libnx/nx/source/runtime/argv.c

#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <netinet/in.h>

#include "result.h"
#include "runtime/env.h"
#include "kernel/svc.h"

// System globals we define here
int __system_argc;
char** __system_argv;
struct in_addr __nxlink_host;

extern char* fake_heap_start;
extern char* fake_heap_end;

extern u8 __argdata__[];

static char* g_argv_empty = NULL;

void nxlinkSetup(void);

void argvSetup(void)
{
    Result rc=0;
    MemoryInfo meminfo;
    u32 pageinfo=0;

    u8 *argdata = __argdata__;
    u32 *arg32 = (u32*)argdata;
    u64 argdata_allocsize=0;
    u64 argdata_strsize=0;
    u32 argvptr_pos=0;
    u32 max_argv;
    u32 argi;
    u32 arglen=0;
    bool quote_flag=0;
    bool end_flag=0;
    char *args = NULL;
    char *argstart;
    char *argstorage;

    __system_argc = 0;
    __system_argv = &g_argv_empty;

    if (envIsNso()) {
        memset(&meminfo, 0, sizeof(meminfo));
        rc = svcQueryMemory(&meminfo, &pageinfo, (u64)argdata);

        // This memory is only mapped when arguments were passed.
        if (R_FAILED(rc) || meminfo.perm != 0x3)
            return;

        argdata_allocsize = (u64)arg32[0];
        argdata_strsize = (u64)arg32[1];
        args = (char*)&argdata[0x20];

        if (argdata_allocsize==0 || argdata_strsize==0) return;

        if ((u64)argdata < meminfo.addr) return;
        if (((u64)argdata - meminfo.addr) + argdata_allocsize > meminfo.size) return;

        argvptr_pos = 0x20 + argdata_strsize+1;
        if (argvptr_pos >= argdata_allocsize) return;
    }
    else if (envHasArgv()) {
        args = envGetArgv();
        argdata_allocsize = 0x9000;//Use the same size as NSO.
        argdata_strsize = strlen(args);
        argdata = (u8*)fake_heap_start;

        if (argdata_strsize==0) return;

        if (fake_heap_end - fake_heap_start < argdata_allocsize) return;

        fake_heap_start += argdata_allocsize;

        argvptr_pos = 0;

        memset(argdata, 0, argdata_allocsize);
    }

    argstorage = (char*)&argdata[argvptr_pos];

    argvptr_pos += (argdata_strsize+1 + 0x9) & ~0x7;
    if (argvptr_pos >= argdata_allocsize) return;

    max_argv = (argdata_allocsize - argvptr_pos) >> 3;
    if (max_argv < 2) return;

    __system_argv = (char**)&argdata[argvptr_pos];

    argstart = NULL;

    for(argi=0; argi<argdata_strsize; argi++) {
        if (argstart == NULL && isspace((unsigned char)args[argi])) continue;

        if (argstart == NULL) {
            if (args[argi] == '"') {
                argstart = &args[argi+1];
                quote_flag = 1;
            }
            else if(args[argi]!=0) {
                argstart = &args[argi];
                arglen++;
            }
        }
        else {
            end_flag = 0;

            if (quote_flag) {
                if (args[argi] == '"') end_flag = 1;
            }
            else if (isspace((unsigned char)args[argi])) {
                end_flag = 1;
            }

            if(end_flag==0 && args[argi]!=0) {
                arglen++;
            }

            if ((args[argi]==0 || end_flag) && arglen) {
                strncpy(argstorage, argstart, arglen);
                argstorage[arglen] = 0;
                __system_argv[__system_argc] = argstorage;
                __system_argc++;
                argstart = NULL;
                quote_flag = 0;
                argstorage+= arglen+1;
                arglen = 0;

                if (__system_argc >= max_argv) break;
            }
        }
    }

    if (arglen && __system_argc < max_argv) {
        strncpy(argstorage, argstart, arglen);
        argstorage[arglen] = 0;
        __system_argv[__system_argc] = argstorage;
        __system_argc++;
    }


    // Check for nxlink parameters
    nxlinkSetup();

    __system_argv[__system_argc] = NULL;


}