port-tunnel/src/main.c

#include "../kerep/src/base/base.h"
#include "../kerep/src/Network/network.h"

extern const char* help_message;

int errs(char* err_msg){
    throw(err_msg);
    return -1;
}

#define argIs(STR) cptr_equals(arg, STR)

#define argNext() argv[++argi < argc ? argi : errs(cptr_concat("option '",arg,"' must have a parameter"))]

typedef enum {
    TunnelProtocol_None,
    TunnelProtocol_TCP,
    TunnelProtocol_UDP
} TunnelProtocol;

typedef enum {
    InputMode_None,
    InputMode_Listen,
    InputMode_Connect
} InputMode;

typedef enum {
    OutputMode_None,
    OutputMode_Bind,
    OutputMode_Send
} OutputMode;

int main(int argc, const char* const* argv){
    kt_beginInit(false);
    kt_initKerepTypes();
    // kt_register(...);
    kt_endInit();

    TunnelProtocol tunnel_protocol = TunnelProtocol_None;
    InputMode input_mode = InputMode_None;
    OutputMode output_mode = OutputMode_None;
    knIPV4Endpoint input_end = knIPV4Endpoint_INVALID;
    knIPV4Endpoint output_end = knIPV4Endpoint_INVALID;
    const char* encryption_key = NULL;
    const char* decryption_key = NULL;

    if(argc < 2)
        throw("No arguments provided. Run the program with argument -h to see help message");

    for(int argi = 1; argi < argc; argi++){
        const char* arg = argv[argi];
        if(argIs("-h") || argIs("--help") || argIs("/?")){
            kprintf("%s"FGRY"\n", help_message);
            return 0;
        }
        else if(argIs("-p") || argIs("--protocol")){
            if(tunnel_protocol != TunnelProtocol_None)
                throw(cptr_concat("invalid option '",arg,"': tunnel protocol has been set already"));
            
            const char* protocol_str = argNext();
            char* protocol_str_lower = cptr_toLower(protocol_str);
            if(cptr_equals(protocol_str_lower, "tcp"))
                tunnel_protocol = TunnelProtocol_TCP;
            else if(cptr_equals(protocol_str_lower, "udp"))
                tunnel_protocol = TunnelProtocol_UDP;
            else throw(cptr_concat("invalid parameter '",protocol_str,"': unknown protocol"));
            free(protocol_str_lower);
        }
        else if(argIs("-l") || argIs("--listen")){
            if(input_mode != InputMode_None)
                throw(cptr_concat("invalid option '",arg,"': input mode has been set already"));
            
            input_mode = InputMode_Listen;
            const char* input_end_str = argNext();
            tryLast(knIPV4Endpoint_fromStr(input_end_str, &input_end), _m8612, ;);
        }
        else if(argIs("-c") || argIs("--connect")){
            if(input_mode != InputMode_None)
                throw(cptr_concat("invalid option '",arg,"': input mode has been set already"));
            
            input_mode = InputMode_Connect;
            const char* input_end_str = argNext();
            tryLast(knIPV4Endpoint_fromStr(input_end_str, &input_end), _m2612, ;);
        }
        else if(argIs("-s") || argIs("--send-to")){
            if(output_mode != OutputMode_None)
                throw(cptr_concat("invalid option '",arg,"': output mode has been set already"));
            if(input_mode != InputMode_Connect)
                throw(cptr_concat("invalid option '",arg,"': out endpoint setting is avaliable only in 'connect' program mode"));
            
            output_mode = OutputMode_Send;
            const char* output_end_str = argNext();
            tryLast(knIPV4Endpoint_fromStr(output_end_str, &output_end), _m8613, ;);
        }
        else if(argIs("-b") || argIs("--bind-to")){
            if(output_mode != OutputMode_None)
                throw(cptr_concat("invalid option '",arg,"': output mode has been set already"));
            if(input_mode != InputMode_Connect)
                throw(cptr_concat("invalid option '",arg,"': out endpoint setting is avaliable only in 'connect' program mode"));
            
            output_mode = OutputMode_Bind;
            const char* output_end_str = argNext();
            tryLast(knIPV4Endpoint_fromStr(output_end_str, &output_end), _m2613, ;);
        }
        else if(argIs("-e") || argIs("--encrypt")){
            if(encryption_key != NULL)
                throw(cptr_concat("invalid option '",arg,"': encryption key has been set already"));
            
            encryption_key = argNext();
            if(cptr_length(encryption_key) < 16)
                throw("too short encryption key (min length 16)");
            if(cptr_length(encryption_key) > 512)
                throw("too long encryption key (max length 512)");
        }
        else if(argIs("-d") || argIs("--decrypt")){
            if(decryption_key != NULL)
                throw(cptr_concat("invalid option '",arg,"': decryption key has been set already"));
            
            decryption_key = argNext();
            if(cptr_length(decryption_key) < 16)
                throw("too short decryption key (min length 16)");
            if(cptr_length(decryption_key) > 512)
                throw("too long decryption key (max length 512)");
        }
        else {
            throw(cptr_concat("invalid argument: ", arg));
        }
    }

    kprintf("tunnel_protocol: %i\n", tunnel_protocol);
    kprintf("input_mode: %i\n", input_mode);
    kprintf("output_mode: %i\n", output_mode);

    char* temps;
    if(!knIPV4Endpoint_isINVALID(input_end)){
        temps = knIPV4Endpoint_toString(&input_end);
        kprintf("input_end: %s\n", temps);
        free(temps);
    }
    else kprintf("input_end: INVALID\n");

    if(!knIPV4Endpoint_isINVALID(output_end)){
        temps = knIPV4Endpoint_toString(&output_end);
        kprintf("output_end: %s\n", temps);
        free(temps);
    }
    else kprintf("output_end: INVALID\n");

    kprintf("encryption_key: %s\n", encryption_key ? encryption_key : "NULL");
    kprintf("decryption_key: %s\n", decryption_key ? decryption_key : "NULL");

    return 0;
}