upscheme/c/socket.c

#include <sys/types.h>

#include <sys/select.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in.h>

#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <math.h>
#include <netdb.h>
#include <setjmp.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "scheme.h"

int mysocket(int domain, int type, int protocol)
{
    int val;
    int s = socket(domain, type, protocol);
    if (s < 0)
        return s;
    val = 4096;
    setsockopt(s, SOL_SOCKET, SO_RCVBUF, (char *)&val, sizeof(int));
    val = 4096;
    setsockopt(s, SOL_SOCKET, SO_SNDBUF, (char *)&val, sizeof(int));
    return s;
}

void set_nonblock(int socket, int yes)
{
    int flags;
    flags = fcntl(socket, F_GETFL, 0);
    assert(flags != -1);
    if (yes)
        fcntl(socket, F_SETFL, flags | O_NONBLOCK);
    else
        fcntl(socket, F_SETFL, flags & ~O_NONBLOCK);
}

/* returns a socket on which to accept() connections */
int open_tcp_port(short portno)
{
    int sockfd;
    struct sockaddr_in serv_addr;

    sockfd = mysocket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (sockfd < 0)
        return -1;
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    serv_addr.sin_port = htons(portno);
    if (bind(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
        return -1;
    }

    listen(sockfd, 4);
    return sockfd;
}

/* returns a socket on which to accept() connections, finding some
   available port (portno is value-return) */
int open_any_tcp_port(short *portno)

{
    int sockfd;
    struct sockaddr_in serv_addr;

    sockfd = mysocket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (sockfd < 0)
        return -1;
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    serv_addr.sin_port = htons(*portno);
    while (bind(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) <
           0) {
        (*portno)++;
        serv_addr.sin_port = htons(*portno);
    }

    listen(sockfd, 4);
    return sockfd;
}

/* returns a socket on which to accept() connections, finding some
   available port (portno is value-return) */
int open_any_udp_port(short *portno)
{
    int sockfd;
    struct sockaddr_in serv_addr;

    sockfd = mysocket(PF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0)
        return -1;
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    serv_addr.sin_port = htons(*portno);
    while (bind(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) <
           0) {
        (*portno)++;
        serv_addr.sin_port = htons(*portno);
    }

    return sockfd;
}

#ifndef _WIN32
void closesocket(int fd) { close(fd); }
#endif

/* returns a socket to use to send data to the given address */
int connect_to_host(char *hostname, short portno)
{
    struct hostent *host_info;
    int sockfd, yes = 1;
    struct sockaddr_in host_addr;

    host_info = gethostbyname(hostname);
    if (host_info == NULL) {
        return -1;
    }

    sockfd = mysocket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (sockfd < 0) {
        return -1;
    }
    (void)setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));
    memset((char *)&host_addr, 0, sizeof(host_addr));
    host_addr.sin_family = host_info->h_addrtype;
    memcpy((char *)&host_addr.sin_addr, host_info->h_addr,
           host_info->h_length);

    host_addr.sin_port = htons(portno);

    if (connect(sockfd, (struct sockaddr *)&host_addr,
                sizeof(struct sockaddr_in)) != 0) {
        closesocket(sockfd);
        return -1;
    }

    return sockfd;
}

int connect_to_addr(struct sockaddr_in *host_addr)
{
    int sockfd, yes = 1;

    sockfd = mysocket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (sockfd < 0) {
        return -1;
    }
    (void)setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));

    if (connect(sockfd, (struct sockaddr *)host_addr,
                sizeof(struct sockaddr_in)) != 0) {
        closesocket(sockfd);
        return -1;
    }

    return sockfd;
}

/* repeated send until all of buffer is sent */
int sendall(int sockfd, char *buffer, int bufLen, int flags)
{
    int numBytesToSend = bufLen, length;

    while (numBytesToSend > 0) {
        length = send(sockfd, (void *)buffer, numBytesToSend, flags);
        if (length < 0) {
            return (-1);
        }
        numBytesToSend -= length;
        buffer += length;
    }
    return (bufLen);
}

/* repeated read until all of buffer is read */
int readall(int sockfd, char *buffer, int bufLen, int flags)
{
    int numBytesToRead = bufLen, length;

    while (numBytesToRead > 0) {
        length = recv(sockfd, buffer, numBytesToRead, flags);
        if (length <= 0) {
            return (length);
        }
        numBytesToRead -= length;
        buffer += length;
    }
    return (bufLen);
}

int addr_eq(struct sockaddr_in *a, struct sockaddr_in *b)
{
    if (a->sin_port == b->sin_port &&
        a->sin_addr.s_addr == b->sin_addr.s_addr)
        return 1;
    return 0;
}

int socket_ready(int sock)
{
    fd_set fds;
    struct timeval timeout;

    timeout.tv_sec = 0;
    timeout.tv_usec = 1000;

    FD_ZERO(&fds);
    FD_SET(sock, &fds);
    select(sock + 1, &fds, NULL, NULL, &timeout);
    return FD_ISSET(sock, &fds);
}