GitCaddy/Desktop Trampoline
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Extract (and abstract) socket stuff to its own module

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This commit is contained in:
Sergio Padrino
2021-02-01 11:20:05 +01:00
parent 1eb5fa54e2
commit b5b7806171
4 changed files with 143 additions and 74 deletions
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16
binding.gyp
View File

@@ -4,7 +4,21 @@
'target_name': 'desktop-trampoline',
'type': 'executable',
'sources': [
'src/desktop-trampoline.c'
'src/desktop-trampoline.c',
'src/socket.c'
],
'include_dirs': [
'include'
],
"xcode_settings": {
'OTHER_CFLAGS': [
'-Wall',
'-Werror'
],
},
'cflags!': [
'-Wall',
'-Werror',
],
'conditions': [
['OS=="win"', {

40
include/socket.h Normal file
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@@ -0,0 +1,40 @@
#ifdef WINDOWS
#include <winsock.h>
#else
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#endif
// There are some types missing to make everything Just Work™ in all platforms
#ifdef WINDOWS
#define ssize_t long
#else
#define SOCKET int
#define INVALID_SOCKET -1
#endif
/** Initializes anything required before working with sockets. */
int initializeNetwork(void);
/** Frees resources initialized by `initializeNetwork`. */
void terminateNetwork(void);
/** Creates a TCP socket and returns its handler. */
SOCKET openSocket(void);
/** Closes an open socket. */
void closeSocket(SOCKET socket);
/** Connects to a given port using a socket. */
int connectSocket(SOCKET socket, unsigned short port);
/** Writes data into a socket. */
int writeSocket(SOCKET socket, const void *buffer, size_t length);
/** Reads data from a socket. */
int readSocket(SOCKET socket, void *buffer, size_t length);
/** Prints socket-related errors to stderr. */
void printSocketError(char *fmt, ...);

89
src/desktop-trampoline.c
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@@ -1,59 +1,15 @@
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <errno.h>
#ifdef WINDOWS
#include <winsock.h>
#define ssize_t long
#else
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#define SOCKET int
#define INVALID_SOCKET -1
#endif
#include "socket.h"
#define BUFFER_LENGTH 4096
int safeSend(SOCKET socket, const void *buffer, size_t length, int flags) {
return (send(socket, buffer, length, flags) < (ssize_t)length ? -1 : 0);
}
void closeSocket(SOCKET socket) {
#ifdef WINDOWS
closesocket(socket);
#else
close(socket);
#endif
}
void printSocketError(char *fmt, ...)
{
char formatted_string[4096];
va_list argptr;
va_start(argptr, fmt);
vsprintf(formatted_string, fmt, argptr);
va_end(argptr);
#ifdef WINDOWS
fprintf(stderr, "%s: %ld\n", formatted_string, WSAGetLastError());
#else
fprintf(stderr, "%s (%d): %s\n", formatted_string, errno, strerror(errno));
#endif
}
#define SEND_STRING_OR_EXIT(socket, dataName, dataString) \
if (safeSend(socket, dataString, strlen(dataString) + 1, 0) != 0) { \
#define WRITE_STRING_OR_EXIT(dataName, dataString) \
if (writeSocket(socket, dataString, strlen(dataString) + 1) != 0) { \
printSocketError("ERROR: Couldn't send " dataName); \
return 1; \
}
@@ -75,21 +31,16 @@ int runTrampolineClient(SOCKET *outSocket, int argc, char **argv, char **envp) {
unsigned short desktopPort = atoi(desktopPortString);
SOCKET s = socket(AF_INET, SOCK_STREAM, 0);
SOCKET socket = openSocket();
if (s == INVALID_SOCKET) {
if (socket == INVALID_SOCKET) {
printSocketError("ERROR: Couldn't create TCP socket");
return 1;
}
*outSocket = s;
*outSocket = socket;
struct sockaddr_in remote = {0};
remote.sin_addr.s_addr = inet_addr("127.0.0.1");
remote.sin_family = AF_INET;
remote.sin_port = htons(desktopPort);
if (connect(s, (struct sockaddr *)&remote, sizeof(struct sockaddr_in)) != 0) {
if (connectSocket(socket, desktopPort) != 0) {
printSocketError("ERROR: Couldn't connect to 127.0.0.1:%d", desktopPort);
return 1;
}
@@ -97,11 +48,11 @@ int runTrampolineClient(SOCKET *outSocket, int argc, char **argv, char **envp) {
// Send the number of arguments
char argcString[33];
snprintf(argcString, 33, "%d", argc);
SEND_STRING_OR_EXIT(s, "number of arguments", argcString);
WRITE_STRING_OR_EXIT("number of arguments", argcString);
// Send each argument separated by \0
for (int idx = 0; idx < argc; idx++) {
SEND_STRING_OR_EXIT(s, "argument", argv[idx]);
WRITE_STRING_OR_EXIT("argument", argv[idx]);
}
// Get the number of environment variables
@@ -113,12 +64,12 @@ int runTrampolineClient(SOCKET *outSocket, int argc, char **argv, char **envp) {
// Send the number of environment variables
char envcString[33];
snprintf(envcString, 33, "%d", envc);
SEND_STRING_OR_EXIT(s, "number of environment variables", envcString);
WRITE_STRING_OR_EXIT("number of environment variables", envcString);
// Send the environment variables
for (char **env = envp; *env != 0; env++) {
char *thisEnv = *env;
SEND_STRING_OR_EXIT(s, "environment variable", thisEnv);
WRITE_STRING_OR_EXIT("environment variable", thisEnv);
}
// TODO: send stdin stuff?
@@ -129,7 +80,7 @@ int runTrampolineClient(SOCKET *outSocket, int argc, char **argv, char **envp) {
// Read output from server
do {
bytesRead = recv(s, buffer + totalBytesRead, BUFFER_LENGTH - totalBytesRead, 0);
bytesRead = readSocket(socket, buffer + totalBytesRead, BUFFER_LENGTH - totalBytesRead);
if (bytesRead == -1) {
printSocketError("ERROR: Error reading from socket");
@@ -148,15 +99,9 @@ int runTrampolineClient(SOCKET *outSocket, int argc, char **argv, char **envp) {
}
int main(int argc, char **argv, char **envp) {
#ifdef WINDOWS
// Initialize Winsock
WSADATA wsaData;
int iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
if (iResult != NO_ERROR) {
fprintf(stderr, "ERROR: WSAStartup failed: %d\n", iResult);
if (initializeNetwork() != 0) {
return 1;
}
#endif
SOCKET socket = INVALID_SOCKET;
int result = runTrampolineClient(&socket, argc, argv, envp);
@@ -166,9 +111,7 @@ int main(int argc, char **argv, char **envp) {
closeSocket(socket);
}
#ifdef WINDOWS
WSACleanup();
#endif
terminateNetwork();
return result;
}

72
src/socket.c Normal file
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@@ -0,0 +1,72 @@
#include "socket.h"
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int initializeNetwork(void) {
#ifdef WINDOWS
// Initialize Winsock
WSADATA wsaData;
int result = WSAStartup(MAKEWORD(2,2), &wsaData);
if (result != NO_ERROR) {
fprintf(stderr, "ERROR: WSAStartup failed: %d\n", result);
return 1;
}
#endif
return 0;
}
void terminateNetwork(void) {
#ifdef WINDOWS
WSACleanup();
#endif
}
SOCKET openSocket(void) {
return socket(AF_INET, SOCK_STREAM, 0);
}
void closeSocket(SOCKET socket) {
#ifdef WINDOWS
closesocket(socket);
#else
close(socket);
#endif
}
int connectSocket(SOCKET socket, unsigned short port) {
struct sockaddr_in remote = {0};
remote.sin_addr.s_addr = inet_addr("127.0.0.1");
remote.sin_family = AF_INET;
remote.sin_port = htons(port);
return connect(socket, (struct sockaddr *)&remote, sizeof(struct sockaddr_in));
}
int writeSocket(SOCKET socket, const void *buffer, size_t length) {
return (send(socket, buffer, length, 0) < (ssize_t)length ? -1 : 0);
}
int readSocket(SOCKET socket, void *buffer, size_t length) {
return recv(socket, buffer, length, 0);
}
void printSocketError(char *fmt, ...)
{
char formatted_string[4096];
va_list argptr;
va_start(argptr, fmt);
vsprintf(formatted_string, fmt, argptr);
va_end(argptr);
#ifdef WINDOWS
fprintf(stderr, "%s: %ld\n", formatted_string, WSAGetLastError());
#else
fprintf(stderr, "%s (%d): %s\n", formatted_string, errno, strerror(errno));
#endif
}