diff options
Diffstat (limited to 'ares_init.c')
-rw-r--r-- | ares_init.c | 550 |
1 files changed, 369 insertions, 181 deletions
diff --git a/ares_init.c b/ares_init.c index 863b3b0..823bef5 100644 --- a/ares_init.c +++ b/ares_init.c @@ -546,74 +546,331 @@ static int init_by_environment(ares_channel channel) #ifdef WIN32 /* - * Warning: returns a dynamically allocated buffer, the user MUST - * use free() if the function returns 1 + * get_REG_SZ() + * + * Given a 'hKey' handle to an open registry key and a 'leafKeyName' pointer + * to the name of the registry leaf key to be queried, fetch it's string + * value and return a pointer in *outptr to a newly allocated memory area + * holding it as a null-terminated string. + * + * Returns 0 and nullifies *outptr upon inability to return a string value. + * + * Returns 1 and sets *outptr when returning a dynamically allocated string. + * + * Supported on Windows NT 3.5 and newer. */ -static int get_res_nt(HKEY hKey, const char *subkey, char **obuf) +static int get_REG_SZ(HKEY hKey, const char *leafKeyName, char **outptr) { - /* Test for the size we need */ DWORD size = 0; - int result; + int res; + + *outptr = NULL; - result = RegQueryValueEx(hKey, subkey, 0, NULL, NULL, &size); - if ((result != ERROR_SUCCESS && result != ERROR_MORE_DATA) || !size) + /* Find out size of string stored in registry */ + res = RegQueryValueEx(hKey, leafKeyName, 0, NULL, NULL, &size); + if ((res != ERROR_SUCCESS && res != ERROR_MORE_DATA) || !size) return 0; - *obuf = malloc(size+1); - if (!*obuf) + + /* Allocate buffer of indicated size plus one given that string + might have been stored without null termination */ + *outptr = malloc(size+1); + if (!*outptr) return 0; - if (RegQueryValueEx(hKey, subkey, 0, NULL, - (LPBYTE)*obuf, &size) != ERROR_SUCCESS) + /* Get the value for real */ + res = RegQueryValueEx(hKey, leafKeyName, 0, NULL, + (unsigned char *)*outptr, &size); + if ((res != ERROR_SUCCESS) || (size == 1)) { - free(*obuf); + free(*outptr); + *outptr = NULL; return 0; } - if (size == 1) + + /* Null terminate buffer allways */ + *(*outptr + size) = '\0'; + + return 1; +} + +/* + * get_REG_SZ_9X() + * + * Functionally identical to get_REG_SZ() + * + * Supported on Windows 95, 98 and ME. + */ +static int get_REG_SZ_9X(HKEY hKey, const char *leafKeyName, char **outptr) +{ + DWORD dataType = 0; + DWORD size = 0; + int res; + + *outptr = NULL; + + /* Find out size of string stored in registry */ + res = RegQueryValueEx(hKey, leafKeyName, 0, &dataType, NULL, &size); + if ((res != ERROR_SUCCESS && res != ERROR_MORE_DATA) || !size) + return 0; + + /* Allocate buffer of indicated size plus one given that string + might have been stored without null termination */ + *outptr = malloc(size+1); + if (!*outptr) + return 0; + + /* Get the value for real */ + res = RegQueryValueEx(hKey, leafKeyName, 0, &dataType, + (unsigned char *)*outptr, &size); + if ((res != ERROR_SUCCESS) || (size == 1)) { - free(*obuf); + free(*outptr); + *outptr = NULL; return 0; } + + /* Null terminate buffer allways */ + *(*outptr + size) = '\0'; + return 1; } -static int get_res_interfaces_nt(HKEY hKey, const char *subkey, char **obuf) +/* + * get_enum_REG_SZ() + * + * Given a 'hKeyParent' handle to an open registry key and a 'leafKeyName' + * pointer to the name of the registry leaf key to be queried, parent key + * is enumerated searching in child keys for given leaf key name and its + * associated string value. When located, this returns a pointer in *outptr + * to a newly allocated memory area holding it as a null-terminated string. + * + * Returns 0 and nullifies *outptr upon inability to return a string value. + * + * Returns 1 and sets *outptr when returning a dynamically allocated string. + * + * Supported on Windows NT 3.5 and newer. + */ +static int get_enum_REG_SZ(HKEY hKeyParent, const char *leafKeyName, + char **outptr) { - char enumbuf[39]; /* GUIDs are 38 chars + 1 for NULL */ - DWORD enum_size = 39; - int idx = 0; - HKEY hVal; + char enumKeyName[256]; + DWORD enumKeyNameBuffSize; + DWORD enumKeyIdx = 0; + HKEY hKeyEnum; + int gotString; + int res; - while (RegEnumKeyEx(hKey, idx++, enumbuf, &enum_size, 0, - NULL, NULL, NULL) != ERROR_NO_MORE_ITEMS) - { - int rc; + *outptr = NULL; - enum_size = 39; - if (RegOpenKeyEx(hKey, enumbuf, 0, KEY_QUERY_VALUE, &hVal) != - ERROR_SUCCESS) + for(;;) + { + enumKeyNameBuffSize = sizeof(enumKeyName); + res = RegEnumKeyEx(hKeyParent, enumKeyIdx++, enumKeyName, + &enumKeyNameBuffSize, 0, NULL, NULL, NULL); + if (res != ERROR_SUCCESS) + break; + res = RegOpenKeyEx(hKeyParent, enumKeyName, 0, KEY_QUERY_VALUE, + &hKeyEnum); + if (res != ERROR_SUCCESS) continue; - rc = get_res_nt(hVal, subkey, obuf); - RegCloseKey(hVal); - if (rc) - return 1; - } - return 0; + gotString = get_REG_SZ(hKeyEnum, leafKeyName, outptr); + RegCloseKey(hKeyEnum); + if (gotString) + break; + } + + if (!*outptr) + return 0; + + return 1; } -/* get_iphlpapi_dns_classic() is supported on W98 and newer */ -static int get_iphlpapi_dns_classic(char *ret_buf, size_t ret_size) +/* + * get_DNS_Registry_9X() + * + * Functionally identical to get_DNS_Registry() + * + * Implementation supports Windows 95, 98 and ME. + */ +static int get_DNS_Registry_9X(char **outptr) +{ + HKEY hKey_VxD_MStcp; + int gotString; + int res; + + *outptr = NULL; + + res = RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_9X, 0, KEY_READ, + &hKey_VxD_MStcp); + if (res != ERROR_SUCCESS) + return 0; + + gotString = get_REG_SZ_9X(hKey_VxD_MStcp, NAMESERVER, outptr); + RegCloseKey(hKey_VxD_MStcp); + + if (!gotString || !*outptr) + return 0; + + return 1; +} + +/* + * get_DNS_Registry_NT() + * + * Functionally identical to get_DNS_Registry() + * + * Refs: Microsoft Knowledge Base articles KB120642 and KB314053. + * + * Implementation supports Windows NT 3.5 and newer. + */ +static int get_DNS_Registry_NT(char **outptr) +{ + HKEY hKey_Interfaces = NULL; + HKEY hKey_Tcpip_Parameters; + int gotString; + int res; + + *outptr = NULL; + + res = RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_NT_KEY, 0, KEY_READ, + &hKey_Tcpip_Parameters); + if (res != ERROR_SUCCESS) + return 0; + + /* + ** Global DNS settings override adapter specific parameters when both + ** are set. Additionally static DNS settings override DHCP-configured + ** parameters when both are set. + */ + + /* Global DNS static parameters */ + gotString = get_REG_SZ(hKey_Tcpip_Parameters, NAMESERVER, outptr); + if (gotString) + goto done; + + /* Global DNS DHCP-configured parameters */ + gotString = get_REG_SZ(hKey_Tcpip_Parameters, DHCPNAMESERVER, outptr); + if (gotString) + goto done; + + /* Try adapter specific parameters */ + res = RegOpenKeyEx(hKey_Tcpip_Parameters, "Interfaces", 0, + KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS, + &hKey_Interfaces); + if (res != ERROR_SUCCESS) + { + hKey_Interfaces = NULL; + goto done; + } + + /* Adapter specific DNS static parameters */ + gotString = get_enum_REG_SZ(hKey_Interfaces, NAMESERVER, outptr); + if (gotString) + goto done; + + /* Adapter specific DNS DHCP-configured parameters */ + gotString = get_enum_REG_SZ(hKey_Interfaces, DHCPNAMESERVER, outptr); + +done: + if (hKey_Interfaces) + RegCloseKey(hKey_Interfaces); + + RegCloseKey(hKey_Tcpip_Parameters); + + if (!gotString || !*outptr) + return 0; + + return 1; +} + +/* + * get_DNS_Registry() + * + * Locates DNS info in the registry. When located, this returns a pointer + * in *outptr to a newly allocated memory area holding a null-terminated + * string with a space or comma seperated list of DNS IP addresses. + * + * Returns 0 and nullifies *outptr upon inability to return DNSes string. + * + * Returns 1 and sets *outptr when returning a dynamically allocated string. + */ +static int get_DNS_Registry(char **outptr) +{ + win_platform platform; + int gotString = 0; + + *outptr = NULL; + + platform = ares__getplatform(); + + if (platform == WIN_NT) + gotString = get_DNS_Registry_NT(outptr); + else if (platform == WIN_9X) + gotString = get_DNS_Registry_9X(outptr); + + if (!gotString) + return 0; + + return 1; +} + +/* + * commajoin() + * + * RTF code. + */ +static void commajoin(char **dst, const char *src) +{ + char *tmp; + + if (*dst) + { + tmp = malloc(strlen(*dst) + strlen(src) + 2); + if (!tmp) + return; + sprintf(tmp, "%s,%s", *dst, src); + free(*dst); + *dst = tmp; + } + else + { + *dst = malloc(strlen(src) + 1); + if (!*dst) + return; + strcpy(*dst, src); + } +} + +/* + * get_DNS_NetworkParams() + * + * Locates DNS info using GetNetworkParams() function from the Internet + * Protocol Helper (IP Helper) API. When located, this returns a pointer + * in *outptr to a newly allocated memory area holding a null-terminated + * string with a space or comma seperated list of DNS IP addresses. + * + * Returns 0 and nullifies *outptr upon inability to return DNSes string. + * + * Returns 1 and sets *outptr when returning a dynamically allocated string. + * + * Implementation supports Windows 98 and newer. + * + * Note: Ancient PSDK required in order to build a W98 target. + */ +static int get_DNS_NetworkParams(char **outptr) { FIXED_INFO *fi, *newfi; struct ares_addr namesrvr; char *txtaddr; IP_ADDR_STRING *ipAddr; - size_t txtlen; - HRESULT res; + int res; DWORD size = sizeof (*fi); - char *endptr = ret_buf; - int count = 0; - *endptr = '\0'; + *outptr = NULL; + + /* Verify run-time availability of GetNetworkParams() */ + if (ares_fpGetNetworkParams == ZERO_NULL) + return 0; fi = malloc(size); if (!fi) @@ -621,16 +878,16 @@ static int get_iphlpapi_dns_classic(char *ret_buf, size_t ret_size) res = (*ares_fpGetNetworkParams) (fi, &size); if ((res != ERROR_BUFFER_OVERFLOW) && (res != ERROR_SUCCESS)) - goto quit; + goto done; newfi = realloc(fi, size); if (!newfi) - goto quit; + goto done; fi = newfi; res = (*ares_fpGetNetworkParams) (fi, &size); if (res != ERROR_SUCCESS) - goto quit; + goto done; for (ipAddr = &fi->DnsServerList; ipAddr; ipAddr = ipAddr->Next) { @@ -652,39 +909,47 @@ static int get_iphlpapi_dns_classic(char *ret_buf, size_t ret_size) else continue; - txtlen = strlen(txtaddr); - if (ret_size >= strlen(ret_buf) + txtlen + 2) - { - sprintf(endptr, "%s,", txtaddr); - endptr += txtlen + 1; - count++; - } + commajoin(outptr, txtaddr); + + if (!*outptr) + break; } -quit: +done: if (fi) free(fi); - if (endptr != ret_buf) - *(endptr - 1) = '\0'; + if (!*outptr) + return 0; - return count; + return 1; } +/* + * get_DNS_AdaptersAddresses() + * + * Locates DNS info using GetAdaptersAddresses() function from the Internet + * Protocol Helper (IP Helper) API. When located, this returns a pointer + * in *outptr to a newly allocated memory area holding a null-terminated + * string with a space or comma seperated list of DNS IP addresses. + * + * Returns 0 and nullifies *outptr upon inability to return DNSes string. + * + * Returns 1 and sets *outptr when returning a dynamically allocated string. + * + * Implementation supports Windows XP and newer. + */ #define IPAA_INITIAL_BUF_SZ 15 * 1024 #define IPAA_MAX_TRIES 3 - -static int get_iphlpapi_dns_info(char *ret_buf, size_t ret_size) +static int get_DNS_AdaptersAddresses(char **outptr) { IP_ADAPTER_DNS_SERVER_ADDRESS *ipaDNSAddr; IP_ADAPTER_ADDRESSES *ipaa, *newipaa, *ipaaEntry; - ULONG res; ULONG ReqBufsz = IPAA_INITIAL_BUF_SZ; ULONG Bufsz = IPAA_INITIAL_BUF_SZ; ULONG AddrFlags = 0; - char *endptr = ret_buf; int trying = IPAA_MAX_TRIES; - int count = 0; + int res; union { struct sockaddr *sa; @@ -693,13 +958,12 @@ static int get_iphlpapi_dns_info(char *ret_buf, size_t ret_size) } namesrvr; char txtaddr[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")]; - size_t txtlen; - /* Unless GetAdaptersAddresses is available, use GetNetworkParams */ - if (ares_fpGetAdaptersAddresses == ZERO_NULL) - return get_iphlpapi_dns_classic(ret_buf, ret_size); + *outptr = NULL; - *endptr = '\0'; + /* Verify run-time availability of GetAdaptersAddresses() */ + if (ares_fpGetAdaptersAddresses == ZERO_NULL) + return 0; ipaa = malloc(Bufsz); if (!ipaa) @@ -709,7 +973,7 @@ static int get_iphlpapi_dns_info(char *ret_buf, size_t ret_size) res = (*ares_fpGetAdaptersAddresses) (AF_UNSPEC, AddrFlags, NULL, ipaa, &ReqBufsz); if ((res != ERROR_BUFFER_OVERFLOW) && (res != ERROR_SUCCESS)) - goto quit; + goto done; while ((res == ERROR_BUFFER_OVERFLOW) && (--trying)) { @@ -717,7 +981,7 @@ static int get_iphlpapi_dns_info(char *ret_buf, size_t ret_size) { newipaa = realloc(ipaa, ReqBufsz); if (!newipaa) - goto quit; + goto done; Bufsz = ReqBufsz; ipaa = newipaa; } @@ -727,7 +991,7 @@ static int get_iphlpapi_dns_info(char *ret_buf, size_t ret_size) break; } if (res != ERROR_SUCCESS) - goto quit; + goto done; for (ipaaEntry = ipaa; ipaaEntry; ipaaEntry = ipaaEntry->Next) { @@ -758,24 +1022,49 @@ static int get_iphlpapi_dns_info(char *ret_buf, size_t ret_size) else continue; - txtlen = strlen(txtaddr); - if (ret_size >= strlen(ret_buf) + txtlen + 2) - { - sprintf(endptr, "%s,", txtaddr); - endptr += txtlen + 1; - count++; - } + commajoin(outptr, txtaddr); + + if (!*outptr) + goto done; } } -quit: +done: if (ipaa) free(ipaa); - if (endptr != ret_buf) - *(endptr - 1) = '\0'; + if (!*outptr) + return 0; + + return 1; +} + +/* + * get_DNS_Windows() + * + * Locates DNS info from Windows employing most suitable methods available at + * run-time no matter which Windows version it is. When located, this returns + * a pointer in *outptr to a newly allocated memory area holding a string with + * a space or comma seperated list of DNS IP addresses, null-terminated. + * + * Returns 0 and nullifies *outptr upon inability to return DNSes string. + * + * Returns 1 and sets *outptr when returning a dynamically allocated string. + * + * Implementation supports Windows 95 and newer. + */ +static int get_DNS_Windows(char **outptr) +{ + /* Try using IP helper API GetAdaptersAddresses() */ + if (get_DNS_AdaptersAddresses(outptr)) + return 1; - return count; + /* Try using IP helper API GetNetworkParams() */ + if (get_DNS_NetworkParams(outptr)) + return 1; + + /* Fall-back to registry information */ + return get_DNS_Registry(outptr); } #endif @@ -790,111 +1079,13 @@ static int init_by_resolv_conf(ares_channel channel) #ifdef WIN32 - /* - NameServer info via IPHLPAPI (IP helper API): - GetNetworkParams() should be the trusted source for this. - Available in Win-98/2000 and later. If that fail, fall-back to - registry information. - - NameServer Registry: - - On Windows 9X, the DNS server can be found in: -HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP\NameServer - - On Windows NT/2000/XP/2003: -HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\NameServer - or -HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\DhcpNameServer - or -HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\{AdapterID}\ -NameServer - or -HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\{AdapterID}\ -DhcpNameServer - */ - - HKEY mykey; - HKEY subkey; - DWORD data_type; - DWORD bytes; - DWORD result; - char buf[512]; - win_platform platform; - if (channel->nservers > -1) /* don't override ARES_OPT_SERVER */ return ARES_SUCCESS; - if (get_iphlpapi_dns_info(buf,sizeof(buf)) > 0) + if (get_DNS_Windows(&line)) { - status = config_nameserver(&servers, &nservers, buf); - if (status == ARES_SUCCESS) - goto okay; - } - - platform = ares__getplatform(); - - if (platform == WIN_NT) - { - if (RegOpenKeyEx( - HKEY_LOCAL_MACHINE, WIN_NS_NT_KEY, 0, - KEY_READ, &mykey - ) == ERROR_SUCCESS) - { - RegOpenKeyEx(mykey, "Interfaces", 0, - KEY_QUERY_VALUE|KEY_ENUMERATE_SUB_KEYS, &subkey); - if (get_res_nt(mykey, NAMESERVER, &line)) - { - status = config_nameserver(&servers, &nservers, line); - free(line); - } - else if (get_res_nt(mykey, DHCPNAMESERVER, &line)) - { - status = config_nameserver(&servers, &nservers, line); - free(line); - } - /* Try the interfaces */ - else if (get_res_interfaces_nt(subkey, NAMESERVER, &line)) - { - status = config_nameserver(&servers, &nservers, line); - free(line); - } - else if (get_res_interfaces_nt(subkey, DHCPNAMESERVER, &line)) - { - status = config_nameserver(&servers, &nservers, line); - free(line); - } - RegCloseKey(subkey); - RegCloseKey(mykey); - } - } - else if (platform == WIN_9X) - { - if (RegOpenKeyEx( - HKEY_LOCAL_MACHINE, WIN_NS_9X, 0, - KEY_READ, &mykey - ) == ERROR_SUCCESS) - { - if ((result = RegQueryValueEx( - mykey, NAMESERVER, NULL, &data_type, - NULL, &bytes - ) - ) == ERROR_SUCCESS || - result == ERROR_MORE_DATA) - { - if (bytes) - { - line = malloc(bytes+1); - if (RegQueryValueEx(mykey, NAMESERVER, NULL, &data_type, - (unsigned char *)line, &bytes) == - ERROR_SUCCESS) - { - status = config_nameserver(&servers, &nservers, line); - } - free(line); - } - } - } - RegCloseKey(mykey); + status = config_nameserver(&servers, &nservers, line); + free(line); } if (status == ARES_SUCCESS) @@ -1128,9 +1319,6 @@ DhcpNameServer } /* If we got any name server entries, fill them in. */ -#ifdef WIN32 -okay: -#endif if (servers) { channel->servers = servers; |