util.c

#include "util.h"

void unix_error(char *msg) /* Unix-style error */
{
    fprintf(stderr, "%s: %s\n", msg, strerror(errno));
    exit(0);
}

void gai_error(int code, char *msg) /* Getaddrinfo-style error */
{
    fprintf(stderr, "%s: %s\n", msg, gai_strerror(code));
    exit(0);
}

pid_t Fork(void) 
{
    pid_t pid;

    if ((pid = fork()) < 0)
	unix_error("Fork error");
    return pid;
}

void Execve(const char *filename, char *const argv[], char *const envp[]) 
{
    if (execve(filename, argv, envp) < 0)
	unix_error("Execve error");
}

pid_t Wait(int *status) 
{
    pid_t pid;

    if ((pid  = wait(status)) < 0)
	unix_error("Wait error");
    return pid;
}

void *Mmap(void *addr, size_t len, int prot, int flags, int fd, off_t offset) 
{
    void *ptr;

    if ((ptr = mmap(addr, len, prot, flags, fd, offset)) == ((void *) -1))
	unix_error("mmap error");
    return(ptr);
}

void Munmap(void *start, size_t length) 
{
    if (munmap(start, length) < 0)
	unix_error("munmap error");
}

int Open(const char *pathname, int flags, mode_t mode) 
{
    int rc;

    if ((rc = open(pathname, flags, mode))  < 0)
	unix_error("Open error");
    return rc;
}

void Close(int fd) 
{
    int rc;

    if ((rc = close(fd)) < 0)
	unix_error("Close error");
}

int Dup2(int fd1, int fd2) 
{
    int rc;

    if ((rc = dup2(fd1, fd2)) < 0)
	unix_error("Dup2 error");
    return rc;
}

int Socket(int domain, int type, int protocol) 
{
    int rc;

    if ((rc = socket(domain, type, protocol)) < 0)
	unix_error("Socket error");
    return rc;
}

void Setsockopt(int s, int level, int optname, const void *optval, int optlen) 
{
    int rc;

    if ((rc = setsockopt(s, level, optname, optval, optlen)) < 0)
	unix_error("Setsockopt error");
}

void Bind(int sockfd, struct sockaddr *my_addr, int addrlen) 
{
    int rc;

    if ((rc = bind(sockfd, my_addr, addrlen)) < 0)
	unix_error("Bind error");
}

void Listen(int s, int backlog) 
{
    int rc;

    if ((rc = listen(s,  backlog)) < 0)
	unix_error("Listen error");
}

int Accept(int s, struct sockaddr *addr, socklen_t *addrlen) 
{
    int rc;

    if ((rc = accept(s, addr, addrlen)) < 0)
	unix_error("Accept error");
    return rc;
}

void Connect(int sockfd, struct sockaddr *serv_addr, int addrlen) 
{
    int rc;

    if ((rc = connect(sockfd, serv_addr, addrlen)) < 0)
	unix_error("Connect error");
}

void Getnameinfo(const struct sockaddr *sa, socklen_t salen, char *host, size_t hostlen, char *serv, size_t servlen, int flags)
{
    int rc;

    if ((rc = getnameinfo(sa, salen, host, hostlen, serv, 
                          servlen, flags)) != 0) 
        gai_error(rc, "Getnameinfo error");
}

ssize_t rio_readn(int fd, void *usrbuf, size_t n) 
{
    size_t nleft = n;
    ssize_t nread;
    char *bufp = usrbuf;

    while (nleft > 0) {
	if ((nread = read(fd, bufp, nleft)) < 0) {
	    if (errno == EINTR) /* Interrupted by sig handler return */
		nread = 0;      /* and call read() again */
	    else
		return -1;      /* errno set by read() */ 
	} 
	else if (nread == 0)
	    break;              /* EOF */
	nleft -= nread;
	bufp += nread;
    }
    return (n - nleft);         /* return >= 0 */
}

void Getaddrinfo(const char *node, const char *service, 
                 const struct addrinfo *hints, struct addrinfo **res)
{
    int rc;

    if ((rc = getaddrinfo(node, service, hints, res)) != 0) 
        gai_error(rc, "Getaddrinfo error");
}

void Freeaddrinfo(struct addrinfo *res)
{
    freeaddrinfo(res);
}

ssize_t rio_writen(int fd, void *usrbuf, size_t n) 
{
    size_t nleft = n;
    ssize_t nwritten;
    char *bufp = usrbuf;

    while (nleft > 0) {
	if ((nwritten = write(fd, bufp, nleft)) <= 0) {
	    if (errno == EINTR)  /* Interrupted by sig handler return */
		nwritten = 0;    /* and call write() again */
	    else
		return -1;       /* errno set by write() */
	}
	nleft -= nwritten;
	bufp += nwritten;
    }
    return n;
}

static ssize_t rio_read(rio_t *rp, char *usrbuf, size_t n)
{
    int cnt;

    while (rp->rio_cnt <= 0) {  /* Refill if buf is empty */
	rp->rio_cnt = read(rp->rio_fd, rp->rio_buf, 
			   sizeof(rp->rio_buf));
	if (rp->rio_cnt < 0) {
	    if (errno != EINTR) /* Interrupted by sig handler return */
		return -1;
	}
	else if (rp->rio_cnt == 0)  /* EOF */
	    return 0;
	else 
	    rp->rio_bufptr = rp->rio_buf; /* Reset buffer ptr */
    }

    /* Copy min(n, rp->rio_cnt) bytes from internal buf to user buf */
    cnt = n;          
    if (rp->rio_cnt < n)   
	cnt = rp->rio_cnt;
    memcpy(usrbuf, rp->rio_bufptr, cnt);
    rp->rio_bufptr += cnt;
    rp->rio_cnt -= cnt;
    return cnt;
}

void rio_readinitb(rio_t *rp, int fd) 
{
    rp->rio_fd = fd;  
    rp->rio_cnt = 0;  
    rp->rio_bufptr = rp->rio_buf;
}

ssize_t rio_readnb(rio_t *rp, void *usrbuf, size_t n) 
{
    size_t nleft = n;
    ssize_t nread;
    char *bufp = usrbuf;
    
    while (nleft > 0) {
	if ((nread = rio_read(rp, bufp, nleft)) < 0) 
            return -1;          /* errno set by read() */ 
	else if (nread == 0)
	    break;              /* EOF */
	nleft -= nread;
	bufp += nread;
    }
    return (n - nleft);         /* return >= 0 */
}

ssize_t rio_readlineb(rio_t *rp, void *usrbuf, size_t maxlen) 
{
    int n, rc;
    char c, *bufp = usrbuf;

    for (n = 1; n < maxlen; n++) { 
        if ((rc = rio_read(rp, &c, 1)) == 1) {
	    *bufp++ = c;
	    if (c == '\n') {
                n++;
     		break;
            }
	} else if (rc == 0) {
	    if (n == 1) {
		return 0; /* EOF, no data read */
            }
	    else {
		break;    /* EOF, some data was read */
            }
	} else
	    return -1;	  /* Error */
    }
    *bufp = '\0';
    return n-1;
}

ssize_t Rio_readn(int fd, void *ptr, size_t nbytes) 
{
    ssize_t n;
  
    if ((n = rio_readn(fd, ptr, nbytes)) < 0)
	unix_error("Rio_readn error");
    return n;
}

void Rio_writen(int fd, void *usrbuf, size_t n) 
{
    if (rio_writen(fd, usrbuf, n) != n)
	unix_error("Rio_writen error");
}

void Rio_readinitb(rio_t *rp, int fd)
{
    rio_readinitb(rp, fd);
} 

ssize_t Rio_readnb(rio_t *rp, void *usrbuf, size_t n) 
{
    ssize_t rc;

    if ((rc = rio_readnb(rp, usrbuf, n)) < 0)
	unix_error("Rio_readnb error");
    return rc;
}

ssize_t Rio_readlineb(rio_t *rp, void *usrbuf, size_t maxlen) 
{
    ssize_t rc;

    if ((rc = rio_readlineb(rp, usrbuf, maxlen)) < 0)
	unix_error("Rio_readlineb error");
    return rc;
} 

int open_listenfd(char *port) 
{
    struct addrinfo hints, *listp, *p;
    int listenfd, optval=1;

    /* Get a list of potential server addresses */
    memset(&hints, 0, sizeof(struct addrinfo));
    hints.ai_socktype = SOCK_STREAM;  /* Accept TCP connections */
    hints.ai_flags = AI_PASSIVE;      /* ... on any IP address */
    hints.ai_flags |= AI_NUMERICSERV; /* ... using a numeric port arg. */
    hints.ai_flags |= AI_ADDRCONFIG;  /* Recommended for connections */
    Getaddrinfo(NULL, port, &hints, &listp);

    /* Walk the list for one that we can bind to */
    for (p = listp; p; p = p->ai_next) {

        /* Create a socket descriptor */
        if ((listenfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) < 0) 
            continue;  /* Socket failed, try the next */

        /* Eliminates "Address already in use" error from bind */
        Setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, 
                   (const void *)&optval , sizeof(int));

        /* Bind the descriptor to the address */
        if (bind(listenfd, p->ai_addr, p->ai_addrlen) == 0)
            break; /* Success */
        Close(listenfd); /* Bind failed, try the next */
    }

    /* Clean up */
    Freeaddrinfo(listp);
    if (!p) /* No address worked */
        return -1;

    /* Make it a listening socket ready to accept connection requests */
    if (listen(listenfd, LISTENQ) < 0)
	return -1;
    return listenfd;
}

int Open_listenfd(char *port) 
{
    int rc;

    if ((rc = open_listenfd(port)) < 0)
	unix_error("Open_listenfd error");
    return rc;
}