pack your shit, kids, we're moving

1 files changed, 144 insertions, 1 deletions

diff --git a/src/libui_sdl/LAN.cpp b/src/libui_sdl/LAN.cpp
index 1569f80..985e973 100644
--- a/src/libui_sdl/LAN.cpp
+++ b/src/libui_sdl/LAN.cpp
@@ -16,12 +16,155 @@
     with melonDS. If not, see http://www.gnu.org/licenses/.
 */
 
+// LAN interface. Currently powered by libpcap, may change.
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <SDL2/SDL.h>
+#include <pcap/pcap.h>
 #include "LAN.h"
 
 
+// welp
+#ifndef PCAP_OPENFLAG_PROMISCUOUS
+#define PCAP_OPENFLAG_PROMISCUOUS 1
+#endif
+
+
+#define DECL_PCAP_FUNC(ret, name, args, args2) \
+    typedef ret (*type_##name) args; \
+    type_##name ptr_##name = NULL; \
+    ret name args { return ptr_##name args2; }
+
+DECL_PCAP_FUNC(int, pcap_findalldevs, (pcap_if_t** alldevs, char* errbuf), (alldevs,errbuf))
+DECL_PCAP_FUNC(void, pcap_freealldevs, (pcap_if_t* alldevs), (alldevs))
+DECL_PCAP_FUNC(pcap_t*, pcap_open_live, (const char* src, int snaplen, int flags, int readtimeout, char* errbuf), (src,snaplen,flags,readtimeout,errbuf))
+DECL_PCAP_FUNC(void, pcap_close, (pcap_t* dev), (dev))
+DECL_PCAP_FUNC(int, pcap_setnonblock, (pcap_t* dev, int nonblock, char* errbuf), (dev,nonblock,errbuf))
+DECL_PCAP_FUNC(int, pcap_sendpacket, (pcap_t* dev, const u_char* data, int len), (dev,data,len))
+DECL_PCAP_FUNC(int, pcap_dispatch, (pcap_t* dev, int num, pcap_handler callback, u_char* data), (dev,num,callback,data))
+
+
 namespace LAN
 {
 
-//
+const char* PCapLibNames[] =
+{
+#ifdef __WIN32__
+    // TODO: name for npcap in non-WinPCap mode
+    "wpcap.dll",
+#else
+    // Linux lib names
+    "libpcap.so.1",
+    "libpcap.so",
+#endif
+    NULL
+};
+
+void* PCapLib = NULL;
+pcap_t* PCapAdapter = NULL;
+
+u8 PCapPacketBuffer[2048];
+int PCapPacketLen;
+int PCapRXNum;
+
+
+#define LOAD_PCAP_FUNC(sym) \
+    ptr_##sym = (type_##sym)SDL_LoadFunction(lib, #sym); \
+    if (!ptr_##sym) return false;
+
+bool TryLoadPCap(void* lib)
+{
+    LOAD_PCAP_FUNC(pcap_findalldevs)
+    LOAD_PCAP_FUNC(pcap_freealldevs)
+    LOAD_PCAP_FUNC(pcap_open_live)
+    LOAD_PCAP_FUNC(pcap_close)
+    LOAD_PCAP_FUNC(pcap_setnonblock)
+    LOAD_PCAP_FUNC(pcap_sendpacket)
+    LOAD_PCAP_FUNC(pcap_dispatch)
+
+    return true;
+}
+
+bool Init()
+{
+    PCapLib = NULL;
+    PCapAdapter = NULL;
+    PCapPacketLen = 0;
+    PCapRXNum = 0;
+
+    for (int i = 0; PCapLibNames[i]; i++)
+    {
+        void* lib = SDL_LoadObject(PCapLibNames[i]);
+        if (!lib) continue;
+
+        if (!TryLoadPCap(lib))
+        {
+            SDL_UnloadObject(lib);
+            continue;
+        }
+
+        printf("PCap: lib %s, init successful\n", PCapLibNames[i]);
+        PCapLib = lib;
+        break;
+    }
+
+    if (PCapLib == NULL)
+    {
+        printf("PCap: init failed\n");
+        return false;
+    }
+
+    char errbuf[PCAP_ERRBUF_SIZE];
+    int ret;
+
+    pcap_if_t* alldevs;
+    ret = pcap_findalldevs(&alldevs, errbuf);
+    if (ret < 0 || alldevs == NULL)
+    {
+        printf("PCap: no devices available\n");
+        return false;
+    }
+/*while (alldevs){
+    printf("picking dev %08X %s | %s\n", alldevs->flags, alldevs->name, alldevs->description);
+    alldevs = alldevs->next;}*/
+    // temp hack
+    // TODO: ADAPTER SELECTOR!!
+    pcap_if_t* dev = alldevs->next;
+
+    PCapAdapter = pcap_open_live(dev->name, 2048, PCAP_OPENFLAG_PROMISCUOUS, 1, errbuf);
+    if (!PCapAdapter)
+    {
+        printf("PCap: failed to open adapter\n");
+        return false;
+    }
+
+    pcap_freealldevs(alldevs);
+
+    if (pcap_setnonblock(PCapAdapter, 1, errbuf) < 0)
+    {
+        printf("PCap: failed to set nonblocking mode\n");
+        pcap_close(PCapAdapter); PCapAdapter = NULL;
+        return false;
+    }
+
+    return true;
+}
+
+void DeInit()
+{
+    if (PCapLib)
+    {
+        if (PCapAdapter)
+        {
+            pcap_close(PCapAdapter);
+            PCapAdapter = NULL;
+        }
+
+        SDL_UnloadObject(PCapLib);
+        PCapLib = NULL;
+    }
+}
 
 }