->LHS); + if (ctx->res && ctx->free_res) + (*ctx->free_res)(ctx->res); + free(ctx); + errno = save_errno; +} + +/*% + * This function takes a hesiod (name, type) and returns a DNS + * name which is to be resolved. + */ +char * +hesiod_to_bind(void *context, const char *name, const char *type) { + struct hesiod_p *ctx = (struct hesiod_p *) context; + char *bindname; + char **rhs_list = NULL; + const char *RHS, *cp; + + /* Decide what our RHS is, and set cp to the end of the actual name. */ + if ((cp = strchr(name, '@')) != NULL) { + if (strchr(cp + 1, '.')) + RHS = cp + 1; + else if ((rhs_list = hesiod_resolve(context, cp + 1, + "rhs-extension")) != NULL) + RHS = *rhs_list; + else { + errno = ENOENT; + return (NULL); + } + } else { + RHS = ctx->RHS; + cp = name + strlen(name); + } + + /* + * Allocate the space we need, including up to three periods and + * the terminating NUL. + */ + if ((bindname = malloc((cp - name) + strlen(type) + strlen(RHS) + + (ctx->LHS ? strlen(ctx->LHS) : 0) + 4)) == NULL) { + errno = ENOMEM; + if (rhs_list) + hesiod_free_list(context, rhs_list); + return NULL; + } + + /* Now put together the DNS name. */ + memcpy(bindname, name, cp - name); + bindname[cp - name] = '\0'; + strcat(bindname, "."); + strcat(bindname, type); + if (ctx->LHS) { + if (ctx->LHS[0] != '.') + strcat(bindname, "."); + strcat(bindname, ctx->LHS); + } + if (RHS[0] != '.') + strcat(bindname, "."); + strcat(bindname, RHS); + + if (rhs_list) + hesiod_free_list(context, rhs_list); + + return (bindname); +} + +/*% + * This is the core function. Given a hesiod (name, type), it + * returns an array of strings returned by the resolver. + */ +char ** +hesiod_resolve(void *context, const char *name, const char *type) { + struct hesiod_p *ctx = (struct hesiod_p *) context; + char *bindname = hesiod_to_bind(context, name, type); + char **retvec; + + if (bindname == NULL) + return (NULL); + if (init(ctx) == -1) { + free(bindname); + return (NULL); + } + + if ((retvec = get_txt_records(ctx, C_IN, bindname))) { + free(bindname); + return (retvec); + } + + if (errno != ENOENT) + return (NULL); + + retvec = get_txt_records(ctx, C_HS, bindname); + free(bindname); + return (retvec); +} + +void +hesiod_free_list(void *context, char **list) { + char **p; + + UNUSED(context); + + for (p = list; *p; p++) + free(*p); + free(list); +} + +/*% + * This function parses the /etc/hesiod.conf file + */ +static int +parse_config_file(struct hesiod_p *ctx, const char *filename) { + char *key, *data, *cp, **cpp; + char buf[MAXDNAME+7]; + FILE *fp; + + /* + * Clear the existing configuration variable, just in case + * they're set. + */ + if (ctx->RHS) + free(ctx->RHS); + if (ctx->LHS) + free(ctx->LHS); + ctx->RHS = ctx->LHS = 0; + + /* + * Now open and parse the file... + */ + if (!(fp = fopen(filename, "r"))) + return (-1); + + while (fgets(buf, sizeof(buf), fp) != NULL) { + cp = buf; + if (*cp == '#' || *cp == '\n' || *cp == '\r') + continue; + while(*cp == ' ' || *cp == '\t') + cp++; + key = cp; + while(*cp != ' ' && *cp != '\t' && *cp != '=') + cp++; + *cp++ = '\0'; + + while(*cp == ' ' || *cp == '\t' || *cp == '=') + cp++; + data = cp; + while(*cp != ' ' && *cp != '\n' && *cp != '\r') + cp++; + *cp++ = '\0'; + + if (strcmp(key, "lhs") == 0) + cpp = &ctx->LHS; + else if (strcmp(key, "rhs") == 0) + cpp = &ctx->RHS; + else + continue; + + *cpp = malloc(strlen(data) + 1); + if (!*cpp) { + errno = ENOMEM; + goto cleanup; + } + strcpy(*cpp, data); + } + fclose(fp); + return (0); + + cleanup: + fclose(fp); + if (ctx->RHS) + free(ctx->RHS); + if (ctx->LHS) + free(ctx->LHS); + ctx->RHS = ctx->LHS = 0; + return (-1); +} + +/*% + * Given a DNS class and a DNS name, do a lookup for TXT records, and + * return a list of them. + */ +static char ** +get_txt_records(struct hesiod_p *ctx, int class, const char *name) { + struct { + int type; /*%< RR type */ + int class; /*%< RR class */ + int dlen; /*%< len of data section */ + u_char *data; /*%< pointer to data */ + } rr; + HEADER *hp; + u_char qbuf[MAX_HESRESP], abuf[MAX_HESRESP]; + u_char *cp, *erdata, *eom; + char *dst, *edst, **list; + int ancount, qdcount; + int i, j, n, skip; + + /* + * Construct the query and send it. + */ + n = res_nmkquery(ctx->res, QUERY, name, class, T_TXT, NULL, 0, + NULL, qbuf, MAX_HESRESP); + if (n < 0) { + errno = EMSGSIZE; + return (NULL); + } + n = res_nsend(ctx->res, qbuf, n, abuf, MAX_HESRESP); + if (n < 0) { + errno = ECONNREFUSED; + return (NULL); + } + if (n < HFIXEDSZ) { + errno = EMSGSIZE; + return (NULL); + } + + /* + * OK, parse the result. + */ + hp = (HEADER *) abuf; + ancount = ntohs(hp->ancount); + qdcount = ntohs(hp->qdcount); + cp = abuf + sizeof(HEADER); + eom = abuf + n; + + /* Skip query, trying to get to the answer section which follows. */ + for (i = 0; i < qdcount; i++) { + skip = dn_skipname(cp, eom); + if (skip < 0 || cp + skip + QFIXEDSZ > eom) { + errno = EMSGSIZE; + return (NULL); + } + cp += skip + QFIXEDSZ; + } + + list = malloc((ancount + 1) * sizeof(char *)); + if (!list) { + errno = ENOMEM; + return (NULL); + } + j = 0; + for (i = 0; i < ancount; i++) { + skip = dn_skipname(cp, eom); + if (skip < 0) { + errno = EMSGSIZE; + goto cleanup; + } + cp += skip; + if (cp + 3 * INT16SZ + INT32SZ > eom) { + errno = EMSGSIZE; + goto cleanup; + } + rr.type = ns_get16(cp); + cp += INT16SZ; + rr.class = ns_get16(cp); + cp += INT16SZ + INT32SZ; /*%< skip the ttl, too */ + rr.dlen = ns_get16(cp); + cp += INT16SZ; + if (cp + rr.dlen > eom) { + errno = EMSGSIZE; + goto cleanup; + } + rr.data = cp; + cp += rr.dlen; + if (rr.class != class || rr.type != T_TXT) + continue; + if (!(list[j] = malloc(rr.dlen))) + goto cleanup; + dst = list[j++]; + edst = dst + rr.dlen; + erdata = rr.data + rr.dlen; + cp = rr.data; + while (cp < erdata) { + n = (unsigned char) *cp++; + if (cp + n > eom || dst + n > edst) { + errno = EMSGSIZE; + goto cleanup; + } + memcpy(dst, cp, n); + cp += n; + dst += n; + } + if (cp != erdata) { + errno = EMSGSIZE; + goto cleanup; + } + *dst = '\0'; + } + list[j] = NULL; + if (j == 0) { + errno = ENOENT; + goto cleanup; + } + return (list); + + cleanup: + for (i = 0; i < j; i++) + free(list[i]); + free(list); + return (NULL); +} + +struct __res_state * +__hesiod_res_get(void *context) { + struct hesiod_p *ctx = context; + + if (!ctx->res) { + struct __res_state *res; + res = (struct __res_state *)malloc(sizeof *res); + if (res == NULL) { + errno = ENOMEM; + return (NULL); + } + memset(res, 0, sizeof *res); + __hesiod_res_set(ctx, res, free); + } + + return (ctx->res); +} + +void +__hesiod_res_set(void *context, struct __res_state *res, + void (*free_res)(void *)) { + struct hesiod_p *ctx = context; + + if (ctx->res && ctx->free_res) { + res_nclose(ctx->res); + (*ctx->free_res)(ctx->res); + } + + ctx->res = res; + ctx->free_res = free_res; +} + +static int +init(struct hesiod_p *ctx) { + + if (!ctx->res && !__hesiod_res_get(ctx)) + return (-1); + + if (((ctx->res->options & RES_INIT) == 0U) && + (res_ninit(ctx->res) == -1)) + return (-1); + + return (0); +} |