*/
#include "os_file.h"
+#include "detect_os.h"
#include <errno.h>
+#include <fcntl.h>
#include <stdlib.h>
+#include <sys/stat.h>
+
+#if DETECT_OS_WINDOWS
+#include <io.h>
+#define open _open
+#define fdopen _fdopen
+#define O_CREAT _O_CREAT
+#define O_EXCL _O_EXCL
+#define O_WRONLY _O_WRONLY
+#else
+#include <unistd.h>
+#ifndef F_DUPFD_CLOEXEC
+#define F_DUPFD_CLOEXEC 1030
+#endif
+#endif
+
+
+FILE *
+os_file_create_unique(const char *filename, int filemode)
+{
+ int fd = open(filename, O_CREAT | O_EXCL | O_WRONLY, filemode);
+ if (fd == -1)
+ return NULL;
+ return fdopen(fd, "w");
+}
+
+
+#if DETECT_OS_WINDOWS
+int
+os_dupfd_cloexec(int fd)
+{
+ /*
+ * On Windows child processes don't inherit handles by default:
+ * https://devblogs.microsoft.com/oldnewthing/20111216-00/?p=8873
+ */
+ return dup(fd);
+}
+#else
+int
+os_dupfd_cloexec(int fd)
+{
+ int minfd = 3;
+ int newfd = fcntl(fd, F_DUPFD_CLOEXEC, minfd);
+
+ if (newfd >= 0)
+ return newfd;
-#if defined(__linux__)
+ if (errno != EINVAL)
+ return -1;
+
+ newfd = fcntl(fd, F_DUPFD, minfd);
+
+ if (newfd < 0)
+ return -1;
+
+ long flags = fcntl(newfd, F_GETFD);
+ if (flags == -1) {
+ close(newfd);
+ return -1;
+ }
+
+ if (fcntl(newfd, F_SETFD, flags | FD_CLOEXEC) == -1) {
+ close(newfd);
+ return -1;
+ }
+
+ return newfd;
+}
+#endif
+
+
+#if DETECT_OS_LINUX
#include <fcntl.h>
#include <sys/stat.h>
+#include <sys/syscall.h>
#include <unistd.h>
+/* copied from <linux/kcmp.h> */
+#define KCMP_FILE 0
static ssize_t
readN(int fd, char *buf, size_t len)
if (ret == -EINTR || ret == -EAGAIN)
continue;
- if (ret <= 0)
+ if (ret <= 0) {
+ err = ret;
break;
+ }
total += ret;
} while (total != len);
- return total ? total : err;
+ return total ? (ssize_t)total : err;
}
-static char *
-read_grow(int fd)
+char *
+os_read_file(const char *filename, size_t *size)
{
+ /* Note that this also serves as a slight margin to avoid a 2x grow when
+ * the file is just a few bytes larger when we read it than when we
+ * fstat'ed it.
+ * The string's NULL terminator is also included in here.
+ */
size_t len = 64;
+ int fd = open(filename, O_RDONLY);
+ if (fd == -1) {
+ /* errno set by open() */
+ return NULL;
+ }
+
+ /* Pre-allocate a buffer at least the size of the file if we can read
+ * that information.
+ */
+ struct stat stat;
+ if (fstat(fd, &stat) == 0)
+ len += stat.st_size;
+
char *buf = malloc(len);
if (!buf) {
close(fd);
return NULL;
}
- ssize_t read;
+ ssize_t actually_read;
size_t offset = 0, remaining = len - 1;
- while ((read = readN(fd, buf + offset, remaining)) == remaining) {
+ while ((actually_read = readN(fd, buf + offset, remaining)) == (ssize_t)remaining) {
char *newbuf = realloc(buf, 2 * len);
if (!newbuf) {
free(buf);
buf = newbuf;
len *= 2;
- offset += read;
+ offset += actually_read;
remaining = len - offset - 1;
}
close(fd);
- if (read > 0)
- offset += read;
-
- buf[offset] = '\0';
-
- return buf;
-}
-
-char *
-os_read_file(const char *filename)
-{
- size_t len = 0;
-
- int fd = open(filename, O_RDONLY);
- if (fd == -1) {
- /* errno set by open() */
- return NULL;
- }
-
- struct stat stat;
- if (fstat(fd, &stat) == 0)
- len = stat.st_size;
-
- if (!len)
- return read_grow(fd);
-
- /* add NULL terminator */
- len++;
+ if (actually_read > 0)
+ offset += actually_read;
- char *buf = malloc(len);
- if (!buf) {
- close(fd);
+ /* Final resize to actual size */
+ len = offset + 1;
+ char *newbuf = realloc(buf, len);
+ if (!newbuf) {
+ free(buf);
errno = -ENOMEM;
return NULL;
}
+ buf = newbuf;
- ssize_t read = readN(fd, buf, len - 1);
+ buf[offset] = '\0';
- close(fd);
+ if (size)
+ *size = offset;
- if (read == -1)
- return NULL;
+ return buf;
+}
- buf[read] = '\0';
+int
+os_same_file_description(int fd1, int fd2)
+{
+ pid_t pid = getpid();
- return buf;
+ /* Same file descriptor trivially implies same file description */
+ if (fd1 == fd2)
+ return 0;
+
+ return syscall(SYS_kcmp, pid, pid, KCMP_FILE, fd1, fd2);
}
#else
+#include "u_debug.h"
+
char *
-os_read_file(const char *filename)
+os_read_file(const char *filename, size_t *size)
{
errno = -ENOSYS;
return NULL;
}
+int
+os_same_file_description(int fd1, int fd2)
+{
+ /* Same file descriptor trivially implies same file description */
+ if (fd1 == fd2)
+ return 0;
+
+ /* Otherwise we can't tell */
+ return -1;
+}
+
#endif