/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include "fd-util.h"

#include "inotify-util.h"

#include "log.h"

#include "memory-util.h"

bool inotify_event_next(

                union inotify_event_buffer *buffer,

                size_t size,

                struct inotify_event **iterator,

                int log_level) {

        struct inotify_event *e;

        size_t offset = 0;

        assert(buffer);

        assert(iterator);

        if (*iterator) {

                assert((uint8_t*) *iterator >= buffer->raw);

                offset = (uint8_t*) *iterator - buffer->raw;

                offset += offsetof(struct inotify_event, name) + (*iterator)->len;

        }

        if (size == offset)

                return false; /* reached end of list */

        if (size < offset ||

            size - offset < offsetof(struct inotify_event, name)) {

                log_full(log_level, "Received invalid inotify event, ignoring.");

                return false;

        }

        e = CAST_ALIGN_PTR(struct inotify_event, buffer->raw + offset);

        if (size - offset - offsetof(struct inotify_event, name) < e->len) {

                log_full(log_level, "Received invalid inotify event, ignoring.");

                return false;

        }

        *iterator = e;

        return true;

}

int inotify_add_watch_fd(int fd, int what, uint32_t mask) {

        int wd;

        assert(fd >= 0);

        assert(what >= 0);

        /* This is like inotify_add_watch(), except that the file to watch is not referenced by a path, but by an fd */

        wd = inotify_add_watch(fd, FORMAT_PROC_FD_PATH(what), mask);

        if (wd < 0) {

                if (errno != ENOENT)

                        return -errno;

                return proc_fd_enoent_errno();

        }

        return wd;

}

int inotify_add_watch_and_warn(int fd, const char *pathname, uint32_t mask) {

        int wd;

        wd = inotify_add_watch(fd, pathname, mask);

        if (wd < 0) {

                if (errno == ENOSPC)

                        return log_error_errno(errno, "Failed to add a watch for %s: inotify watch limit reached", pathname);

                return log_error_errno(errno, "Failed to add a watch for %s: %m", pathname);

        }

        return wd;

}