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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193// SPDX-License-Identifier: GPL-2.0/* Use watch_queue API to watch for notifications. * * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */
#define _GNU_SOURCE#include <stdbool.h>#include <stdarg.h>#include <stdio.h>#include <stdlib.h>#include <string.h>#include <signal.h>#include <unistd.h>#include <errno.h>#include <sys/ioctl.h>#include <limits.h>
// Work around glibc header silliness#undef AT_RENAME_NOREPLACE#undef AT_RENAME_EXCHANGE#undef AT_RENAME_WHITEOUT
#include <linux/watch_queue.h>#include <linux/unistd.h>#include <linux/keyctl.h>
#ifndef KEYCTL_WATCH_KEY#define KEYCTL_WATCH_KEY -1#endif#ifndef __NR_keyctl#define __NR_keyctl -1#endif
#define BUF_SIZE 256
static long keyctl_watch_key(int key, int watch_fd, int watch_id){ return syscall(__NR_keyctl, KEYCTL_WATCH_KEY, key, watch_fd, watch_id);}
static const char *key_subtypes[256] = { [NOTIFY_KEY_INSTANTIATED] = "instantiated", [NOTIFY_KEY_UPDATED] = "updated", [NOTIFY_KEY_LINKED] = "linked", [NOTIFY_KEY_UNLINKED] = "unlinked", [NOTIFY_KEY_CLEARED] = "cleared", [NOTIFY_KEY_REVOKED] = "revoked", [NOTIFY_KEY_INVALIDATED] = "invalidated", [NOTIFY_KEY_SETATTR] = "setattr",};
static void saw_key_change(struct watch_notification *n, size_t len){ struct key_notification *k = (struct key_notification *)n;
if (len != sizeof(struct key_notification)) { fprintf(stderr, "Incorrect key message length\n"); return; }
printf("KEY %08x change=%u[%s] aux=%u\n", k->key_id, n->subtype, key_subtypes[n->subtype], k->aux);}
/* * Consume and display events. */static void consumer(int fd){ unsigned char buffer[433], *p, *end; union { struct watch_notification n; unsigned char buf1[128]; } n; ssize_t buf_len;
for (;;) { buf_len = read(fd, buffer, sizeof(buffer)); if (buf_len == -1) { perror("read"); exit(1); }
if (buf_len == 0) { printf("-- END --\n"); return; }
if (buf_len > sizeof(buffer)) { fprintf(stderr, "Read buffer overrun: %zd\n", buf_len); return; }
printf("read() = %zd\n", buf_len);
p = buffer; end = buffer + buf_len; while (p < end) { size_t largest, len;
largest = end - p; if (largest > 128) largest = 128; if (largest < sizeof(struct watch_notification)) { fprintf(stderr, "Short message header: %zu\n", largest); return; } memcpy(&n, p, largest);
printf("NOTIFY[%03zx]: ty=%06x sy=%02x i=%08x\n", p - buffer, n.n.type, n.n.subtype, n.n.info);
len = n.n.info & WATCH_INFO_LENGTH; if (len < sizeof(n.n) || len > largest) { fprintf(stderr, "Bad message length: %zu/%zu\n", len, largest); exit(1); }
switch (n.n.type) { case WATCH_TYPE_META: switch (n.n.subtype) { case WATCH_META_REMOVAL_NOTIFICATION: printf("REMOVAL of watchpoint %08x\n", (n.n.info & WATCH_INFO_ID) >> WATCH_INFO_ID__SHIFT); break; case WATCH_META_LOSS_NOTIFICATION: printf("-- LOSS --\n"); break; default: printf("other meta record\n"); break; } break; case WATCH_TYPE_KEY_NOTIFY: saw_key_change(&n.n, len); break; default: printf("other type\n"); break; }
p += len; } }}
static struct watch_notification_filter filter = { .nr_filters = 1, .filters = { [0] = { .type = WATCH_TYPE_KEY_NOTIFY, .subtype_filter[0] = UINT_MAX, }, },};
int main(int argc, char **argv){ int pipefd[2], fd;
if (pipe2(pipefd, O_NOTIFICATION_PIPE) == -1) { perror("pipe2"); exit(1); } fd = pipefd[0];
if (ioctl(fd, IOC_WATCH_QUEUE_SET_SIZE, BUF_SIZE) == -1) { perror("watch_queue(size)"); exit(1); }
if (ioctl(fd, IOC_WATCH_QUEUE_SET_FILTER, &filter) == -1) { perror("watch_queue(filter)"); exit(1); }
if (keyctl_watch_key(KEY_SPEC_SESSION_KEYRING, fd, 0x01) == -1) { perror("keyctl"); exit(1); }
if (keyctl_watch_key(KEY_SPEC_USER_KEYRING, fd, 0x02) == -1) { perror("keyctl"); exit(1); }
consumer(fd); exit(0);}