+/*
+ * Copyright (C) 2006-2007 Andre Noll <maan@systemlinux.org>
+ *
+ * Licensed under the GPL v2. For licencing details see COPYING.
+ */
+
+/** \file fd.c helper functions for file descriptor handling */
+
#include "para.h"
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <sys/select.h>
+
#include "error.h"
/**
* check whether a file exists
return !stat(fn, &statbuf);
}
+/**
+ * paraslash's wrapper for select(2)
+ *
+ * It calls select(2) (with no exceptfds) and starts over if select() was
+ * interrupted by a signal.
+ *
+ * \param n the highest-numbered descriptor in any of the two sets, plus 1
+ * \param readfds fds that should be checked for readability
+ * \param writefds fds that should be checked for writablility
+ * \param timeout_tv upper bound on the amount of time elapsed before select()
+ * returns
+ *
+ * \return The return value of the underlying select() call.
+ *
+ * All arguments are passed verbatim to select(2).
+ * \sa select(2) select_tut(2)
+ */
int para_select(int n, fd_set *readfds, fd_set *writefds,
- struct timeval *timeout)
+ struct timeval *timeout_tv)
{
int ret, err;
do {
- ret = select(n, readfds, writefds, NULL, timeout);
+ ret = select(n, readfds, writefds, NULL, timeout_tv);
err = errno;
- } while (ret < 0 && errno == EINTR);
- if (ret < 0)
- PARA_CRIT_LOG("select error (%s)\n", strerror(err));
+ } while (ret < 0 && err == EINTR);
+ if (ret < 0) {
+ PARA_CRIT_LOG("select error: %s, max_fileno: %d\n",
+ strerror(err), n);
+ ret = -E_SELECT;
+ }
return ret;
}
+/**
+ * set a file descriptor to non-blocking mode
+ *
+ * \param fd The file descriptor
+ *
+ * \returns 1 on success, -E_F_GETFL, -E_F_SETFL, on errors.
+ */
int mark_fd_nonblock(int fd)
{
int flags = fcntl(fd, F_GETFL);
return 1;
}
+/**
+ * set a file descriptor in a fd_set
+ *
+ * \param fd the file descriptor to be set
+ * \param fds the file descriptor set
+ * \param max_fileno highest-numbered file descriptor
+ *
+ * This wrapper for FD_SET() passes its first two arguments to \p FD_SET. Upon
+ * return, \a max_fileno contains the maximum of the old_value and \a fd.
+ *
+ * \sa para_select
+*/
+void para_fd_set(int fd, fd_set *fds, int *max_fileno)
+{
+
+ if (fd < 0 || fd >= FD_SETSIZE) {
+ PARA_EMERG_LOG("fatal: tried to add invalid fd %d\n", fd);
+ exit(EXIT_FAILURE);
+ }
+#if 0
+ {
+ int flags = fcntl(fd, F_GETFL);
+ if (!(flags & O_NONBLOCK)) {
+ PARA_EMERG_LOG("fd %d is a blocking file descriptor\n", fd);
+ exit(EXIT_FAILURE);
+ }
+ }
+#endif
+ FD_SET(fd, fds);
+ *max_fileno = PARA_MAX(*max_fileno, fd);
+}
+
+/**
+* paraslash's wrapper for fgets(3)
+* \param line pointer to the buffer to store the line
+* \param size the size of the buffer given by \a line
+* \param f the stream to read from
+*
+* \return Unlike the standard fgets() function, an integer value
+* is returned. On success, this function returns 1. On errors, -E_FGETS
+* is returned. A zero return value indicates an end of file condition.
+*/
+__must_check int para_fgets(char *line, int size, FILE *f)
+{
+again:
+ if (fgets(line, size, f))
+ return 1;
+ if (feof(f))
+ return 0;
+ if (!ferror(f))
+ return -E_FGETS;
+ if (errno != EINTR) {
+ PARA_ERROR_LOG("%s\n", strerror(errno));
+ return -E_FGETS;
+ }
+ clearerr(f);
+ goto again;
+}
+
+/**
+ * *paraslash's wrapper for mmap
+ *
+ * \param length number of bytes to mmap
+ * \param prot either PROT_NONE or the bitwise OR of one or more of
+ * PROT_EXEC PROT_READ PROT_WRITE
+ * \param flags exactly one of MAP_SHARED and MAP_PRIVATE
+ * \param fd the file to mmap from
+ * \param offset mmap start
+ *
+ * \return This function either returns a valid pointer to the mapped area
+ * or calls exit() on errors.
+ */
+void *para_mmap(size_t length, int prot, int flags, int fd, off_t offset)
+{
+ void *ret = mmap(NULL, length, prot, flags, fd, offset);
+ if (ret != MAP_FAILED)
+ return ret;
+ PARA_EMERG_LOG("mmap failed: %s\n", strerror(errno));
+ PARA_EMERG_LOG("length: %zu, flags: %d, fd: %d, offset: %zu\n",
+ length, flags, fd, (size_t)offset);
+ exit(EXIT_FAILURE);
+}
+