diff options
Diffstat (limited to 'man7/fanotify.7')
| -rw-r--r-- | man7/fanotify.7 | 165 |
1 files changed, 82 insertions, 83 deletions
diff --git a/man7/fanotify.7 b/man7/fanotify.7 index 9026375be..7c72a2996 100644 --- a/man7/fanotify.7 +++ b/man7/fanotify.7 @@ -1030,7 +1030,7 @@ Press enter key to terminate. Listening for events. FAN_OPEN_PERM: File /home/user/temp/notes FAN_CLOSE_WRITE: File /home/user/temp/notes - +\& Listening for events stopped. .EE .in @@ -1046,9 +1046,9 @@ Listening for events stopped. #include <stdlib.h> #include <sys/fanotify.h> #include <unistd.h> - +\& /* Read all available fanotify events from the file descriptor \[aq]fd\[aq]. */ - +\& static void handle_events(int fd) { @@ -1059,65 +1059,65 @@ handle_events(int fd) ssize_t path_len; char procfd_path[PATH_MAX]; struct fanotify_response response; - +\& /* Loop while events can be read from fanotify file descriptor. */ - +\& for (;;) { - +\& /* Read some events. */ - +\& len = read(fd, buf, sizeof(buf)); if (len == \-1 && errno != EAGAIN) { perror("read"); exit(EXIT_FAILURE); } - +\& /* Check if end of available data reached. */ - +\& if (len <= 0) break; - +\& /* Point to the first event in the buffer. */ - +\& metadata = buf; - +\& /* Loop over all events in the buffer. */ - +\& while (FAN_EVENT_OK(metadata, len)) { - +\& /* Check that run\-time and compile\-time structures match. */ - +\& if (metadata\->vers != FANOTIFY_METADATA_VERSION) { fprintf(stderr, "Mismatch of fanotify metadata version.\en"); exit(EXIT_FAILURE); } - +\& /* metadata\->fd contains either FAN_NOFD, indicating a queue overflow, or a file descriptor (a nonnegative integer). Here, we simply ignore queue overflow. */ - +\& if (metadata\->fd >= 0) { - +\& /* Handle open permission event. */ - +\& if (metadata\->mask & FAN_OPEN_PERM) { printf("FAN_OPEN_PERM: "); - +\& /* Allow file to be opened. */ - +\& response.fd = metadata\->fd; response.response = FAN_ALLOW; write(fd, &response, sizeof(response)); } - +\& /* Handle closing of writable file event. */ - +\& if (metadata\->mask & FAN_CLOSE_WRITE) printf("FAN_CLOSE_WRITE: "); - +\& /* Retrieve and print pathname of the accessed file. */ - +\& snprintf(procfd_path, sizeof(procfd_path), "/proc/self/fd/%d", metadata\->fd); path_len = readlink(procfd_path, path, @@ -1126,22 +1126,22 @@ handle_events(int fd) perror("readlink"); exit(EXIT_FAILURE); } - +\& path[path_len] = \[aq]\e0\[aq]; printf("File %s\en", path); - +\& /* Close the file descriptor of the event. */ - +\& close(metadata\->fd); } - +\& /* Advance to next event. */ - +\& metadata = FAN_EVENT_NEXT(metadata, len); } } } - +\& int main(int argc, char *argv[]) { @@ -1149,80 +1149,80 @@ main(int argc, char *argv[]) int fd, poll_num; nfds_t nfds; struct pollfd fds[2]; - +\& /* Check mount point is supplied. */ - +\& if (argc != 2) { fprintf(stderr, "Usage: %s MOUNT\en", argv[0]); exit(EXIT_FAILURE); } - +\& printf("Press enter key to terminate.\en"); - +\& /* Create the file descriptor for accessing the fanotify API. */ - +\& fd = fanotify_init(FAN_CLOEXEC | FAN_CLASS_CONTENT | FAN_NONBLOCK, O_RDONLY | O_LARGEFILE); if (fd == \-1) { perror("fanotify_init"); exit(EXIT_FAILURE); } - +\& /* Mark the mount for: \- permission events before opening files \- notification events after closing a write\-enabled file descriptor. */ - +\& if (fanotify_mark(fd, FAN_MARK_ADD | FAN_MARK_MOUNT, FAN_OPEN_PERM | FAN_CLOSE_WRITE, AT_FDCWD, argv[1]) == \-1) { perror("fanotify_mark"); exit(EXIT_FAILURE); } - +\& /* Prepare for polling. */ - +\& nfds = 2; - +\& fds[0].fd = STDIN_FILENO; /* Console input */ fds[0].events = POLLIN; - +\& fds[1].fd = fd; /* Fanotify input */ fds[1].events = POLLIN; - +\& /* This is the loop to wait for incoming events. */ - +\& printf("Listening for events.\en"); - +\& while (1) { poll_num = poll(fds, nfds, \-1); if (poll_num == \-1) { if (errno == EINTR) /* Interrupted by a signal */ continue; /* Restart poll() */ - +\& perror("poll"); /* Unexpected error */ exit(EXIT_FAILURE); } - +\& if (poll_num > 0) { if (fds[0].revents & POLLIN) { - +\& /* Console input is available: empty stdin and quit. */ - +\& while (read(STDIN_FILENO, &buf, 1) > 0 && buf != \[aq]\en\[aq]) continue; break; } - +\& if (fds[1].revents & POLLIN) { - +\& /* Fanotify events are available. */ - +\& handle_events(fd); } } } - +\& printf("Listening for events stopped.\en"); exit(EXIT_SUCCESS); } @@ -1263,7 +1263,7 @@ FAN_CREATE (file created): Directory /home/user has been modified. Entry \[aq]testfile.txt\[aq] is not a subdirectory. All events processed successfully. Program exiting. - +\& $ \fBtouch /home/user/testfile.txt\fP # In another terminal .EE .in @@ -1286,7 +1286,7 @@ FAN_CREATE | FAN_ONDIR (subdirectory created): Directory /home/user has been modified. Entry \[aq]testdir\[aq] is a subdirectory. All events processed successfully. Program exiting. - +\& $ \fBmkdir \-p /home/user/testdir\fP # In another terminal .EE .in @@ -1303,9 +1303,9 @@ $ \fBmkdir \-p /home/user/testdir\fP # In another terminal #include <sys/stat.h> #include <sys/fanotify.h> #include <unistd.h> - +\& #define BUF_SIZE 256 - +\& int main(int argc, char *argv[]) { @@ -1319,31 +1319,30 @@ main(int argc, char *argv[]) struct fanotify_event_info_fid *fid; const char *file_name; struct stat sb; - +\& if (argc != 2) { fprintf(stderr, "Invalid number of command line arguments.\en"); exit(EXIT_FAILURE); } - +\& mount_fd = open(argv[1], O_DIRECTORY | O_RDONLY); if (mount_fd == \-1) { perror(argv[1]); exit(EXIT_FAILURE); } - - +\& /* Create an fanotify file descriptor with FAN_REPORT_DFID_NAME as a flag so that program can receive fid events with directory entry name. */ - +\& fd = fanotify_init(FAN_CLASS_NOTIF | FAN_REPORT_DFID_NAME, 0); if (fd == \-1) { perror("fanotify_init"); exit(EXIT_FAILURE); } - +\& /* Place a mark on the filesystem object supplied in argv[1]. */ - +\& ret = fanotify_mark(fd, FAN_MARK_ADD | FAN_MARK_ONLYDIR, FAN_CREATE | FAN_ONDIR, AT_FDCWD, argv[1]); @@ -1351,27 +1350,27 @@ main(int argc, char *argv[]) perror("fanotify_mark"); exit(EXIT_FAILURE); } - +\& printf("Listening for events.\en"); - +\& /* Read events from the event queue into a buffer. */ - +\& len = read(fd, events_buf, sizeof(events_buf)); if (len == \-1 && errno != EAGAIN) { perror("read"); exit(EXIT_FAILURE); } - +\& /* Process all events within the buffer. */ - +\& for (metadata = (struct fanotify_event_metadata *) events_buf; FAN_EVENT_OK(metadata, len); metadata = FAN_EVENT_NEXT(metadata, len)) { fid = (struct fanotify_event_info_fid *) (metadata + 1); file_handle = (struct file_handle *) fid\->handle; - +\& /* Ensure that the event info is of the correct type. */ - +\& if (fid\->hdr.info_type == FAN_EVENT_INFO_TYPE_FID || fid\->hdr.info_type == FAN_EVENT_INFO_TYPE_DFID) { file_name = NULL; @@ -1382,13 +1381,13 @@ main(int argc, char *argv[]) fprintf(stderr, "Received unexpected event info type.\en"); exit(EXIT_FAILURE); } - +\& if (metadata\->mask == FAN_CREATE) printf("FAN_CREATE (file created):\en"); - +\& if (metadata\->mask == (FAN_CREATE | FAN_ONDIR)) printf("FAN_CREATE | FAN_ONDIR (subdirectory created):\en"); - +\& /* metadata\->fd is set to FAN_NOFD when the group identifies objects by file handles. To obtain a file descriptor for the file object corresponding to an event you can use the @@ -1397,7 +1396,7 @@ main(int argc, char *argv[]) open_by_handle_at(2) system call. A check for ESTALE is done to accommodate for the situation where the file handle for the object was deleted prior to this system call. */ - +\& event_fd = open_by_handle_at(mount_fd, file_handle, O_RDONLY); if (event_fd == \-1) { if (errno == ESTALE) { @@ -1409,21 +1408,21 @@ main(int argc, char *argv[]) exit(EXIT_FAILURE); } } - +\& snprintf(procfd_path, sizeof(procfd_path), "/proc/self/fd/%d", event_fd); - +\& /* Retrieve and print the path of the modified dentry. */ - +\& path_len = readlink(procfd_path, path, sizeof(path) \- 1); if (path_len == \-1) { perror("readlink"); exit(EXIT_FAILURE); } - +\& path[path_len] = \[aq]\e0\[aq]; printf("\etDirectory \[aq]%s\[aq] has been modified.\en", path); - +\& if (file_name) { ret = fstatat(event_fd, file_name, &sb, 0); if (ret == \-1) { @@ -1439,12 +1438,12 @@ main(int argc, char *argv[]) file_name); } } - +\& /* Close associated file descriptor for this event. */ - +\& close(event_fd); } - +\& printf("All events processed successfully. Program exiting.\en"); exit(EXIT_SUCCESS); } |