src/journal/journal-gatewayd.c

	journal-gatewayd.c revision a860325e7ed7ea2bd688b2f002021123a05af084
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer/***
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  This file is part of systemd.
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  Copyright 2012 Lennart Poettering
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  systemd is free software; you can redistribute it and/or modify it
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  under the terms of the GNU Lesser General Public License as published by
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  the Free Software Foundation; either version 2.1 of the License, or
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  (at your option) any later version.
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  systemd is distributed in the hope that it will be useful, but
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  WITHOUT ANY WARRANTY; without even the implied warranty of
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  Lesser General Public License for more details.
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  You should have received a copy of the GNU Lesser General Public License
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer  along with systemd; If not, see <http://www.gnu.org/licenses/>.
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer***/
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
32d965851d8cbb39f8ee0eeaf76a89e8f5fc174fLennart Poettering#include <stdlib.h>
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include <string.h>
32d965851d8cbb39f8ee0eeaf76a89e8f5fc174fLennart Poettering#include <unistd.h>
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include <fcntl.h>
32d965851d8cbb39f8ee0eeaf76a89e8f5fc174fLennart Poettering#include <getopt.h>
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include <microhttpd.h>
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include "log.h"
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include "util.h"
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include "sd-journal.h"
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include "sd-daemon.h"
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include "logs-show.h"
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include "microhttpd-util.h"
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include "virt.h"
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include "build.h"
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#include "fileio.h"
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyertypedef struct RequestMeta {
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        sd_journal *journal;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        OutputMode mode;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        char *cursor;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        int64_t n_skip;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        uint64_t n_entries;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        bool n_entries_set;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        FILE *tmp;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        uint64_t delta, size;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        int argument_parse_error;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        bool follow;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        bool discrete;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        uint64_t n_fields;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        bool n_fields_set;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer} RequestMeta;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyerstatic const char* const mime_types[_OUTPUT_MODE_MAX] = {
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        [OUTPUT_SHORT] = "text/plain",
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        [OUTPUT_JSON] = "application/json",
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        [OUTPUT_JSON_SSE] = "text/event-stream",
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        [OUTPUT_EXPORT] = "application/vnd.fdo.journal",
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer};
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyerstatic RequestMeta *request_meta(void **connection_cls) {
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        RequestMeta *m;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        if (*connection_cls)
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                return *connection_cls;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        m = new0(RequestMeta, 1);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        if (!m)
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                return NULL;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        *connection_cls = m;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        return m;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer}
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyerstatic void request_meta_free(
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                void *cls,
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                struct MHD_Connection *connection,
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                void **connection_cls,
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                enum MHD_RequestTerminationCode toe) {
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        RequestMeta *m = *connection_cls;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        if (!m)
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                return;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        if (m->journal)
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                sd_journal_close(m->journal);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        if (m->tmp)
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                fclose(m->tmp);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        free(m->cursor);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        free(m);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer}
32d965851d8cbb39f8ee0eeaf76a89e8f5fc174fLennart Poettering
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyerstatic int open_journal(RequestMeta *m) {
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        assert(m);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        if (m->journal)
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                return 0;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        return sd_journal_open(&m->journal, SD_JOURNAL_LOCAL_ONLY|SD_JOURNAL_SYSTEM_ONLY);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer}
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyerstatic int respond_oom_internal(struct MHD_Connection *connection) {
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        struct MHD_Response *response;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        const char m[] = "Out of memory.\n";
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        int ret;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        assert(connection);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        response = MHD_create_response_from_buffer(sizeof(m)-1, (char*) m, MHD_RESPMEM_PERSISTENT);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        if (!response)
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                return MHD_NO;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        MHD_add_response_header(response, "Content-Type", "text/plain");
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        ret = MHD_queue_response(connection, MHD_HTTP_SERVICE_UNAVAILABLE, response);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        MHD_destroy_response(response);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        return ret;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer}
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer#define respond_oom(connection) log_oom(), respond_oom_internal(connection)
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyerstatic int respond_error(
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                struct MHD_Connection *connection,
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                unsigned code,
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                const char *format, ...) {
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        struct MHD_Response *response;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        char *m;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        int r;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        va_list ap;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        assert(connection);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        assert(format);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        va_start(ap, format);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        r = vasprintf(&m, format, ap);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        va_end(ap);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        if (r < 0)
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                return respond_oom(connection);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        response = MHD_create_response_from_buffer(strlen(m), m, MHD_RESPMEM_MUST_FREE);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        if (!response) {
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                free(m);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                return respond_oom(connection);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        }
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        MHD_add_response_header(response, "Content-Type", "text/plain");
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        r = MHD_queue_response(connection, code, response);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        MHD_destroy_response(response);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        return r;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer}
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyerstatic ssize_t request_reader_entries(
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                void *cls,
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                uint64_t pos,
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                char *buf,
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                size_t max) {
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        RequestMeta *m = cls;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        int r;
32d965851d8cbb39f8ee0eeaf76a89e8f5fc174fLennart Poettering        size_t n, k;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        assert(m);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        assert(buf);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        assert(max > 0);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        assert(pos >= m->delta);
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        pos -= m->delta;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer        while (pos >= m->size) {
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                off_t sz;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                /* End of this entry, so let's serialize the next
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                 * one */
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                if (m->n_entries_set &&
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                    m->n_entries <= 0)
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer                        return MHD_CONTENT_READER_END_OF_STREAM;
898720b7e9cf3bdf7a93e435cbed5dd6942ecf9bHarald Hoyer
                if (m->n_skip < 0)
                        r = sd_journal_previous_skip(m->journal, (uint64_t) -m->n_skip + 1);
                else if (m->n_skip > 0)
                        r = sd_journal_next_skip(m->journal, (uint64_t) m->n_skip + 1);
                else
                        r = sd_journal_next(m->journal);

                if (r < 0) {
                        log_error("Failed to advance journal pointer: %s", strerror(-r));
                        return MHD_CONTENT_READER_END_WITH_ERROR;
                } else if (r == 0) {

                        if (m->follow) {
                                r = sd_journal_wait(m->journal, (uint64_t) -1);
                                if (r < 0) {
                                        log_error("Couldn't wait for journal event: %s", strerror(-r));
                                        return MHD_CONTENT_READER_END_WITH_ERROR;
                                }

                                continue;
                        }

                        return MHD_CONTENT_READER_END_OF_STREAM;
                }

                if (m->discrete) {
                        assert(m->cursor);

                        r = sd_journal_test_cursor(m->journal, m->cursor);
                        if (r < 0) {
                                log_error("Failed to test cursor: %s", strerror(-r));
                                return MHD_CONTENT_READER_END_WITH_ERROR;
                        }

                        if (r == 0)
                                return MHD_CONTENT_READER_END_OF_STREAM;
                }

                pos -= m->size;
                m->delta += m->size;

                if (m->n_entries_set)
                        m->n_entries -= 1;

                m->n_skip = 0;

                if (m->tmp)
                        rewind(m->tmp);
                else {
                        m->tmp = tmpfile();
                        if (!m->tmp) {
                                log_error("Failed to create temporary file: %m");
                                return MHD_CONTENT_READER_END_WITH_ERROR;
                        }
                }

                r = output_journal(m->tmp, m->journal, m->mode, 0, OUTPUT_FULL_WIDTH);
                if (r < 0) {
                        log_error("Failed to serialize item: %s", strerror(-r));
                        return MHD_CONTENT_READER_END_WITH_ERROR;
                }

                sz = ftello(m->tmp);
                if (sz == (off_t) -1) {
                        log_error("Failed to retrieve file position: %m");
                        return MHD_CONTENT_READER_END_WITH_ERROR;
                }

                m->size = (uint64_t) sz;
        }

        if (fseeko(m->tmp, pos, SEEK_SET) < 0) {
                log_error("Failed to seek to position: %m");
                return MHD_CONTENT_READER_END_WITH_ERROR;
        }

        n = m->size - pos;
        if (n > max)
                n = max;

        errno = 0;
        k = fread(buf, 1, n, m->tmp);
        if (k != n) {
                log_error("Failed to read from file: %s", errno ? strerror(errno) : "Premature EOF");
                return MHD_CONTENT_READER_END_WITH_ERROR;
        }

        return (ssize_t) k;
}

static int request_parse_accept(
                RequestMeta *m,
                struct MHD_Connection *connection) {

        const char *header;

        assert(m);
        assert(connection);

        header = MHD_lookup_connection_value(connection, MHD_HEADER_KIND, "Accept");
        if (!header)
                return 0;

        if (streq(header, mime_types[OUTPUT_JSON]))
                m->mode = OUTPUT_JSON;
        else if (streq(header, mime_types[OUTPUT_JSON_SSE]))
                m->mode = OUTPUT_JSON_SSE;
        else if (streq(header, mime_types[OUTPUT_EXPORT]))
                m->mode = OUTPUT_EXPORT;
        else
                m->mode = OUTPUT_SHORT;

        return 0;
}

static int request_parse_range(
                RequestMeta *m,
                struct MHD_Connection *connection) {

        const char *range, *colon, *colon2;
        int r;

        assert(m);
        assert(connection);

        range = MHD_lookup_connection_value(connection, MHD_HEADER_KIND, "Range");
        if (!range)
                return 0;

        if (!startswith(range, "entries="))
                return 0;

        range += 8;
        range += strspn(range, WHITESPACE);

        colon = strchr(range, ':');
        if (!colon)
                m->cursor = strdup(range);
        else {
                const char *p;

                colon2 = strchr(colon + 1, ':');
                if (colon2) {
                        char _cleanup_free_ *t;

                        t = strndup(colon + 1, colon2 - colon - 1);
                        if (!t)
                                return -ENOMEM;

                        r = safe_atoi64(t, &m->n_skip);
                        if (r < 0)
                                return r;
                }

                p = (colon2 ? colon2 : colon) + 1;
                if (*p) {
                        r = safe_atou64(p, &m->n_entries);
                        if (r < 0)
                                return r;

                        if (m->n_entries <= 0)
                                return -EINVAL;

                        m->n_entries_set = true;
                }

                m->cursor = strndup(range, colon - range);
        }

        if (!m->cursor)
                return -ENOMEM;

        m->cursor[strcspn(m->cursor, WHITESPACE)] = 0;
        if (isempty(m->cursor)) {
                free(m->cursor);
                m->cursor = NULL;
        }

        return 0;
}

static int request_parse_arguments_iterator(
                void *cls,
                enum MHD_ValueKind kind,
                const char *key,
                const char *value) {

        RequestMeta *m = cls;
        _cleanup_free_ char *p = NULL;
        int r;

        assert(m);

        if (isempty(key)) {
                m->argument_parse_error = -EINVAL;
                return MHD_NO;
        }

        if (streq(key, "follow")) {
                if (isempty(value)) {
                        m->follow = true;
                        return MHD_YES;
                }

                r = parse_boolean(value);
                if (r < 0) {
                        m->argument_parse_error = r;
                        return MHD_NO;
                }

                m->follow = r;
                return MHD_YES;
        }

        if (streq(key, "discrete")) {
                if (isempty(value)) {
                        m->discrete = true;
                        return MHD_YES;
                }

                r = parse_boolean(value);
                if (r < 0) {
                        m->argument_parse_error = r;
                        return MHD_NO;
                }

                m->discrete = r;
                return MHD_YES;
        }

        if (streq(key, "boot")) {
                if (isempty(value))
                        r = true;
                else {
                        r = parse_boolean(value);
                        if (r < 0) {
                                m->argument_parse_error = r;
                                return MHD_NO;
                        }
                }

                if (r) {
                        char match[9 + 32 + 1] = "_BOOT_ID=";
                        sd_id128_t bid;

                        r = sd_id128_get_boot(&bid);
                        if (r < 0) {
                                log_error("Failed to get boot ID: %s", strerror(-r));
                                return MHD_NO;
                        }

                        sd_id128_to_string(bid, match + 9);
                        r = sd_journal_add_match(m->journal, match, sizeof(match)-1);
                        if (r < 0) {
                                m->argument_parse_error = r;
                                return MHD_NO;
                        }
                }

                return MHD_YES;
        }

        p = strjoin(key, "=", strempty(value), NULL);
        if (!p) {
                m->argument_parse_error = log_oom();
                return MHD_NO;
        }

        r = sd_journal_add_match(m->journal, p, 0);
        if (r < 0) {
                m->argument_parse_error = r;
                return MHD_NO;
        }

        return MHD_YES;
}

static int request_parse_arguments(
                RequestMeta *m,
                struct MHD_Connection *connection) {

        assert(m);
        assert(connection);

        m->argument_parse_error = 0;
        MHD_get_connection_values(connection, MHD_GET_ARGUMENT_KIND, request_parse_arguments_iterator, m);

        return m->argument_parse_error;
}

static int request_handler_entries(
                struct MHD_Connection *connection,
                void *connection_cls) {

        struct MHD_Response *response;
        RequestMeta *m = connection_cls;
        int r;

        assert(connection);
        assert(m);

        r = open_journal(m);
        if (r < 0)
                return respond_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR, "Failed to open journal: %s\n", strerror(-r));

        if (request_parse_accept(m, connection) < 0)
                return respond_error(connection, MHD_HTTP_BAD_REQUEST, "Failed to parse Accept header.\n");

        if (request_parse_range(m, connection) < 0)
                return respond_error(connection, MHD_HTTP_BAD_REQUEST, "Failed to parse Range header.\n");

        if (request_parse_arguments(m, connection) < 0)
                return respond_error(connection, MHD_HTTP_BAD_REQUEST, "Failed to parse URL arguments.\n");

        if (m->discrete) {
                if (!m->cursor)
                        return respond_error(connection, MHD_HTTP_BAD_REQUEST, "Discrete seeks require a cursor specification.\n");

                m->n_entries = 1;
                m->n_entries_set = true;
        }

        if (m->cursor)
                r = sd_journal_seek_cursor(m->journal, m->cursor);
        else if (m->n_skip >= 0)
                r = sd_journal_seek_head(m->journal);
        else if (m->n_skip < 0)
                r = sd_journal_seek_tail(m->journal);
        if (r < 0)
                return respond_error(connection, MHD_HTTP_BAD_REQUEST, "Failed to seek in journal.\n");

        response = MHD_create_response_from_callback(MHD_SIZE_UNKNOWN, 4*1024, request_reader_entries, m, NULL);
        if (!response)
                return respond_oom(connection);

        MHD_add_response_header(response, "Content-Type", mime_types[m->mode]);

        r = MHD_queue_response(connection, MHD_HTTP_OK, response);
        MHD_destroy_response(response);

        return r;
}

static int output_field(FILE *f, OutputMode m, const char *d, size_t l) {
        const char *eq;
        size_t j;

        eq = memchr(d, '=', l);
        if (!eq)
                return -EINVAL;

        j = l - (eq - d + 1);

        if (m == OUTPUT_JSON) {
                fprintf(f, "{ \"%.*s\" : ", (int) (eq - d), d);
                json_escape(f, eq+1, j, OUTPUT_FULL_WIDTH);
                fputs(" }\n", f);
        } else {
                fwrite(eq+1, 1, j, f);
                fputc('\n', f);
        }

        return 0;
}

static ssize_t request_reader_fields(
                void *cls,
                uint64_t pos,
                char *buf,
                size_t max) {

        RequestMeta *m = cls;
        int r;
        size_t n, k;

        assert(m);
        assert(buf);
        assert(max > 0);
        assert(pos >= m->delta);

        pos -= m->delta;

        while (pos >= m->size) {
                off_t sz;
                const void *d;
                size_t l;

                /* End of this field, so let's serialize the next
                 * one */

                if (m->n_fields_set &&
                    m->n_fields <= 0)
                        return MHD_CONTENT_READER_END_OF_STREAM;

                r = sd_journal_enumerate_unique(m->journal, &d, &l);
                if (r < 0) {
                        log_error("Failed to advance field index: %s", strerror(-r));
                        return MHD_CONTENT_READER_END_WITH_ERROR;
                } else if (r == 0)
                        return MHD_CONTENT_READER_END_OF_STREAM;

                pos -= m->size;
                m->delta += m->size;

                if (m->n_fields_set)
                        m->n_fields -= 1;

                if (m->tmp)
                        rewind(m->tmp);
                else {
                        m->tmp = tmpfile();
                        if (!m->tmp) {
                                log_error("Failed to create temporary file: %m");
                                return MHD_CONTENT_READER_END_WITH_ERROR;
                        }
                }

                r = output_field(m->tmp, m->mode, d, l);
                if (r < 0) {
                        log_error("Failed to serialize item: %s", strerror(-r));
                        return MHD_CONTENT_READER_END_WITH_ERROR;
                }

                sz = ftello(m->tmp);
                if (sz == (off_t) -1) {
                        log_error("Failed to retrieve file position: %m");
                        return MHD_CONTENT_READER_END_WITH_ERROR;
                }

                m->size = (uint64_t) sz;
        }

        if (fseeko(m->tmp, pos, SEEK_SET) < 0) {
                log_error("Failed to seek to position: %m");
                return MHD_CONTENT_READER_END_WITH_ERROR;
        }

        n = m->size - pos;
        if (n > max)
                n = max;

        errno = 0;
        k = fread(buf, 1, n, m->tmp);
        if (k != n) {
                log_error("Failed to read from file: %s", errno ? strerror(errno) : "Premature EOF");
                return MHD_CONTENT_READER_END_WITH_ERROR;
        }

        return (ssize_t) k;
}

static int request_handler_fields(
                struct MHD_Connection *connection,
                const char *field,
                void *connection_cls) {

        struct MHD_Response *response;
        RequestMeta *m = connection_cls;
        int r;

        assert(connection);
        assert(m);

        r = open_journal(m);
        if (r < 0)
                return respond_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR, "Failed to open journal: %s\n", strerror(-r));

        if (request_parse_accept(m, connection) < 0)
                return respond_error(connection, MHD_HTTP_BAD_REQUEST, "Failed to parse Accept header.\n");

        r = sd_journal_query_unique(m->journal, field);
        if (r < 0)
                return respond_error(connection, MHD_HTTP_BAD_REQUEST, "Failed to query unique fields.\n");

        response = MHD_create_response_from_callback(MHD_SIZE_UNKNOWN, 4*1024, request_reader_fields, m, NULL);
        if (!response)
                return respond_oom(connection);

        MHD_add_response_header(response, "Content-Type", mime_types[m->mode == OUTPUT_JSON ? OUTPUT_JSON : OUTPUT_SHORT]);

        r = MHD_queue_response(connection, MHD_HTTP_OK, response);
        MHD_destroy_response(response);

        return r;
}

static int request_handler_redirect(
                struct MHD_Connection *connection,
                const char *target) {

        char *page;
        struct MHD_Response *response;
        int ret;

        assert(connection);
        assert(target);

        if (asprintf(&page, "<html><body>Please continue to the <a href=\"%s\">journal browser</a>.</body></html>", target) < 0)
                return respond_oom(connection);

        response = MHD_create_response_from_buffer(strlen(page), page, MHD_RESPMEM_MUST_FREE);
        if (!response) {
                free(page);
                return respond_oom(connection);
        }

        MHD_add_response_header(response, "Content-Type", "text/html");
        MHD_add_response_header(response, "Location", target);

        ret = MHD_queue_response(connection, MHD_HTTP_MOVED_PERMANENTLY, response);
        MHD_destroy_response(response);

        return ret;
}

static int request_handler_file(
                struct MHD_Connection *connection,
                const char *path,
                const char *mime_type) {

        struct MHD_Response *response;
        int ret;
        _cleanup_close_ int fd = -1;
        struct stat st;

        assert(connection);
        assert(path);
        assert(mime_type);

        fd = open(path, O_RDONLY|O_CLOEXEC);
        if (fd < 0)
                return respond_error(connection, MHD_HTTP_NOT_FOUND, "Failed to open file %s: %m\n", path);

        if (fstat(fd, &st) < 0)
                return respond_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR, "Failed to stat file: %m\n");

        response = MHD_create_response_from_fd_at_offset(st.st_size, fd, 0);
        if (!response)
                return respond_oom(connection);

        fd = -1;

        MHD_add_response_header(response, "Content-Type", mime_type);

        ret = MHD_queue_response(connection, MHD_HTTP_OK, response);
        MHD_destroy_response(response);

        return ret;
}

static int request_handler_machine(
                struct MHD_Connection *connection,
                void *connection_cls) {

        struct MHD_Response *response;
        RequestMeta *m = connection_cls;
        int r;
        _cleanup_free_ char* hostname = NULL, *os_name = NULL;
        uint64_t cutoff_from, cutoff_to, usage;
        char *json;
        sd_id128_t mid, bid;
        const char *v = "bare";

        assert(connection);
        assert(m);

        r = open_journal(m);
        if (r < 0)
                return respond_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR, "Failed to open journal: %s\n", strerror(-r));

        r = sd_id128_get_machine(&mid);
        if (r < 0)
                return respond_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR, "Failed to determine machine ID: %s\n", strerror(-r));

        r = sd_id128_get_boot(&bid);
        if (r < 0)
                return respond_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR, "Failed to determine boot ID: %s\n", strerror(-r));

        hostname = gethostname_malloc();
        if (!hostname)
                return respond_oom(connection);

        r = sd_journal_get_usage(m->journal, &usage);
        if (r < 0)
                return respond_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR, "Failed to determine disk usage: %s\n", strerror(-r));

        r = sd_journal_get_cutoff_realtime_usec(m->journal, &cutoff_from, &cutoff_to);
        if (r < 0)
                return respond_error(connection, MHD_HTTP_INTERNAL_SERVER_ERROR, "Failed to determine disk usage: %s\n", strerror(-r));

        parse_env_file("/etc/os-release", NEWLINE, "PRETTY_NAME", &os_name, NULL);

        detect_virtualization(&v);

        r = asprintf(&json,
                     "{ \"machine_id\" : \"" SD_ID128_FORMAT_STR "\","
                     "\"boot_id\" : \"" SD_ID128_FORMAT_STR "\","
                     "\"hostname\" : \"%s\","
                     "\"os_pretty_name\" : \"%s\","
                     "\"virtualization\" : \"%s\","
                     "\"usage\" : \"%llu\","
                     "\"cutoff_from_realtime\" : \"%llu\","
                     "\"cutoff_to_realtime\" : \"%llu\" }\n",
                     SD_ID128_FORMAT_VAL(mid),
                     SD_ID128_FORMAT_VAL(bid),
                     hostname_cleanup(hostname),
                     os_name ? os_name : "Linux",
                     v,
                     (unsigned long long) usage,
                     (unsigned long long) cutoff_from,
                     (unsigned long long) cutoff_to);

        if (r < 0)
                return respond_oom(connection);

        response = MHD_create_response_from_buffer(strlen(json), json, MHD_RESPMEM_MUST_FREE);
        if (!response) {
                free(json);
                return respond_oom(connection);
        }

        MHD_add_response_header(response, "Content-Type", "application/json");
        r = MHD_queue_response(connection, MHD_HTTP_OK, response);
        MHD_destroy_response(response);

        return r;
}

static int request_handler(
                void *cls,
                struct MHD_Connection *connection,
                const char *url,
                const char *method,
                const char *version,
                const char *upload_data,
                size_t *upload_data_size,
                void **connection_cls) {

        assert(connection);
        assert(connection_cls);
        assert(url);
        assert(method);

        if (!streq(method, "GET"))
                return respond_error(connection, MHD_HTTP_METHOD_NOT_ACCEPTABLE,
                                     "Unsupported method.\n");


        if (!*connection_cls) {
                if (!request_meta(connection_cls))
                        return respond_oom(connection);
                return MHD_YES;
        }

        if (streq(url, "/"))
                return request_handler_redirect(connection, "/browse");

        if (streq(url, "/entries"))
                return request_handler_entries(connection, *connection_cls);

        if (startswith(url, "/fields/"))
                return request_handler_fields(connection, url + 8, *connection_cls);

        if (streq(url, "/browse"))
                return request_handler_file(connection, DOCUMENT_ROOT "/browse.html", "text/html");

        if (streq(url, "/machine"))
                return request_handler_machine(connection, *connection_cls);

        return respond_error(connection, MHD_HTTP_NOT_FOUND, "Not found.\n");
}

static int help(void) {

        printf("%s [OPTIONS...] ...\n\n"
               "HTTP server for journal events.\n\n"
               "  -h --help           Show this help\n"
               "     --version        Show package version\n"
               "     --cert=CERT.PEM  Specify server certificate in PEM format\n"
               "     --key=KEY.PEM    Specify server key in PEM format\n",
               program_invocation_short_name);

        return 0;
}

static char *key_pem = NULL;
static char *cert_pem = NULL;

static int parse_argv(int argc, char *argv[]) {
        enum {
                ARG_VERSION = 0x100,
                ARG_KEY,
                ARG_CERT,
        };

        int r, c;

        static const struct option options[] = {
                { "help",    no_argument,       NULL, 'h'         },
                { "version", no_argument,       NULL, ARG_VERSION },
                { "key",     required_argument, NULL, ARG_KEY     },
                { "cert",    required_argument, NULL, ARG_CERT    },
                { NULL,      0,                 NULL, 0           }
        };

        assert(argc >= 0);
        assert(argv);

        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
                switch(c) {
                case ARG_VERSION:
                        puts(PACKAGE_STRING);
                        puts(SYSTEMD_FEATURES);
                        return 0;

                case 'h':
                        return help();

                case ARG_KEY:
                        if (key_pem) {
                                log_error("Key file specified twice");
                                return -EINVAL;
                        }
                        r = read_full_file(optarg, &key_pem, NULL);
                        if (r < 0) {
                                log_error("Failed to read key file: %s", strerror(-r));
                                return r;
                        }
                        assert(key_pem);
                        break;

                case ARG_CERT:
                        if (cert_pem) {
                                log_error("Certificate file specified twice");
                                return -EINVAL;
                        }
                        r = read_full_file(optarg, &cert_pem, NULL);
                        if (r < 0) {
                                log_error("Failed to read certificate file: %s", strerror(-r));
                                return r;
                        }
                        assert(cert_pem);
                        break;

                case '?':
                        return -EINVAL;

                default:
                        log_error("Unknown option code %c", c);
                        return -EINVAL;
                }

        if (optind < argc) {
                log_error("This program does not take arguments.");
                return -EINVAL;
        }

        if (!!key_pem != !!cert_pem) {
                log_error("Certificate and key files must be specified together");
                return -EINVAL;
        }

        return 1;
}

int main(int argc, char *argv[]) {
        struct MHD_Daemon *d = NULL;
        int r, n;

        log_set_target(LOG_TARGET_AUTO);
        log_parse_environment();
        log_open();

        r = parse_argv(argc, argv);
        if (r < 0)
                return EXIT_FAILURE;
        if (r == 0)
                return EXIT_SUCCESS;

        n = sd_listen_fds(1);
        if (n < 0) {
                log_error("Failed to determine passed sockets: %s", strerror(-n));
                goto finish;
        } else if (n > 1) {
                log_error("Can't listen on more than one socket.");
                goto finish;
        } else {
                struct MHD_OptionItem opts[] = {
                        { MHD_OPTION_NOTIFY_COMPLETED,
                          (intptr_t) request_meta_free, NULL },
                        { MHD_OPTION_EXTERNAL_LOGGER,
                          (intptr_t) microhttpd_logger, NULL },
                        { MHD_OPTION_END, 0, NULL },
                        { MHD_OPTION_END, 0, NULL },
                        { MHD_OPTION_END, 0, NULL },
                        { MHD_OPTION_END, 0, NULL }};
                int opts_pos = 2;
                int flags = MHD_USE_THREAD_PER_CONNECTION|MHD_USE_POLL|MHD_USE_DEBUG;

                if (n > 0)
                        opts[opts_pos++] = (struct MHD_OptionItem)
                                {MHD_OPTION_LISTEN_SOCKET, SD_LISTEN_FDS_START};
                if (key_pem) {
                        assert(cert_pem);
                        opts[opts_pos++] = (struct MHD_OptionItem)
                                {MHD_OPTION_HTTPS_MEM_KEY, 0, key_pem};
                        opts[opts_pos++] = (struct MHD_OptionItem)
                                {MHD_OPTION_HTTPS_MEM_CERT, 0, cert_pem};
                        flags |= MHD_USE_SSL;
                }

                d = MHD_start_daemon(flags, 19531,
                                     NULL, NULL,
                                     request_handler, NULL,
                                     MHD_OPTION_ARRAY, opts,
                                     MHD_OPTION_END);
        }

        if (!d) {
                log_error("Failed to start daemon!");
                goto finish;
        }

        pause();

        r = EXIT_SUCCESS;

finish:
        if (d)
                MHD_stop_daemon(d);

        return r;
}