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 #ifndef __GLIBC__ 16 #include <asm-generic/int-ll64.h> 17 #endif 18 19 #ifndef FAN_FS_ERROR 20 #define FAN_FS_ERROR 0x00008000 21 #define FAN_EVENT_INFO_TYPE_ERROR 5 22 23 struct fanotify_event_info_error { 24 struct fanotify_event_info_header hdr; 25 __s32 error; 26 __u32 error_count; 27 }; 28 #endif 29 30 #ifndef FILEID_INO32_GEN 31 #define FILEID_INO32_GEN 1 32 #endif 33 34 #ifndef FILEID_INVALID 35 #define FILEID_INVALID 0xff 36 #endif 37 38 static void print_fh(struct file_handle *fh) 39 { 40 int i; 41 uint32_t *h = (uint32_t *) fh->f_handle; 42 43 printf("\tfh: "); 44 for (i = 0; i < fh->handle_bytes; i++) 45 printf("%hhx", fh->f_handle[i]); 46 printf("\n"); 47 48 printf("\tdecoded fh: "); 49 if (fh->handle_type == FILEID_INO32_GEN) 50 printf("inode=%u gen=%u\n", h[0], h[1]); 51 else if (fh->handle_type == FILEID_INVALID && !fh->handle_bytes) 52 printf("Type %d (Superblock error)\n", fh->handle_type); 53 else 54 printf("Type %d (Unknown)\n", fh->handle_type); 55 56 } 57 58 static void handle_notifications(char *buffer, int len) 59 { 60 struct fanotify_event_metadata *event = 61 (struct fanotify_event_metadata *) buffer; 62 struct fanotify_event_info_header *info; 63 struct fanotify_event_info_error *err; 64 struct fanotify_event_info_fid *fid; 65 int off; 66 67 for (; FAN_EVENT_OK(event, len); event = FAN_EVENT_NEXT(event, len)) { 68 69 if (event->mask != FAN_FS_ERROR) { 70 printf("unexpected FAN MARK: %llx\n", 71 (unsigned long long)event->mask); 72 goto next_event; 73 } 74 75 if (event->fd != FAN_NOFD) { 76 printf("Unexpected fd (!= FAN_NOFD)\n"); 77 goto next_event; 78 } 79 80 printf("FAN_FS_ERROR (len=%d)\n", event->event_len); 81 82 for (off = sizeof(*event) ; off < event->event_len; 83 off += info->len) { 84 info = (struct fanotify_event_info_header *) 85 ((char *) event + off); 86 87 switch (info->info_type) { 88 case FAN_EVENT_INFO_TYPE_ERROR: 89 err = (struct fanotify_event_info_error *) info; 90 91 printf("\tGeneric Error Record: len=%d\n", 92 err->hdr.len); 93 printf("\terror: %d\n", err->error); 94 printf("\terror_count: %d\n", err->error_count); 95 break; 96 97 case FAN_EVENT_INFO_TYPE_FID: 98 fid = (struct fanotify_event_info_fid *) info; 99 100 printf("\tfsid: %x%x\n", 101 #if defined(__GLIBC__) 102 fid->fsid.val[0], fid->fsid.val[1]); 103 #else 104 fid->fsid.__val[0], fid->fsid.__val[1]); 105 #endif 106 print_fh((struct file_handle *) &fid->handle); 107 break; 108 109 default: 110 printf("\tUnknown info type=%d len=%d:\n", 111 info->info_type, info->len); 112 } 113 } 114 next_event: 115 printf("---\n\n"); 116 } 117 } 118 119 int main(int argc, char **argv) 120 { 121 int fd; 122 123 char buffer[BUFSIZ]; 124 125 if (argc < 2) { 126 printf("Missing path argument\n"); 127 return 1; 128 } 129 130 fd = fanotify_init(FAN_CLASS_NOTIF|FAN_REPORT_FID, O_RDONLY); 131 if (fd < 0) 132 errx(1, "fanotify_init"); 133 134 if (fanotify_mark(fd, FAN_MARK_ADD|FAN_MARK_FILESYSTEM, 135 FAN_FS_ERROR, AT_FDCWD, argv[1])) { 136 errx(1, "fanotify_mark"); 137 } 138 139 while (1) { 140 int n = read(fd, buffer, BUFSIZ); 141 142 if (n < 0) 143 errx(1, "read"); 144 145 handle_notifications(buffer, n); 146 } 147 148 return 0; 149 } 150