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/* This Source Code Form is subject to the terms of the Mozilla Public↩
* License, v. 2.0. If a copy of the MPL was not distributed with this↩
↩
// To explain some of the oddities:↩
// This plugin avoids linking against a runtime that might not be present, thus↩
// it avoids standard library functions.↩
// NSIS requires GlobalAlloc/GlobalFree for its interfaces, and I use them for↩
// other allocations (vs e.g. HeapAlloc) for the sake of consistency.↩
↩
#include <Windows.h>↩
#include <Wininet.h>↩
↩
#define AGENT_NAME L"HttpPostFile plugin"↩
↩
PBYTE LoadFileData(LPWSTR fileName, DWORD& cbData);↩
bool HttpPost(LPURL_COMPONENTS pUrl, LPWSTR contentTypeHeader, PBYTE data,↩
DWORD cbData);↩
↩
// NSIS API↩
typedef struct _stack_t {↩
struct _stack_t* next;↩
WCHAR text[1];↩
} stack_t;↩
↩
// Unlink and return the topmost element of the stack, if any.↩
static stack_t* popstack(stack_t** stacktop) {↩
if (!stacktop || !*stacktop) return nullptr;↩
stack_t* element = *stacktop;↩
*stacktop = element->next;↩
element->next = nullptr;↩
return element;↩
}↩
↩
// Allocate a new stack element (with space for `stringsize`), copy the string,↩
// add to the top of the stack.↩
static void pushstring(LPCWSTR str, stack_t** stacktop,↩
unsigned int stringsize) {↩
stack_t* element;↩
if (!stacktop) return;↩
↩
// The allocation here has space for stringsize+1 WCHARs, because stack_t.text↩
// is 1 element long. This is consistent with the NSIS ExDLL example, though↩
// inconsistent with the comment that says the array "should be the length of↩
// g_stringsize when allocating". I'm sticking to consistency with↩
// the code, and erring towards having a larger buffer than necessary.↩
↩
element = (stack_t*)GlobalAlloc(↩
GPTR, (sizeof(stack_t) + stringsize * sizeof(*str)));↩
lstrcpynW(element->text, str, stringsize);↩
element->next = *stacktop;↩
*stacktop = element;↩
}↩
↩
BOOL APIENTRY DllMain(HINSTANCE instance, DWORD reason, LPVOID) {↩
// No initialization or cleanup is needed.↩
return TRUE;↩
}↩
↩
extern "C" {↩
↩
// HttpPostFile::Post <File> <Content-Type header with \r\n> <URL>↩
//↩
// e.g. HttpPostFile "C:\blah.json" "Content-Type: application/json$\r$\n"↩
//↩
// Leaves a result string on the stack, "success" if the POST was successful, an↩
// error message otherwise.↩
// The status code from the server is not checked, as long as we got some↩
// response the result will be "success". The response is read, but discarded.↩
void __declspec(dllexport)↩
Post(HWND hwndParent, int string_size, char* /* variables */,↩
stack_t** stacktop, void* /* extra_parameters */) {↩
static const URL_COMPONENTS kZeroComponents = {0};↩
const WCHAR* errorMsg = L"error";↩
↩
DWORD cbData = INVALID_FILE_SIZE;↩
PBYTE data = nullptr;↩
↩
// Copy a constant, because initializing an automatic variable with {0} ends↩
// up linking to memset, which isn't available.↩
URL_COMPONENTS components = kZeroComponents;↩
↩
// Get args, taking ownership of the strings from the stack, to avoid↩
// allocating and copying strings.↩
stack_t* postFileName = popstack(stacktop);↩
stack_t* contentTypeHeader = popstack(stacktop);↩
stack_t* url = popstack(stacktop);↩
↩
if (!postFileName || !contentTypeHeader || !url) {↩
errorMsg = L"error getting arguments";↩
goto finish;↩
}↩
↩
data = LoadFileData(postFileName->text, cbData);↩
if (!data || cbData == INVALID_FILE_SIZE) {↩
errorMsg = L"error reading file";↩
goto finish;↩
}↩
↩
{↩
// This length is used to allocate for the host name and path components,↩
// which should be no longer than the source URL.↩
int urlBufLen = lstrlenW(url->text) + 1;↩
↩
components.dwStructSize = sizeof(components);↩
components.dwHostNameLength = urlBufLen;↩
components.dwUrlPathLength = urlBufLen;↩
components.lpszHostName =↩
(LPWSTR)GlobalAlloc(GPTR, urlBufLen * sizeof(WCHAR));↩
components.lpszUrlPath =↩
(LPWSTR)GlobalAlloc(GPTR, urlBufLen * sizeof(WCHAR));↩
}↩
↩
errorMsg = L"error parsing URL";↩
if (components.lpszHostName && components.lpszUrlPath &&↩
InternetCrackUrl(url->text, 0, 0, &components) &&↩
(components.nScheme == INTERNET_SCHEME_HTTP ||↩
components.nScheme == INTERNET_SCHEME_HTTPS)) {↩
errorMsg = L"error sending HTTP request";↩
if (HttpPost(&components, contentTypeHeader->text, data, cbData)) {↩
// success!↩
errorMsg = nullptr;↩
}↩
}↩
↩
finish:↩
if (components.lpszUrlPath) {↩
GlobalFree(components.lpszUrlPath);↩
}↩
if (components.lpszHostName) {↩
GlobalFree(components.lpszHostName);↩
}↩
if (data) {↩
GlobalFree(data);↩
}↩
↩
// Free args taken from the NSIS stack↩
if (url) {↩
GlobalFree(url);↩
}↩
if (contentTypeHeader) {↩
GlobalFree(contentTypeHeader);↩
}↩
if (postFileName) {↩
GlobalFree(postFileName);↩
}↩
↩
if (errorMsg) {↩
pushstring(errorMsg, stacktop, string_size);↩
} else {↩
pushstring(L"success", stacktop, string_size);↩
}↩
}↩
}↩
↩
// Returns buffer with file contents on success, placing the size in cbData.↩
// Returns nullptr on failure.↩
// Caller must use GlobalFree() on the returned buffer if non-null.↩
PBYTE LoadFileData(LPWSTR fileName, DWORD& cbData) {↩
bool success = false;↩
↩
HANDLE hPostFile = INVALID_HANDLE_VALUE;↩
↩
PBYTE data = nullptr;↩
↩
DWORD bytesRead;↩
DWORD bytesReadTotal;↩
↩
hPostFile = CreateFile(fileName, GENERIC_READ, FILE_SHARE_READ, nullptr,↩
OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);↩
if (hPostFile == INVALID_HANDLE_VALUE) {↩
goto finish;↩
}↩
↩
cbData = GetFileSize(hPostFile, NULL);↩
if (cbData == INVALID_FILE_SIZE) {↩
goto finish;↩
}↩
↩
data = (PBYTE)GlobalAlloc(GPTR, cbData);↩
if (!data) {↩
goto finish;↩
}↩
↩
bytesReadTotal = 0;↩
do {↩
if (!ReadFile(hPostFile, data + bytesReadTotal, cbData - bytesReadTotal,↩
&bytesRead, nullptr /* overlapped */)) {↩
goto finish;↩
}↩
bytesReadTotal += bytesRead;↩
} while (bytesReadTotal < cbData && bytesRead > 0);↩
↩
if (bytesReadTotal == cbData) {↩
success = true;↩
}↩
↩
finish:↩
if (!success) {↩
if (data) {↩
GlobalFree(data);↩
data = nullptr;↩
}↩
cbData = INVALID_FILE_SIZE;↩
}↩
if (hPostFile != INVALID_HANDLE_VALUE) {↩
CloseHandle(hPostFile);↩
hPostFile = INVALID_HANDLE_VALUE;↩
}↩
↩
return data;↩
}↩
↩
// Returns true on success↩
bool HttpPost(LPURL_COMPONENTS pUrl, LPWSTR contentTypeHeader, PBYTE data,↩
DWORD cbData) {↩
bool success = false;↩
↩
HINTERNET hInternet = nullptr;↩
HINTERNET hConnect = nullptr;↩
HINTERNET hRequest = nullptr;↩
↩
hInternet = InternetOpen(AGENT_NAME, INTERNET_OPEN_TYPE_PRECONFIG,↩
nullptr, // proxy↩
nullptr, // proxy bypass↩
0 // flags↩
);↩
if (!hInternet) {↩
goto finish;↩
}↩
↩
hConnect = InternetConnect(hInternet, pUrl->lpszHostName, pUrl->nPort,↩
nullptr, // userName,↩
nullptr, // password↩
INTERNET_SERVICE_HTTP,↩
0, // flags↩
0 // context↩
);↩
if (!hConnect) {↩
goto finish;↩
}↩
↩
{↩
// NOTE: Some of these settings are perhaps unnecessary for a POST.↩
DWORD httpFlags = INTERNET_FLAG_NO_CACHE_WRITE | INTERNET_FLAG_NO_COOKIES |↩
INTERNET_FLAG_NO_UI | INTERNET_FLAG_RELOAD;↩
if (pUrl->nScheme == INTERNET_SCHEME_HTTPS) {↩
// NOTE: nsJSON sets flags to allow redirecting HTTPS to HTTP, or HTTP to↩
// HTTPS I left those out because it seemed undesirable for our use case.↩
httpFlags |= INTERNET_FLAG_SECURE;↩
}↩
hRequest = HttpOpenRequest(hConnect, L"POST", pUrl->lpszUrlPath,↩
nullptr, // version,↩
nullptr, // referrer↩
nullptr, // accept types↩
httpFlags,↩
0 // context↩
);↩
if (!hRequest) {↩
goto finish;↩
}↩
}↩
↩
if (contentTypeHeader) {↩
if (!HttpAddRequestHeaders(hRequest, contentTypeHeader,↩
-1L, // headers length (count string length)↩
HTTP_ADDREQ_FLAG_ADD)) {↩
goto finish;↩
}↩
}↩
↩
if (!HttpSendRequestW(hRequest,↩
nullptr, // additional headers↩
0, // headers length↩
data, cbData)) {↩
goto finish;↩
}↩
↩
BYTE readBuffer[1024];↩
DWORD bytesRead;↩
do {↩
if (!InternetReadFile(hRequest, readBuffer, sizeof(readBuffer),↩
&bytesRead)) {↩
goto finish;↩
}↩
// read data is thrown away↩
} while (bytesRead > 0);↩
↩
success = true;↩
↩
finish:↩
if (hRequest) {↩
InternetCloseHandle(hRequest);↩
}↩
if (hConnect) {↩
InternetCloseHandle(hConnect);↩
}↩
if (hInternet) {↩
InternetCloseHandle(hInternet);↩
}↩
↩
return success;↩
}