commit 5a4c6d53f50b264d60cf6453576ca2810c7890b7 Author: Siddhesh Poyarekar Date: Thu Nov 28 17:18:12 2013 +0530 Get canonical name in getaddrinfo from hosts file for AF_INET (fixes 16077) AF_INET lookup in hosts file uses _nss_files_gethostbyname2_r, which is not capable of returning a canonical name if it has found one. This change adds _nss_files_gethostbyname3_r, which wraps around _nss_files_gethostbyname2_r and then returns result.h_name as the canonical name. diff --git glibc-2.17-c758a686/nss/Versions glibc-2.17-c758a686/nss/Versions index d13d570..f8ababc 100644 --- glibc-2.17-c758a686/nss/Versions +++ glibc-2.17-c758a686/nss/Versions @@ -40,6 +40,7 @@ libnss_files { _nss_files_endhostent; _nss_files_gethostbyaddr_r; _nss_files_gethostbyname2_r; + _nss_files_gethostbyname3_r; _nss_files_gethostbyname4_r; _nss_files_gethostbyname_r; _nss_files_gethostent_r; diff --git glibc-2.17-c758a686/nss/nss_files/files-hosts.c glibc-2.17-c758a686/nss/nss_files/files-hosts.c index 6db2535..957c9aa 100644 --- glibc-2.17-c758a686/nss/nss_files/files-hosts.c +++ glibc-2.17-c758a686/nss/nss_files/files-hosts.c @@ -97,262 +97,12 @@ LINE_PARSER STRING_FIELD (result->h_name, isspace, 1); }) - - -#define HOST_DB_LOOKUP(name, keysize, keypattern, break_if_match, proto...) \ -enum nss_status \ -_nss_files_get##name##_r (proto, \ - struct STRUCTURE *result, char *buffer, \ - size_t buflen, int *errnop H_ERRNO_PROTO) \ -{ \ - uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct hostent_data); \ - buffer += pad; \ - buflen = buflen > pad ? buflen - pad : 0; \ - \ - __libc_lock_lock (lock); \ - \ - /* Reset file pointer to beginning or open file. */ \ - enum nss_status status = internal_setent (keep_stream); \ - \ - if (status == NSS_STATUS_SUCCESS) \ - { \ - /* Tell getent function that we have repositioned the file pointer. */ \ - last_use = getby; \ - \ - while ((status = internal_getent (result, buffer, buflen, errnop \ - H_ERRNO_ARG EXTRA_ARGS_VALUE)) \ - == NSS_STATUS_SUCCESS) \ - { break_if_match } \ - \ - 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 (&tmp_result_buf, tmp_buffer, \ - tmp_buflen, errnop H_ERRNO_ARG \ - EXTRA_ARGS_VALUE)) \ - == 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 \ - `break_if_match' value. The optimizer should do its \ - job. */ \ - do \ - { \ - break_if_match \ - 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); \ - } \ - \ - \ - if (! keep_stream) \ - internal_endent (); \ - } \ - \ - __libc_lock_unlock (lock); \ - \ - return status; \ -} - - #define EXTRA_ARGS_VALUE \ , ((_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET), \ ((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0) #include "files-XXX.c" -HOST_DB_LOOKUP (hostbyname, ,, - { - LOOKUP_NAME_CASE (h_name, h_aliases) - }, const char *name) #undef EXTRA_ARGS_VALUE - -/* XXX Is using _res to determine whether we want to convert IPv4 addresses - to IPv6 addresses really the right thing to do? */ -#define EXTRA_ARGS_VALUE \ - , af, ((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0) -HOST_DB_LOOKUP (hostbyname2, ,, - { - LOOKUP_NAME_CASE (h_name, h_aliases) - }, const char *name, int af) -#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 \ @@ -365,6 +115,263 @@ DB_LOOKUP (hostbyaddr, ,,, }, 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) +{ + uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct hostent_data); + buffer += pad; + buflen = buflen > pad ? buflen - pad : 0; + + __libc_lock_lock (lock); + + /* Reset file pointer to beginning or open file. */ + enum nss_status status = internal_setent (keep_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.options & RES_USE_INET6) ? AI_V4MAPPED : 0); + + /* Tell getent function that we have repositioned the file pointer. */ + last_use = getby; + + while ((status = internal_getent (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 (&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); + } + + if (! keep_stream) + internal_endent (); + } + + if (canonp && status == NSS_STATUS_SUCCESS) + *canonp = result->h_name; + + __libc_lock_unlock (lock); + + 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.options & 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,