diff options
Diffstat (limited to 'REORG.TODO/nss/nss_files/files-hosts.c')
-rw-r--r-- | REORG.TODO/nss/nss_files/files-hosts.c | 482 |
1 files changed, 482 insertions, 0 deletions
diff --git a/REORG.TODO/nss/nss_files/files-hosts.c b/REORG.TODO/nss/nss_files/files-hosts.c new file mode 100644 index 0000000000..bccb6a5780 --- /dev/null +++ b/REORG.TODO/nss/nss_files/files-hosts.c @@ -0,0 +1,482 @@ +/* Hosts file parser in nss_files module. + Copyright (C) 1996-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <assert.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <arpa/nameser.h> +#include <netdb.h> +#include <resolv/resolv-internal.h> + + +/* Get implementation for some internal functions. */ +#include "../resolv/mapv4v6addr.h" +#include "../resolv/res_hconf.h" + + +#define ENTNAME hostent +#define DATABASE "hosts" +#define NEED_H_ERRNO + +#define EXTRA_ARGS , af, flags +#define EXTRA_ARGS_DECL , int af, int flags + +#define ENTDATA hostent_data +struct hostent_data + { + unsigned char host_addr[16]; /* IPv4 or IPv6 address. */ + char *h_addr_ptrs[2]; /* Points to that and null terminator. */ + }; + +#define TRAILING_LIST_MEMBER h_aliases +#define TRAILING_LIST_SEPARATOR_P isspace +#include "files-parse.c" +LINE_PARSER +("#", + { + char *addr; + + STRING_FIELD (addr, isspace, 1); + + /* Parse address. */ + if (inet_pton (af == AF_UNSPEC ? AF_INET : af, addr, entdata->host_addr) + > 0) + af = af == AF_UNSPEC ? AF_INET : af; + else + { + if (af == AF_INET6 && (flags & AI_V4MAPPED) != 0 + && inet_pton (AF_INET, addr, entdata->host_addr) > 0) + map_v4v6_address ((char *) entdata->host_addr, + (char *) entdata->host_addr); + else if (af == AF_INET + && inet_pton (AF_INET6, addr, entdata->host_addr) > 0) + { + if (IN6_IS_ADDR_V4MAPPED (entdata->host_addr)) + memcpy (entdata->host_addr, entdata->host_addr + 12, INADDRSZ); + else if (IN6_IS_ADDR_LOOPBACK (entdata->host_addr)) + { + in_addr_t localhost = htonl (INADDR_LOOPBACK); + memcpy (entdata->host_addr, &localhost, sizeof (localhost)); + } + else + /* Illegal address: ignore line. */ + return 0; + } + else if (af == AF_UNSPEC + && inet_pton (AF_INET6, addr, entdata->host_addr) > 0) + af = AF_INET6; + else + /* Illegal address: ignore line. */ + return 0; + } + + /* We always return entries of the requested form. */ + result->h_addrtype = af; + result->h_length = af == AF_INET ? INADDRSZ : IN6ADDRSZ; + + /* Store a pointer to the address in the expected form. */ + entdata->h_addr_ptrs[0] = (char *) entdata->host_addr; + entdata->h_addr_ptrs[1] = NULL; + result->h_addr_list = entdata->h_addr_ptrs; + + STRING_FIELD (result->h_name, isspace, 1); + }) + +#define EXTRA_ARGS_VALUE \ + , (res_use_inet6 () ? AF_INET6 : AF_INET), \ + (res_use_inet6 () ? AI_V4MAPPED : 0) +#include "files-XXX.c" +#undef EXTRA_ARGS_VALUE + +/* We only need to consider IPv4 mapped addresses if the input to the + gethostbyaddr() function is an IPv6 address. */ +#define EXTRA_ARGS_VALUE \ + , af, (len == IN6ADDRSZ ? AI_V4MAPPED : 0) +DB_LOOKUP (hostbyaddr, ,,, + { + if (result->h_length == (int) len + && ! memcmp (addr, result->h_addr_list[0], len)) + break; + }, const void *addr, socklen_t len, int af) +#undef EXTRA_ARGS_VALUE + +enum nss_status +_nss_files_gethostbyname3_r (const char *name, int af, struct hostent *result, + char *buffer, size_t buflen, int *errnop, + int *herrnop, int32_t *ttlp, char **canonp) +{ + FILE *stream = NULL; + uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct hostent_data); + buffer += pad; + buflen = buflen > pad ? buflen - pad : 0; + + /* Open file. */ + enum nss_status status = internal_setent (&stream); + + if (status == NSS_STATUS_SUCCESS) + { + /* XXX Is using _res to determine whether we want to convert IPv4 + addresses to IPv6 addresses really the right thing to do? */ + int flags = (res_use_inet6 () ? AI_V4MAPPED : 0); + + while ((status = internal_getent (stream, result, buffer, buflen, errnop, + herrnop, af, flags)) + == NSS_STATUS_SUCCESS) + { + LOOKUP_NAME_CASE (h_name, h_aliases) + } + + if (status == NSS_STATUS_SUCCESS + && _res_hconf.flags & HCONF_FLAG_MULTI) + { + /* We have to get all host entries from the file. */ + size_t tmp_buflen = MIN (buflen, 4096); + char tmp_buffer_stack[tmp_buflen] + __attribute__ ((__aligned__ (__alignof__ (struct hostent_data)))); + char *tmp_buffer = tmp_buffer_stack; + struct hostent tmp_result_buf; + int naddrs = 1; + int naliases = 0; + char *bufferend; + bool tmp_buffer_malloced = false; + + while (result->h_aliases[naliases] != NULL) + ++naliases; + + bufferend = (char *) &result->h_aliases[naliases + 1]; + + again: + while ((status = internal_getent (stream, &tmp_result_buf, tmp_buffer, + tmp_buflen, errnop, herrnop, af, + flags)) + == NSS_STATUS_SUCCESS) + { + int matches = 1; + struct hostent *old_result = result; + result = &tmp_result_buf; + /* The following piece is a bit clumsy but we want to use the + `LOOKUP_NAME_CASE' value. The optimizer should do its + job. */ + do + { + LOOKUP_NAME_CASE (h_name, h_aliases) + result = old_result; + } + while ((matches = 0)); + + if (matches) + { + /* We could be very clever and try to recycle a few bytes + in the buffer instead of generating new arrays. But + we are not doing this here since it's more work than + it's worth. Simply let the user provide a bit bigger + buffer. */ + char **new_h_addr_list; + char **new_h_aliases; + int newaliases = 0; + size_t newstrlen = 0; + int cnt; + + /* Count the new aliases and the length of the strings. */ + while (tmp_result_buf.h_aliases[newaliases] != NULL) + { + char *cp = tmp_result_buf.h_aliases[newaliases]; + ++newaliases; + newstrlen += strlen (cp) + 1; + } + /* If the real name is different add it also to the + aliases. This means that there is a duplication + in the alias list but this is really the user's + problem. */ + if (strcmp (old_result->h_name, + tmp_result_buf.h_name) != 0) + { + ++newaliases; + newstrlen += strlen (tmp_result_buf.h_name) + 1; + } + + /* Make sure bufferend is aligned. */ + assert ((bufferend - (char *) 0) % sizeof (char *) == 0); + + /* Now we can check whether the buffer is large enough. + 16 is the maximal size of the IP address. */ + if (bufferend + 16 + (naddrs + 2) * sizeof (char *) + + roundup (newstrlen, sizeof (char *)) + + (naliases + newaliases + 1) * sizeof (char *) + >= buffer + buflen) + { + *errnop = ERANGE; + *herrnop = NETDB_INTERNAL; + status = NSS_STATUS_TRYAGAIN; + goto out; + } + + new_h_addr_list = + (char **) (bufferend + + roundup (newstrlen, sizeof (char *)) + + 16); + new_h_aliases = + (char **) ((char *) new_h_addr_list + + (naddrs + 2) * sizeof (char *)); + + /* Copy the old data in the new arrays. */ + for (cnt = 0; cnt < naddrs; ++cnt) + new_h_addr_list[cnt] = old_result->h_addr_list[cnt]; + + for (cnt = 0; cnt < naliases; ++cnt) + new_h_aliases[cnt] = old_result->h_aliases[cnt]; + + /* Store the new strings. */ + cnt = 0; + while (tmp_result_buf.h_aliases[cnt] != NULL) + { + new_h_aliases[naliases++] = bufferend; + bufferend = (__stpcpy (bufferend, + tmp_result_buf.h_aliases[cnt]) + + 1); + ++cnt; + } + + if (cnt < newaliases) + { + new_h_aliases[naliases++] = bufferend; + bufferend = __stpcpy (bufferend, + tmp_result_buf.h_name) + 1; + } + + /* Final NULL pointer. */ + new_h_aliases[naliases] = NULL; + + /* Round up the buffer end address. */ + bufferend += (sizeof (char *) + - ((bufferend - (char *) 0) + % sizeof (char *))) % sizeof (char *); + + /* Now the new address. */ + new_h_addr_list[naddrs++] = + memcpy (bufferend, tmp_result_buf.h_addr, + tmp_result_buf.h_length); + + /* Also here a final NULL pointer. */ + new_h_addr_list[naddrs] = NULL; + + /* Store the new array pointers. */ + old_result->h_aliases = new_h_aliases; + old_result->h_addr_list = new_h_addr_list; + + /* Compute the new buffer end. */ + bufferend = (char *) &new_h_aliases[naliases + 1]; + assert (bufferend <= buffer + buflen); + + result = old_result; + } + } + + if (status == NSS_STATUS_TRYAGAIN) + { + size_t newsize = 2 * tmp_buflen; + if (tmp_buffer_malloced) + { + char *newp = realloc (tmp_buffer, newsize); + if (newp != NULL) + { + assert ((((uintptr_t) newp) + & (__alignof__ (struct hostent_data) - 1)) + == 0); + tmp_buffer = newp; + tmp_buflen = newsize; + goto again; + } + } + else if (!__libc_use_alloca (buflen + newsize)) + { + tmp_buffer = malloc (newsize); + if (tmp_buffer != NULL) + { + assert ((((uintptr_t) tmp_buffer) + & (__alignof__ (struct hostent_data) - 1)) + == 0); + tmp_buffer_malloced = true; + tmp_buflen = newsize; + goto again; + } + } + else + { + tmp_buffer + = extend_alloca (tmp_buffer, tmp_buflen, + newsize + + __alignof__ (struct hostent_data)); + tmp_buffer = (char *) (((uintptr_t) tmp_buffer + + __alignof__ (struct hostent_data) + - 1) + & ~(__alignof__ (struct hostent_data) + - 1)); + goto again; + } + } + else + status = NSS_STATUS_SUCCESS; + out: + if (tmp_buffer_malloced) + free (tmp_buffer); + } + + internal_endent (&stream); + } + + if (canonp && status == NSS_STATUS_SUCCESS) + *canonp = result->h_name; + + return status; +} + +enum nss_status +_nss_files_gethostbyname_r (const char *name, struct hostent *result, + char *buffer, size_t buflen, int *errnop, + int *herrnop) +{ + int af = (res_use_inet6 () ? AF_INET6 : AF_INET); + + return _nss_files_gethostbyname3_r (name, af, result, buffer, buflen, + errnop, herrnop, NULL, NULL); +} + +enum nss_status +_nss_files_gethostbyname2_r (const char *name, int af, struct hostent *result, + char *buffer, size_t buflen, int *errnop, + int *herrnop) +{ + return _nss_files_gethostbyname3_r (name, af, result, buffer, buflen, + errnop, herrnop, NULL, NULL); +} + +enum nss_status +_nss_files_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat, + char *buffer, size_t buflen, int *errnop, + int *herrnop, int32_t *ttlp) +{ + FILE *stream = NULL; + + /* Open file. */ + enum nss_status status = internal_setent (&stream); + + if (status == NSS_STATUS_SUCCESS) + { + bool any = false; + bool got_canon = false; + while (1) + { + /* Align the buffer for the next record. */ + uintptr_t pad = (-(uintptr_t) buffer + % __alignof__ (struct hostent_data)); + buffer += pad; + buflen = buflen > pad ? buflen - pad : 0; + + struct hostent result; + status = internal_getent (stream, &result, buffer, buflen, errnop, + herrnop, AF_UNSPEC, 0); + if (status != NSS_STATUS_SUCCESS) + break; + + int naliases = 0; + if (__strcasecmp (name, result.h_name) != 0) + { + for (; result.h_aliases[naliases] != NULL; ++naliases) + if (! __strcasecmp (name, result.h_aliases[naliases])) + break; + if (result.h_aliases[naliases] == NULL) + continue; + + /* We know this alias exist. Count it. */ + ++naliases; + } + + /* Determine how much memory has been used so far. */ + // XXX It is not necessary to preserve the aliases array + while (result.h_aliases[naliases] != NULL) + ++naliases; + char *bufferend = (char *) &result.h_aliases[naliases + 1]; + assert (buflen >= bufferend - buffer); + buflen -= bufferend - buffer; + buffer = bufferend; + + /* We found something. */ + any = true; + + /* Create the record the caller expects. There is only one + address. */ + assert (result.h_addr_list[1] == NULL); + if (*pat == NULL) + { + uintptr_t pad = (-(uintptr_t) buffer + % __alignof__ (struct gaih_addrtuple)); + buffer += pad; + buflen = buflen > pad ? buflen - pad : 0; + + if (__builtin_expect (buflen < sizeof (struct gaih_addrtuple), + 0)) + { + *errnop = ERANGE; + *herrnop = NETDB_INTERNAL; + status = NSS_STATUS_TRYAGAIN; + break; + } + + *pat = (struct gaih_addrtuple *) buffer; + buffer += sizeof (struct gaih_addrtuple); + buflen -= sizeof (struct gaih_addrtuple); + } + + (*pat)->next = NULL; + (*pat)->name = got_canon ? NULL : result.h_name; + got_canon = true; + (*pat)->family = result.h_addrtype; + memcpy ((*pat)->addr, result.h_addr_list[0], result.h_length); + (*pat)->scopeid = 0; + + pat = &((*pat)->next); + + /* If we only look for the first matching entry we are done. */ + if ((_res_hconf.flags & HCONF_FLAG_MULTI) == 0) + break; + } + + /* If we have to look for multiple records and found one, this + is a success. */ + if (status == NSS_STATUS_NOTFOUND && any) + { + assert ((_res_hconf.flags & HCONF_FLAG_MULTI) != 0); + status = NSS_STATUS_SUCCESS; + } + + internal_endent (&stream); + } + else if (status == NSS_STATUS_TRYAGAIN) + { + *errnop = errno; + *herrnop = TRY_AGAIN; + } + else + { + *errnop = errno; + *herrnop = NO_DATA; + } + + return status; +} |