Hi,
On Mon, Oct 22, 2018 at 6:22 AM Lev Stipakov <lstipa...@gmail.com> wrote:
>
> From: Lev Stipakov <l...@openvpn.net>
>
> Every call to swprintf is followed by line which adds nul terminator. This
> patch
> introduces openvpn_swprintf() which guarantees nul termination for size > 0.
>
> Same approach as for snprintf / openvpn_snprintf.
>
> Signed-off-by: Lev Stipakov <l...@openvpn.net>
> ---
> v3:
> - add missing function declaration
> - fix indentation
>
> v2:
> - rebase on top of master
>
> src/openvpn/buffer.c | 17 +++++++++++++++++
> src/openvpn/buffer.h | 11 +++++++++++
> src/openvpn/tun.c | 3 +--
> src/openvpnserv/common.c | 15 +++++++++++++++
> src/openvpnserv/interactive.c | 26 ++++++++++----------------
> src/openvpnserv/service.h | 2 ++
> src/openvpnserv/validate.c | 3 +--
> 7 files changed, 57 insertions(+), 20 deletions(-)
>
> diff --git a/src/openvpn/buffer.c b/src/openvpn/buffer.c
> index 80fbb75..8ca189f 100644
> --- a/src/openvpn/buffer.c
> +++ b/src/openvpn/buffer.c
> @@ -37,6 +37,8 @@
>
> #include "memdbg.h"
>
> +#include <wchar.h>
> +
> size_t
> array_mult_safe(const size_t m1, const size_t m2, const size_t extra)
> {
> @@ -308,6 +310,21 @@ openvpn_snprintf(char *str, size_t size, const char
> *format, ...)
> return (len >= 0 && len < size);
> }
>
> +bool
> +openvpn_swprintf(wchar_t *const str, const size_t size, const wchar_t *const
> format, ...)
> +{
> + va_list arglist;
> + int len = -1;
> + if (size > 0)
> + {
> + va_start(arglist, format);
> + len = vswprintf(str, size, format, arglist);
> + va_end(arglist);
> + str[size - 1] = L'\0';
> + }
> + return (len >= 0 && len < size);
> +}
> +
> /*
> * write a string to the end of a buffer that was
> * truncated by buf_printf
> diff --git a/src/openvpn/buffer.h b/src/openvpn/buffer.h
> index aab249f..c5b78a0 100644
> --- a/src/openvpn/buffer.h
> +++ b/src/openvpn/buffer.h
> @@ -448,6 +448,17 @@ __attribute__ ((format(__printf__, 3, 4)))
> #endif
> ;
>
> +
> +/*
> + * Like swprintf but guarantees null termination for size > 0
> + */
> +bool
> +openvpn_swprintf(wchar_t *const str, const size_t size, const wchar_t *const
> format, ...);
> +/*
> + * Unlike in openvpn_snprintf, we cannot use format attributes since
> + * GCC doesn't support wprintf as archetype.
> + */
> +
> /*
> * remove/add trailing characters
> */
> diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
> index 948fd17..c091401 100644
> --- a/src/openvpn/tun.c
> +++ b/src/openvpn/tun.c
> @@ -4472,8 +4472,7 @@ get_adapter_index_method_1(const char *guid)
> DWORD index;
> ULONG aindex;
> wchar_t wbuf[256];
> - swprintf(wbuf, SIZE(wbuf), L"\\DEVICE\\TCPIP_%S", guid);
> - wbuf [SIZE(wbuf) - 1] = 0;
> + openvpn_swprintf(wbuf, SIZE(wbuf), L"\\DEVICE\\TCPIP_%S", guid);
> if (GetAdapterIndex(wbuf, &aindex) != NO_ERROR)
> {
> index = TUN_ADAPTER_INDEX_INVALID;
> diff --git a/src/openvpnserv/common.c b/src/openvpnserv/common.c
> index 33a8097..fd51776 100644
> --- a/src/openvpnserv/common.c
> +++ b/src/openvpnserv/common.c
> @@ -57,6 +57,21 @@ openvpn_sntprintf(LPTSTR str, size_t size, LPCTSTR format,
> ...)
> return res;
> }
>
> +BOOL
> +openvpn_swprintf(wchar_t *const str, const size_t size, const wchar_t *const
> format, ...)
> +{
> + va_list arglist;
> + int len = -1;
> + if (size > 0)
> + {
> + va_start(arglist, format);
> + len = vswprintf(str, size, format, arglist);
> + va_end(arglist);
> + str[size - 1] = L'\0';
> + }
> + return (len >= 0 && len < size);
> +}
> +
> static DWORD
> GetRegString(HKEY key, LPCTSTR value, LPTSTR data, DWORD size, LPCTSTR
> default_value)
> {
> diff --git a/src/openvpnserv/interactive.c b/src/openvpnserv/interactive.c
> index 4a571f5..2dc152c 100644
> --- a/src/openvpnserv/interactive.c
> +++ b/src/openvpnserv/interactive.c
> @@ -276,8 +276,7 @@ ReturnProcessId(HANDLE pipe, DWORD pid, DWORD count,
> LPHANDLE events)
> * Same format as error messages (3 line string) with error = 0 in
> * 0x%08x format, PID on line 2 and a description "Process ID" on line 3
> */
> - swprintf(buf, _countof(buf), L"0x%08x\n0x%08x\n%s", 0, pid, msg);
> - buf[_countof(buf) - 1] = '\0';
> + openvpn_swprintf(buf, _countof(buf), L"0x%08x\n0x%08x\n%s", 0, pid, msg);
>
> WritePipeAsync(pipe, buf, (DWORD)(wcslen(buf) * 2), count, events);
> }
> @@ -402,9 +401,8 @@ ValidateOptions(HANDLE pipe, const WCHAR *workdir, const
> WCHAR *options)
>
> if (!CheckOption(workdir, 2, argv_tmp, &settings))
> {
> - swprintf(buf, _countof(buf), msg1, argv[0], workdir,
> - settings.ovpn_admin_group);
> - buf[_countof(buf) - 1] = L'\0';
> + openvpn_swprintf(buf, _countof(buf), msg1, argv[0], workdir,
> + settings.ovpn_admin_group);
> ReturnError(pipe, ERROR_STARTUP_DATA, buf, 1, &exit_event);
> }
> goto out;
> @@ -421,16 +419,14 @@ ValidateOptions(HANDLE pipe, const WCHAR *workdir,
> const WCHAR *options)
> {
> if (wcscmp(L"--config", argv[i]) == 0 && argc-i > 1)
> {
> - swprintf(buf, _countof(buf), msg1, argv[i+1], workdir,
> - settings.ovpn_admin_group);
> - buf[_countof(buf) - 1] = L'\0';
> + openvpn_swprintf(buf, _countof(buf), msg1, argv[i+1],
> workdir,
> + settings.ovpn_admin_group);
> ReturnError(pipe, ERROR_STARTUP_DATA, buf, 1, &exit_event);
> }
> else
> {
> - swprintf(buf, _countof(buf), msg2, argv[i],
> - settings.ovpn_admin_group);
> - buf[_countof(buf) - 1] = L'\0';
> + openvpn_swprintf(buf, _countof(buf), msg2, argv[i],
> + settings.ovpn_admin_group);
> ReturnError(pipe, ERROR_STARTUP_DATA, buf, 1, &exit_event);
> }
> goto out;
> @@ -950,8 +946,7 @@ RegisterDNS(LPVOID unused)
>
> HANDLE wait_handles[2] = {rdns_semaphore, exit_event};
>
> - swprintf(ipcfg, _countof(ipcfg), L"%s\\%s", get_win_sys_path(),
> L"ipconfig.exe");
> - ipcfg[_countof(ipcfg) - 1] = L'\0';
> + openvpn_swprintf(ipcfg, MAX_PATH, L"%s\\%s", get_win_sys_path(),
> L"ipconfig.exe");
>
> if (WaitForMultipleObjects(2, wait_handles, FALSE, timeout) ==
> WAIT_OBJECT_0)
> {
> @@ -1628,9 +1623,8 @@ RunOpenvpn(LPVOID p)
> else if (exit_code != 0)
> {
> WCHAR buf[256];
> - swprintf(buf, _countof(buf),
> - L"OpenVPN exited with error: exit code = %lu", exit_code);
> - buf[_countof(buf) - 1] = L'\0';
> + openvpn_swprintf(buf, _countof(buf),
> + L"OpenVPN exited with error: exit code = %lu",
> exit_code);
> ReturnError(pipe, ERROR_OPENVPN_STARTUP, buf, 1, &exit_event);
> }
> Undo(&undo_lists);
> diff --git a/src/openvpnserv/service.h b/src/openvpnserv/service.h
> index d7b7b3f..cb7020f 100644
> --- a/src/openvpnserv/service.h
> +++ b/src/openvpnserv/service.h
> @@ -86,6 +86,8 @@ BOOL openvpn_vsntprintf(LPTSTR str, size_t size, LPCTSTR
> format, va_list arglist
>
> BOOL openvpn_sntprintf(LPTSTR str, size_t size, LPCTSTR format, ...);
>
> +BOOL openvpn_swprintf(wchar_t *const str, const size_t size, const wchar_t
> *const format, ...);
> +
> DWORD GetOpenvpnSettings(settings_t *s);
>
> BOOL ReportStatusToSCMgr(SERVICE_STATUS_HANDLE service, SERVICE_STATUS
> *status);
> diff --git a/src/openvpnserv/validate.c b/src/openvpnserv/validate.c
> index c576ac1..5506e90 100644
> --- a/src/openvpnserv/validate.c
> +++ b/src/openvpnserv/validate.c
> @@ -68,8 +68,7 @@ CheckConfigPath(const WCHAR *workdir, const WCHAR *fname,
> const settings_t *s)
> /* convert fname to full path */
> if (PathIsRelativeW(fname) )
> {
> - swprintf(tmp, _countof(tmp), L"%s\\%s", workdir, fname);
> - tmp[_countof(tmp)-1] = L'\0';
> + openvpn_swprintf(tmp, _countof(tmp), L"%s\\%s", workdir, fname);
> config_file = tmp;
> }
> else
Acked-by: Selva Nair <selva.n...@gmail.com>
_______________________________________________
Openvpn-devel mailing list
Openvpn-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/openvpn-devel
