diff options
Diffstat (limited to 'src/openvpnserv/interactive.c')
| -rw-r--r-- | src/openvpnserv/interactive.c | 180 |
1 files changed, 173 insertions, 7 deletions
diff --git a/src/openvpnserv/interactive.c b/src/openvpnserv/interactive.c index ffaa171..ec54216 100644 --- a/src/openvpnserv/interactive.c +++ b/src/openvpnserv/interactive.c @@ -35,6 +35,12 @@ #include <sddl.h> #include <shellapi.h> +#ifdef HAVE_VERSIONHELPERS_H +#include <versionhelpers.h> +#else +#include "compat-versionhelpers.h" +#endif + #include "openvpn-msg.h" #include "validate.h" #include "block_dns.h" @@ -82,6 +88,8 @@ typedef enum { address, route, block_dns, + undo_dns4, + undo_dns6, _undo_type_max } undo_type_t; typedef list_item_t* undo_lists_t[_undo_type_max]; @@ -891,8 +899,7 @@ RegisterDNS (LPVOID unused) WCHAR sys_path[MAX_PATH]; DWORD timeout = RDNS_TIMEOUT * 1000; /* in milliseconds */ - /* default paths of net and ipconfig commands */ - WCHAR net[MAX_PATH] = L"C:\\Windows\\system32\\net.exe"; + /* default path of ipconfig command */ WCHAR ipcfg[MAX_PATH] = L"C:\\Windows\\system32\\ipconfig.exe"; struct @@ -901,8 +908,6 @@ RegisterDNS (LPVOID unused) WCHAR *cmdline; DWORD timeout; } cmds [] = { - { net, L"net stop dnscache", timeout }, - { net, L"net start dnscache", timeout }, { ipcfg, L"ipconfig /flushdns", timeout }, { ipcfg, L"ipconfig /registerdns", timeout }, }; @@ -912,9 +917,6 @@ RegisterDNS (LPVOID unused) if(GetSystemDirectory(sys_path, MAX_PATH)) { - _snwprintf (net, MAX_PATH, L"%s\\%s", sys_path, L"net.exe"); - net[MAX_PATH-1] = L'\0'; - _snwprintf (ipcfg, MAX_PATH, L"%s\\%s", sys_path, L"ipconfig.exe"); ipcfg[MAX_PATH-1] = L'\0'; } @@ -962,6 +964,156 @@ HandleRegisterDNSMessage (void) return err; } +/** + * Run the command: netsh interface $proto $action dns $if_name $addr [validate=no] + * @param action "delete" or "add" + * @param proto "ipv6" or "ip" + * @param if_name "name_of_interface" + * @param addr IPv4 (for proto = ip) or IPv6 address as a string + * + * If addr is null and action = "delete" all addresses are deleted. + */ +static DWORD +netsh_dns_cmd (const wchar_t *action, const wchar_t *proto, const wchar_t *if_name, const wchar_t *addr) +{ + DWORD err = 0; + int timeout = 30000; /* in msec */ + wchar_t argv0[MAX_PATH]; + + if (!addr) + { + if (wcscmp(action, L"delete") == 0) + addr = L"all"; + else /* nothing to do -- return success*/ + goto out; + } + + /* Path of netsh */ + int n = GetSystemDirectory (argv0, MAX_PATH); + if (n > 0 && n < MAX_PATH) /* got system directory */ + { + wcsncat(argv0, L"\\netsh.exe", MAX_PATH - n - 1); + } + else + { + wcsncpy(argv0, L"C:\\Windows\\system32\\netsh.exe", MAX_PATH); + } + + /* cmd template: + * netsh interface $proto $action dns $if_name $addr [validate=no] + */ + const wchar_t *fmt = L"netsh interface %s %s dns \"%s\" %s"; + + /* max cmdline length in wchars -- include room for worst case and some */ + int ncmdline = wcslen(fmt) + wcslen(if_name) + wcslen(addr) + 32 + 1; + wchar_t *cmdline = malloc(ncmdline*sizeof(wchar_t)); + if (!cmdline) + { + err = ERROR_OUTOFMEMORY; + goto out; + } + + openvpn_sntprintf (cmdline, ncmdline, fmt, proto, action, if_name, addr); + + if (IsWindows7OrGreater()) + { + wcsncat(cmdline, L" validate=no", ncmdline - wcslen(cmdline) - 1); + } + err = ExecCommand (argv0, cmdline, timeout); + +out: + free (cmdline); + return err; +} + +/* Delete all IPv4 or IPv6 dns servers for an interface */ +static DWORD +DeleteDNS(short family, wchar_t *if_name) +{ + wchar_t *proto = (family == AF_INET6) ? L"ipv6" : L"ip"; + return netsh_dns_cmd (L"delete", proto, if_name, NULL); +} + +/* Add an IPv4 or IPv6 dns server to an interface */ +static DWORD +AddDNS(short family, wchar_t *if_name, wchar_t *addr) +{ + wchar_t *proto = (family == AF_INET6) ? L"ipv6" : L"ip"; + return netsh_dns_cmd (L"add", proto, if_name, addr); +} + +static BOOL +CmpWString (LPVOID item, LPVOID str) +{ + return (wcscmp (item, str) == 0) ? TRUE : FALSE; +} + +static DWORD +HandleDNSConfigMessage (const dns_cfg_message_t *msg, undo_lists_t *lists) +{ + DWORD err = 0; + wchar_t addr[46]; /* large enough to hold string representation of an ipv4 / ipv6 address */ + undo_type_t undo_type = (msg->family == AF_INET6) ? undo_dns4 : undo_dns6; + int addr_len = msg->addr_len; + + /* sanity check */ + if (addr_len > _countof(msg->addr)) + addr_len = _countof(msg->addr); + + if (!msg->iface.name[0]) /* interface name is required */ + return ERROR_MESSAGE_DATA; + + wchar_t *wide_name = utf8to16(msg->iface.name); /* utf8 to wide-char */ + if (!wide_name) + return ERROR_OUTOFMEMORY; + + /* We delete all current addresses before adding any + * OR if the message type is del_dns_cfg + */ + if (addr_len > 0 || msg->header.type == msg_del_dns_cfg) + { + err = DeleteDNS(msg->family, wide_name); + if (err) + goto out; + free (RemoveListItem (&(*lists)[undo_type], CmpWString, wide_name)); + } + + if (msg->header.type == msg_del_dns_cfg) /* job done */ + goto out; + + for (int i = 0; i < addr_len; ++i) + { + if (msg->family == AF_INET6) + RtlIpv6AddressToStringW (&msg->addr[i].ipv6, addr); + else + RtlIpv4AddressToStringW (&msg->addr[i].ipv4, addr); + err = AddDNS(msg->family, wide_name, addr); + if (i == 0 && err) + goto out; + /* We do not check for duplicate addresses, so any error in adding + * additional addresses is ignored. + */ + } + + if (msg->addr_len > 0) + { + wchar_t *tmp_name = wcsdup(wide_name); + if (!tmp_name || AddListItem(&(*lists)[undo_type], tmp_name)) + { + free(tmp_name); + DeleteDNS(msg->family, wide_name); + err = ERROR_OUTOFMEMORY; + goto out; + } + } + + err = 0; + +out: + free(wide_name); + return err; +} + static VOID HandleMessage (HANDLE pipe, DWORD bytes, DWORD count, LPHANDLE events, undo_lists_t *lists) { @@ -972,6 +1124,7 @@ HandleMessage (HANDLE pipe, DWORD bytes, DWORD count, LPHANDLE events, undo_list route_message_t route; flush_neighbors_message_t flush_neighbors; block_dns_message_t block_dns; + dns_cfg_message_t dns; } msg; ack_message_t ack = { .header = { @@ -1017,6 +1170,11 @@ HandleMessage (HANDLE pipe, DWORD bytes, DWORD count, LPHANDLE events, undo_list ack.error_number = HandleRegisterDNSMessage (); break; + case msg_add_dns_cfg: + case msg_del_dns_cfg: + ack.error_number = HandleDNSConfigMessage (&msg.dns, lists); + break; + default: ack.error_number = ERROR_MESSAGE_TYPE; MsgToEventLog (MSG_FLAGS_ERROR, TEXT("Unknown message type %d"), msg.header.type); @@ -1048,6 +1206,14 @@ Undo (undo_lists_t *lists) DeleteRoute (item->data); break; + case undo_dns4: + DeleteDNS(AF_INET, item->data); + break; + + case undo_dns6: + DeleteDNS(AF_INET6, item->data); + break; + case block_dns: delete_block_dns_filters (item->data); item->data = NULL; |