1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright 2021, Collabora Ltd. 4 */ 5 6 #define _GNU_SOURCE 7 #include <errno.h> 8 #include <err.h> 9 #include <stdlib.h> 10 #include <stdio.h> 11 #include <fcntl.h> 12 #include <sys/fanotify.h> 13 #include <sys/types.h> 14 #include <unistd.h> 15 16 #ifndef FAN_FS_ERROR 17 #define FAN_FS_ERROR 0x00008000 18 #define FAN_EVENT_INFO_TYPE_ERROR 5 19 20 struct fanotify_event_info_error { 21 struct fanotify_event_info_header hdr; 22 __s32 error; 23 __u32 error_count; 24 }; 25 #endif 26 27 #ifndef FILEID_INO32_GEN 28 #define FILEID_INO32_GEN 1 29 #endif 30 31 #ifndef FILEID_INVALID 32 #define FILEID_INVALID 0xff 33 #endif 34 35 static void print_fh(struct file_handle *fh) 36 { 37 int i; 38 uint32_t *h = (uint32_t *) fh->f_handle; 39 40 printf("\tfh: "); 41 for (i = 0; i < fh->handle_bytes; i++) 42 printf("%hhx", fh->f_handle[i]); 43 printf("\n"); 44 45 printf("\tdecoded fh: "); 46 if (fh->handle_type == FILEID_INO32_GEN) 47 printf("inode=%u gen=%u\n", h[0], h[1]); 48 else if (fh->handle_type == FILEID_INVALID && !fh->handle_bytes) 49 printf("Type %d (Superblock error)\n", fh->handle_type); 50 else 51 printf("Type %d (Unknown)\n", fh->handle_type); 52 53 } 54 55 static void handle_notifications(char *buffer, int len) 56 { 57 struct fanotify_event_metadata *event = 58 (struct fanotify_event_metadata *) buffer; 59 struct fanotify_event_info_header *info; 60 struct fanotify_event_info_error *err; 61 struct fanotify_event_info_fid *fid; 62 int off; 63 64 for (; FAN_EVENT_OK(event, len); event = FAN_EVENT_NEXT(event, len)) { 65 66 if (event->mask != FAN_FS_ERROR) { 67 printf("unexpected FAN MARK: %llx\n", 68 (unsigned long long)event->mask); 69 goto next_event; 70 } 71 72 if (event->fd != FAN_NOFD) { 73 printf("Unexpected fd (!= FAN_NOFD)\n"); 74 goto next_event; 75 } 76 77 printf("FAN_FS_ERROR (len=%d)\n", event->event_len); 78 79 for (off = sizeof(*event) ; off < event->event_len; 80 off += info->len) { 81 info = (struct fanotify_event_info_header *) 82 ((char *) event + off); 83 84 switch (info->info_type) { 85 case FAN_EVENT_INFO_TYPE_ERROR: 86 err = (struct fanotify_event_info_error *) info; 87 88 printf("\tGeneric Error Record: len=%d\n", 89 err->hdr.len); 90 printf("\terror: %d\n", err->error); 91 printf("\terror_count: %d\n", err->error_count); 92 break; 93 94 case FAN_EVENT_INFO_TYPE_FID: 95 fid = (struct fanotify_event_info_fid *) info; 96 97 printf("\tfsid: %x%x\n", 98 fid->fsid.val[0], fid->fsid.val[1]); 99 print_fh((struct file_handle *) &fid->handle); 100 break; 101 102 default: 103 printf("\tUnknown info type=%d len=%d:\n", 104 info->info_type, info->len); 105 } 106 } 107 next_event: 108 printf("---\n\n"); 109 } 110 } 111 112 int main(int argc, char **argv) 113 { 114 int fd; 115 116 char buffer[BUFSIZ]; 117 118 if (argc < 2) { 119 printf("Missing path argument\n"); 120 return 1; 121 } 122 123 fd = fanotify_init(FAN_CLASS_NOTIF|FAN_REPORT_FID, O_RDONLY); 124 if (fd < 0) 125 errx(1, "fanotify_init"); 126 127 if (fanotify_mark(fd, FAN_MARK_ADD|FAN_MARK_FILESYSTEM, 128 FAN_FS_ERROR, AT_FDCWD, argv[1])) { 129 errx(1, "fanotify_mark"); 130 } 131 132 while (1) { 133 int n = read(fd, buffer, BUFSIZ); 134 135 if (n < 0) 136 errx(1, "read"); 137 138 handle_notifications(buffer, n); 139 } 140 141 return 0; 142 } 143