/* Updated 4/18/13 droh: * rio_readlineb: fixed edge case bug * rio_readnb: removed redundant EINTR check */ /* $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) 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') { 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; } /* $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 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; } /******************************** * Client/server helper functions ********************************/ /* * open_clientfd - open connection to server at * 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"); else dns_error("Open_clientfd DNS error"); } return rc; } int Open_listenfd(int port) { int rc; if ((rc = open_listenfd(port)) < 0) unix_error("Open_listenfd error"); return rc; } /* $end csapp.c */
