Subversion Repositories Code-Repo

/* $begin csapp.c */

#include "csapp.h"

/************************** 

 * Error-handling functions

 **************************/

/* $begin errorfuns */

/* $begin unixerror */

void unix_error(char *msg) /* unix-style error */

{

    fprintf(stderr, "%s: %s\n", msg, strerror(errno));

    // exit(0);

}

/* $end unixerror */

void posix_error(int code, char *msg) /* posix-style error */

{

    fprintf(stderr, "%s: %s\n", msg, strerror(code));

    // exit(0);

}

void dns_error(char *msg) /* dns-style error */

{

    fprintf(stderr, "%s: DNS error %d\n", msg, h_errno);

    // exit(0);

}

void app_error(char *msg) /* application error */

{

    fprintf(stderr, "%s\n", msg);

    // exit(0);

}

/* $end errorfuns */

/*********************************************

 * Wrappers for Unix process control functions

 ********************************************/

/* $begin forkwrapper */

pid_t Fork(void) 

{

    pid_t pid;

    if ((pid = fork()) < 0)

	unix_error("Fork error");

    return pid;

}

/* $end forkwrapper */

void Execve(const char *filename, char *const argv[], char *const envp[]) 

{

    if (execve(filename, argv, envp) < 0)

	unix_error("Execve error");

}

/* $begin wait */

pid_t Wait(int *status) 

{

    pid_t pid;

    if ((pid  = wait(status)) < 0)

	unix_error("Wait error");

    return pid;

}

/* $end wait */

pid_t Waitpid(pid_t pid, int *iptr, int options) 

{

    pid_t retpid;

    if ((retpid  = waitpid(pid, iptr, options)) < 0) 

	unix_error("Waitpid error");

    return(retpid);

}

/* $begin kill */

void Kill(pid_t pid, int signum) 

{

    int rc;

    if ((rc = kill(pid, signum)) < 0)

	unix_error("Kill error");

}

/* $end kill */

void Pause() 

{

    (void)pause();

    return;

}

unsigned int Sleep(unsigned int secs) 

{

    unsigned int rc;

    if ((rc = sleep(secs)) < 0)

	unix_error("Sleep error");

    return rc;

}

unsigned int Alarm(unsigned int seconds) {

    return alarm(seconds);

}

void Setpgid(pid_t pid, pid_t pgid) {

    int rc;

    if ((rc = setpgid(pid, pgid)) < 0)

	unix_error("Setpgid error");

    return;

}

pid_t Getpgrp(void) {

    return getpgrp();

}

/************************************

 * Wrappers for Unix signal functions 

 ***********************************/

/* $begin sigaction */

handler_t *Signal(int signum, handler_t *handler) 

{

    struct sigaction action, old_action;

    action.sa_handler = handler;  

    sigemptyset(&action.sa_mask); /* block sigs of type being handled */

    action.sa_flags = SA_RESTART; /* restart syscalls if possible */

    if (sigaction(signum, &action, &old_action) < 0)

	unix_error("Signal error");

    return (old_action.sa_handler);

}

/* $end sigaction */

void Sigprocmask(int how, const sigset_t *set, sigset_t *oldset)

{

    if (sigprocmask(how, set, oldset) < 0)

	unix_error("Sigprocmask error");

    return;

}

void Sigemptyset(sigset_t *set)

{

    if (sigemptyset(set) < 0)

	unix_error("Sigemptyset error");

    return;

}

void Sigfillset(sigset_t *set)

{ 

    if (sigfillset(set) < 0)

	unix_error("Sigfillset error");

    return;

}

void Sigaddset(sigset_t *set, int signum)

{

    if (sigaddset(set, signum) < 0)

	unix_error("Sigaddset error");

    return;

}

void Sigdelset(sigset_t *set, int signum)

{

    if (sigdelset(set, signum) < 0)

	unix_error("Sigdelset error");

    return;

}

int Sigismember(const sigset_t *set, int signum)

{

    int rc;

    if ((rc = sigismember(set, signum)) < 0)

	unix_error("Sigismember error");

    return rc;

}

/********************************

 * Wrappers for Unix I/O routines

 ********************************/

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;

}

ssize_t Read(int fd, void *buf, size_t count) 

{

    ssize_t rc;

    if ((rc = read(fd, buf, count)) < 0) 

	unix_error("Read error");

    return rc;

}

ssize_t Write(int fd, const void *buf, size_t count) 

{

    ssize_t rc;

    if ((rc = write(fd, buf, count)) < 0)

	unix_error("Write error");

    return rc;

}

off_t Lseek(int fildes, off_t offset, int whence) 

{

    off_t rc;

    if ((rc = lseek(fildes, offset, whence)) < 0)

	unix_error("Lseek error");

    return rc;

}

void Close(int fd) 

{

    int rc;

    if ((rc = close(fd)) < 0)

	unix_error("Close error");

}

int Select(int  n, fd_set *readfds, fd_set *writefds,

	   fd_set *exceptfds, struct timeval *timeout) 

{

    int rc;

    if ((rc = select(n, readfds, writefds, exceptfds, timeout)) < 0)

	unix_error("Select error");

    return rc;

}

int Dup2(int fd1, int fd2) 

{

    int rc;

    if ((rc = dup2(fd1, fd2)) < 0)

	unix_error("Dup2 error");

    return rc;

}

void Stat(const char *filename, struct stat *buf) 

{

    if (stat(filename, buf) < 0)

	unix_error("Stat error");

}

void Fstat(int fd, struct stat *buf) 

{

    if (fstat(fd, buf) < 0)

	unix_error("Fstat error");

}

/***************************************

 * Wrappers for memory mapping functions

 ***************************************/

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");

}

/***************************************************

 * Wrappers for dynamic storage allocation functions

 ***************************************************/

void *Malloc(size_t size) 

{

    void *p;

    if ((p  = malloc(size)) == NULL)

	unix_error("Malloc error");

    return p;

}

void *Realloc(void *ptr, size_t size) 

{

    void *p;

    if ((p  = realloc(ptr, size)) == NULL)

	unix_error("Realloc error");

    return p;

}

void *Calloc(size_t nmemb, size_t size) 

{

    void *p;

    if ((p = calloc(nmemb, size)) == NULL)

	unix_error("Calloc error");

    return p;

}

void Free(void *ptr) 

{

    free(ptr);

}

/******************************************

 * Wrappers for the Standard I/O functions.

 ******************************************/

void Fclose(FILE *fp) 

{

    if (fclose(fp) != 0)

	unix_error("Fclose error");

}

FILE *Fdopen(int fd, const char *type) 

{

    FILE *fp;

    if ((fp = fdopen(fd, type)) == NULL)

	unix_error("Fdopen error");

    return fp;

}

char *Fgets(char *ptr, int n, FILE *stream) 

{

    char *rptr;

    if (((rptr = fgets(ptr, n, stream)) == NULL) && ferror(stream))

	app_error("Fgets error");

    return rptr;

}

FILE *Fopen(const char *filename, const char *mode) 

{

    FILE *fp;

    if ((fp = fopen(filename, mode)) == NULL)

	unix_error("Fopen error");

    return fp;

}

void Fputs(const char *ptr, FILE *stream) 

{

    if (fputs(ptr, stream) == EOF)

	unix_error("Fputs error");

}

size_t Fread(void *ptr, size_t size, size_t nmemb, FILE *stream) 

{

    size_t n;

    if (((n = fread(ptr, size, nmemb, stream)) < nmemb) && ferror(stream)) 

	unix_error("Fread error");

    return n;

}

void Fwrite(const void *ptr, size_t size, size_t nmemb, FILE *stream) 

{

    if (fwrite(ptr, size, nmemb, stream) < nmemb)

	unix_error("Fwrite error");

}

/**************************** 

 * Sockets interface wrappers

 ****************************/

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");

}

/************************

 * DNS interface wrappers 

 ***********************/

/* $begin gethostbyname */

struct hostent *Gethostbyname(const char *name) 

{

    struct hostent *p;

    if ((p = gethostbyname(name)) == NULL)

	dns_error("Gethostbyname error");

    return p;

}

/* $end gethostbyname */

struct hostent *Gethostbyaddr(const char *addr, int len, int type) 

{

    struct hostent *p;

    if ((p = gethostbyaddr(addr, len, type)) == NULL)

	dns_error("Gethostbyaddr error");

    return p;

}

/************************************************

 * Wrappers for Pthreads thread control functions

 ************************************************/

void Pthread_create(pthread_t *tidp, pthread_attr_t *attrp, 

		    void * (*routine)(void *), void *argp) 

{

    int rc;

    if ((rc = pthread_create(tidp, attrp, routine, argp)) != 0)

	posix_error(rc, "Pthread_create error");

}

void Pthread_cancel(pthread_t tid) {

    int rc;

    if ((rc = pthread_cancel(tid)) != 0)

	posix_error(rc, "Pthread_cancel error");

}

void Pthread_join(pthread_t tid, void **thread_return) {

    int rc;

    if ((rc = pthread_join(tid, thread_return)) != 0)

	posix_error(rc, "Pthread_join error");

}

/* $begin detach */

void Pthread_detach(pthread_t tid) {

    int rc;

    if ((rc = pthread_detach(tid)) != 0)

	posix_error(rc, "Pthread_detach error");

}

/* $end detach */

void Pthread_exit(void *retval) {

    pthread_exit(retval);

}

pthread_t Pthread_self(void) {

    return pthread_self();

}

void Pthread_once(pthread_once_t *once_control, void (*init_function)()) {

    pthread_once(once_control, init_function);

}

/*******************************

 * Wrappers for Posix semaphores

 *******************************/

void Sem_init(sem_t *sem, int pshared, unsigned int value) 

{

    if (sem_init(sem, pshared, value) < 0)

	unix_error("Sem_init error");

}

void P(sem_t *sem) 

{

    if (sem_wait(sem) < 0)

	unix_error("P error");

}

void V(sem_t *sem) 

{

    if (sem_post(sem) < 0)

	unix_error("V error");

}

/*********************************************************************

 * The Rio package - robust I/O functions

 **********************************************************************/

/*

 * rio_readn - robustly read n bytes (unbuffered)

 */

/* $begin rio_readn */

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 */

}

/* $end rio_readn */

/*

 * rio_writen - robustly write n bytes (unbuffered)

 */

/* $begin rio_writen */

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;

}

/* $end rio_writen */

/* 

 * rio_read - This is a wrapper for the Unix read() function that

 *    transfers min(n, rio_cnt) bytes from an internal buffer to a user

 *    buffer, where n is the number of bytes requested by the user and

 *    rio_cnt is the number of unread bytes in the internal buffer. On

 *    entry, rio_read() refills the internal buffer via a call to

 *    read() if the internal buffer is empty.

 */

/* $begin rio_read */

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;

}

/* $end rio_read */

/*

 * rio_readinitb - Associate a descriptor with a read buffer and reset buffer

 */

/* $begin rio_readinitb */

void rio_readinitb(rio_t *rp, int fd) 

{

    rp->rio_fd = fd;  

    rp->rio_cnt = 0;  

    rp->rio_bufptr = rp->rio_buf;

}

/* $end rio_readinitb */

/*

 * rio_readnb - Robustly read n bytes (buffered)

 */

/* $begin rio_readnb */

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) {

	    if (errno == EINTR) /* interrupted by sig handler return */

		nread = 0;      /* 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 */

}

/* $end rio_readnb */

/* 

 * rio_readlineb - robustly read a text line (buffered)

 */

/* $begin rio_readlineb */

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')

		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;

}

/* $end rio_readlineb */

/**********************************

 * Wrappers for robust I/O routines

 **********************************/

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 -1;

    }

    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 -1;

    }

    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 -1;

    }

    return rc;

} 

/******************************** 

 * Client/server helper functions

 ********************************/

/*

 * open_clientfd - open connection to server at <hostname, port> 

 *   and return a socket descriptor ready for reading and writing.

 *   Returns -1 and sets errno on Unix error. 

 *   Returns -2 and sets h_errno on DNS (gethostbyname) error.

 */

/* $begin open_clientfd */

int open_clientfd(char *hostname, int port) 

{

    int clientfd;

    struct hostent *hp;

    struct sockaddr_in serveraddr;

    if ((clientfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)

	return -1; /* check errno for cause of error */

    /* Fill in the server's IP address and port */

    if ((hp = gethostbyname(hostname)) == NULL)

	return -2; /* check h_errno for cause of error */

    bzero((char *) &serveraddr, sizeof(serveraddr));

    serveraddr.sin_family = AF_INET;

    bcopy((char *)hp->h_addr_list[0], 

	  (char *)&serveraddr.sin_addr.s_addr, hp->h_length);

    serveraddr.sin_port = htons(port);

    /* Establish a connection with the server */

    if (connect(clientfd, (SA *) &serveraddr, sizeof(serveraddr)) < 0)

	return -1;

    return clientfd;

}

/* $end open_clientfd */

/*  

 * open_listenfd - open and return a listening socket on port

 *     Returns -1 and sets errno on Unix error.

 */

/* $begin open_listenfd */

int open_listenfd(int port) 

{

    int listenfd, optval=1;

    struct sockaddr_in serveraddr;

    /* Create a socket descriptor */

    if ((listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)

	return -1;

    /* Eliminates "Address already in use" error from bind. */

    if (setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, 

		   (const void *)&optval , sizeof(int)) < 0)

	return -1;

    /* Listenfd will be an endpoint for all requests to port

       on any IP address for this host */

    bzero((char *) &serveraddr, sizeof(serveraddr));

    serveraddr.sin_family = AF_INET; 

    serveraddr.sin_addr.s_addr = htonl(INADDR_ANY); 

    serveraddr.sin_port = htons((unsigned short)port); 

    if (bind(listenfd, (SA *)&serveraddr, sizeof(serveraddr)) < 0)

	return -1;

    /* Make it a listening socket ready to accept connection requests */

    if (listen(listenfd, LISTENQ) < 0)

	return -1;

    return listenfd;

}

/* $end open_listenfd */

/******************************************

 * Wrappers for the client/server helper routines 

 ******************************************/

int Open_clientfd(char *hostname, int port) 

{

    int rc;

    if ((rc = open_clientfd(hostname, port)) < 0) {

    	if (rc == -1) {

    	    unix_error("Open_clientfd Unix error");

            return -1;

        } else {

    	    dns_error("Open_clientfd DNS error");

            return -1;

        }

    }

    return rc;

}

int Open_listenfd(int port) 

{

    int rc;

    if ((rc = open_listenfd(port)) < 0) {

        unix_error("Open_listenfd error");

        return -1; 

    }

    return rc;

}

/* $end csapp.c */