9b056f5091
SDL_net is not very suitable for scrcpy. For example, SDLNet_TCP_Accept() is non-blocking, so we have to wrap it by calling many SDL_Net-specific functions to make it blocking. But above all, SDLNet_TCP_Open() is a server socket only when no IP is provided; otherwise, it's a client socket. Therefore, it is not possible to create a server socket bound to localhost, so it accepts connections from anywhere. This is a problem for scrcpy, because on start, the application listens for nearly 1 second until it accepts the first connection, supposedly from the device. If someone on the local network manages to connect to the server socket first, then they can stream arbitrary H.264 video. This may be troublesome, for example during a public presentation ;-) Provide our own simplified API (net.h) instead, implemented for the different platforms.
56 lines
1.4 KiB
C
56 lines
1.4 KiB
C
#include "net.h"
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#include "log.h"
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#ifdef __WINDOWS__
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typedef int socklen_t;
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#else
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# include <sys/types.h>
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# include <sys/socket.h>
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# include <netinet/in.h>
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# include <arpa/inet.h>
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# include <unistd.h>
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# define SOCKET_ERROR -1
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typedef struct sockaddr_in SOCKADDR_IN;
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typedef struct sockaddr SOCKADDR;
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typedef struct in_addr IN_ADDR;
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#endif
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socket_t net_listen(Uint32 addr, Uint16 port, int backlog) {
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socket_t sock = socket(AF_INET, SOCK_STREAM, 0);
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if (sock == INVALID_SOCKET) {
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LOGE("Cannot create socket");
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return INVALID_SOCKET;
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}
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SOCKADDR_IN sin;
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sin.sin_family = AF_INET;
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sin.sin_addr.s_addr = htonl(addr); // htonl() harmless on INADDR_ANY
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sin.sin_port = htons(port);
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if (bind(sock, (SOCKADDR *) &sin, sizeof(sin)) == SOCKET_ERROR) {
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LOGE("Cannot bind");
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return INVALID_SOCKET;
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}
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if (listen(sock, backlog) == SOCKET_ERROR) {
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LOGE("Cannot listen on port %" PRIu16, port);
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return INVALID_SOCKET;
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}
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return sock;
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}
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socket_t net_accept(socket_t server_socket) {
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SOCKADDR_IN csin;
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socklen_t sinsize = sizeof(csin);
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return accept(server_socket, (SOCKADDR *) &csin, &sinsize);
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}
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ssize_t net_recv(socket_t socket, void *buf, size_t len) {
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return recv(socket, buf, len, 0);
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}
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ssize_t net_send(socket_t socket, void *buf, size_t len) {
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return send(socket, buf, len, 0);
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}
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