#include <my_sock.h>
#include <sys/stat.h>

#define PORT 6969
#define BUFSIZE 8192

int main(int argc, char **argv)
{
    int     sock = 0, fd = 0, sendret = 0, nread = 0;
    char    buf[BUFSIZE];
    struct  sockaddr_in servaddr;
    struct stat     statbuf;

    if (argc != 3){
        printf("Usage: %s <server ip> <file>\n", argv[0]);
        return 1;
    }

    //initialize the socket -- returns < 0 on error
    if ( (sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
        err_quit("socket");

    //open the file
    if( (fd = open(argv[2], O_RDONLY)) < 0)
        err_quit("open");

    //setup the sock_addrin structure
    memset(&servaddr, 0, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_port   = htons(PORT);
    servaddr.sin_addr.s_addr = inet_addr(argv[1]);

    //connect to the server, returns < 0 on error
    if (connect(sock, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0)
        err_quit("connect");

    //send the file
    while( (nread = read(fd, buf, BUFSIZE)) > 0)
        if(write(sock, buf, nread) < 0)
            err_quit("write");

    close(fd);
    close(sock);

    return 0;
}

#include <mlib/my_sock.h>
#include <errno.h>
    
#define PORT 6969
#define BUFSIZE 8192
#define PERM (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)
#define MAXTHREADS 25

void * f00(void *data)
{   
    char    buf[BUFSIZE];
    int asock = (int) data, nread = 0, fd = 0;
    
    //open the file
    if( (fd = open("tmp", O_CREAT | O_TRUNC | O_WRONLY, PERM)) < 0)
        err_quit("open");
    
    //read from socket, write to file
    while( (nread = read(asock, buf, BUFSIZE)) > 0) 
        if(write(fd, buf, nread) != nread)
            err_quit("write");
        
    close(fd);
    return;
};          

int main(int argc, char **argv)
{       
    u_int   rbufsz = 64000;
    int     on = 1, fd = 0, lsock = 0, asock = 0, nread = 0, nthreads = 0, x = 0;
    char    buf[BUFSIZE];
    struct  sockaddr_in sa, csa;
    struct in_addr  *inptr = NULL;
    socklen_t len = sizeof(sa);
    pthread_t   threadid[MAXTHREADS];
    
    //initialize the socket -- returns < 0 on error
    if ( (lsock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
        perr_quit("socket");
    
    if(setsockopt(lsock, SOL_SOCKET, SO_RCVBUF, &rbufsz, sizeof(rbufsz)) != 0)
        perr_quit("setsockopt");
    
    if(setsockopt(lsock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
        perr_quit("setsockopt");

    //setup the sock_addrin structure
    memset(&sa, 0, sizeof(sa));
    memset(&csa, 0, sizeof(csa));
    sa.sin_family = AF_INET;
    sa.sin_port   = htons(PORT);    
    sa.sin_addr.s_addr = htonl(INADDR_ANY);
    
    //bind socket 
    if( (bind(lsock, (struct sockaddr *) &sa, sizeof(sa))) < 0)
        err_quit("bind");
    
    //go into listen mode
    if( (listen(lsock, 5)) < 0)
        err_quit("listen");
    
    while(1){
        //accept a connection
        if( (asock = accept(lsock, (struct sockaddr *)&csa, &len)) < 0)
            perr_quit("accept");
        
        printf("address is %d.%d.%d.%d\n", NIPQUAD(csa.sin_addr.s_addr) );
        
        if(setsockopt(lsock, SOL_SOCKET, SO_RCVBUF, &rbufsz, sizeof(rbufsz)) != 0)
            perr_quit("setsockopt");
        
        //spawn a thread for each clien
        if(pthread_create(&threadid[x++], NULL, (void *)&f00, (int)asock) != 0)
            perr_quit("pthread");
        
        if(nthreads++ >= MAXTHREADS)
            break;
    }
    
    //wait for all threads
    for(x = 0; x < nthreads; x++)
        if(pthread_join(threadid[x], NULL) < 0)
            perr_quit("pthread join");
    
    //cleanup
    close(lsock);
    
    return 0;
}

#include        <arpa/inet.h>   /* inet(3) functions */
#include        <asm/errno.h>
#include    <asm/ioctl.h>
#include        <errno.h>
#include        <fcntl.h>               /* for nonblocking */
#include        <in_cksum.h>       
#include    <linux/if.h>
#include    <linux/filter.h>    //for socket filters
#include    <linux/socket.h>
#include    <linux/sockios.h>
#include    <net/ethernet.h>       //ether_addr header
#include        <netinet/in_systm.h>
#include        <netinet/ip.h>
#include        <netinet/ip_icmp.h>
#include        <netinet/tcp.h> 
#include        <netinet/udp.h> 
#include        <netinet/in.h>  /* sockaddr_in{} and other Internet defns */
#include        <netdb.h>
#include        <sys/types.h>   /* basic system data types */
#include        <sys/socket.h>  /* basic socket definitions */
#include        <sys/time.h>    /* timeval{} for select() */
#include        <sys/stat.h>    /* for S_xxx file mode constants */
#include        <sys/uio.h>             /* for iovec{} and readv/writev */
#include        <sys/wait.h>
#include        <sys/un.h> 
#include        <signal.h>
#include        <stdio.h>
#include        <stdlib.h>
#include        <string.h>
#include        <unistd.h>

#if __GLIBC__ >= 2 && __GLIBC_MINOR >= 1
       #include <netpacket/packet.h> 
       #include <net/ethernet.h>     /* the L2 protocols */
       #else
       #include <asm/types.h>
       #include <linux/if_packet.h>
       #include <linux/if_ether.h>   /* The L2 protocols */
#endif

//  tcp flags       need to use BSD style tcp header for these #define __FAVOR_BSD to enable it b4 linking 2 library
#define     TCP_FIN     0x01
#define     TCP_SYN     0x02
#define     TCP_RST     0x04
#define     TCP_PUSH    0x08
#define     TCP_ACK     0x10
#define     TCP_URG     0x20

//  internet headers
#define         IP_HDRLEN       20              //duhhh
#define         ICMP_HDRLEN     8
#define         TCP_HDRLEN      20
#define     UDP_HDRLEN  8
#define     ETH_HDRLEN  14

//  useful defines
#define     ETH_BUFSIZE 1500        //max size of ethernet frame w/o header
#define         ADDR_LEN        16              //max len of ascii ip address + NULL terminator

//  LSF OFFSETS these are also useful for otther stuff  as they contain the exact byte offsets off
//          almost all of the header fields. useful to get a value quickly 
#define     LSF_IP_V    0x0 //for consistency   ../ mask 0xf0  }  to get these 4 bit values we use
#define     LSF_IP_HL   0x0 //..            ../ mask 0x0f  }  these masks with bitwise & 
#define     LSF_IP_TOS  0x1
#define     LSF_IP_TL   0x2
#define     LSF_IP_ID   0x4
#define     LSF_IP_FL   0x6
#define     LSF_IP_TTL  0x8
#define     LSF_IP_P    0x9
#define     LSF_IP_CS   0xa
#define     LSF_IP_SIP  0xc
#define     LSF_IP_DIP  0x10

#define     LSF_UDP_SP  0x0
#define     LSF_UDP_DP  0x2
#define     LSF_UDP_L   0x4
#define     LSF_UDP_CS  0x6

#define     LSF_TCP_SP  0x0
#define     LSF_TCP_DP  0x2
#define     LSF_TCP_SQ  0x4
#define     LSF_TCP_AK  0x8
#define     LSF_TCP_HL  0xc
#define     LSF_TCP_FL  0xd
#define     LSF_TCP_WN  0xe
#define     LSF_TCP_CS  0x10
#define     LSF_TCP_UR  0x12

#define     LSF_E_P     0xc

#define     PS_LEN      0xc
//each of these is bitwise OR'ed to match TCP flags
#define FIN_M           0x01    //...notice the pattern? i hope so! since each flag represents a single bit
#define SYN_M           0x02    //we test for the exact number that indicates that power of 2
#define RST_M           0x04
#define PSH_M           0x08
#define ACK_M           0x10
#define URG_M           0x20

//useful port numbers in hex
#define TLNT            0x17            //23            port numbers in hex
#define FTP             0x15            //21
#define SMTP            0x19            //25
#define POP             0x6e            //110
#define TFTP            0x45            //69
#define HTTP        0x50        //80

#define LEN(x) (sizeof(x)/sizeof(struct sock_filter))   //macro for getting code length

//  useful structures       //need to rename pseudohdr to tcp_ps b/c we have a udp one as well to make
struct pseudohdr        //tcp pseudo header used in calculating checksum
{   
    struct in_addr saddr;   //ip source address     04 bytes
        struct in_addr daddr;   //ip destination address    04 bytes
    u_char pad;     //padding           01 bytes
    u_char protocol;    //protocol          01 bytes
    u_short length;     //tcp total length      02 bytes    --->> sum of this 12 bytes
    struct tcphdr tcpheader;    //tcpheader     20 bytes
};

//ripped right from da kernel
/*
 *  *      Display an IP address in readable format.
 *   */

#define NIPQUAD(addr) \
        ((unsigned char *)&addr)[0], \
        ((unsigned char *)&addr)[1], \
        ((unsigned char *)&addr)[2], \
        ((unsigned char *)&addr)[3]

#define HIPQUAD(addr) \
        ((unsigned char *)&addr)[3], \
        ((unsigned char *)&addr)[2], \
        ((unsigned char *)&addr)[1], \
        ((unsigned char *)&addr)[0]