/*
	 * Copyright (C) 2011 Red Hat, Inc.
	 *
	 * All rights reserved.
	 *
	 * Author: Angus Salkeld <asalkeld@redhat.com>
	 *
	 * libqb is free software: you can redistribute it and/or modify
	 * it under the terms of the GNU Lesser General Public License as published by
	 * the Free Software Foundation, either version 2.1 of the License, or
	 * (at your option) any later version.
	 *
	 * libqb is distributed in the hope that it will be useful,
	 * but WITHOUT ANY WARRANTY; without even the implied warranty of
	 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	 * GNU Lesser General Public License for more details.
	 *
	 * You should have received a copy of the GNU Lesser General Public License
	 * along with libqb.  If not, see <http://www.gnu.org/licenses/>.
	 */
	#include "os_base.h"
	
	#include <qb/qbrb.h>
	#include "util_int.h"
	#include "log_int.h"
	#include "ringbuffer_int.h"
	
	#define BB_MIN_ENTRY_SIZE (4 * sizeof(uint32_t) +\
				   sizeof(uint8_t) +\
				   2 * sizeof(char) + sizeof(time_t))
	
	
	static void
	_blackbox_reload(int32_t target)
	{
		struct qb_log_target *t = qb_log_target_get(target);
	
		if (t->instance == NULL) {
			return;
		}
		qb_rb_close(t->instance);
		t->instance = qb_rb_open(t->filename, t->size,
					 QB_RB_FLAG_CREATE | QB_RB_FLAG_OVERWRITE, 0);
	}
	
	/* <u32> file lineno
	 * <u32> tags
	 * <u8> priority
	 * <u32> function name length
	 * <string> function name
	 * <u32> buffer length
	 * <string> buffer
	 */
	static void
	_blackbox_vlogger(int32_t target,
			  struct qb_log_callsite *cs, struct timespec *timestamp, va_list ap)
	{
		size_t max_size;
		size_t actual_size;
		uint32_t fn_size;
		char *chunk;
		char *msg_len_pt;
		uint32_t msg_len;
		struct qb_log_target *t = qb_log_target_get(target);
	
		if (t->instance == NULL) {
			return;
		}
	
		fn_size = strlen(cs->function) + 1;
	
		actual_size = 4 * sizeof(uint32_t) + sizeof(uint8_t) + fn_size + sizeof(struct timespec);
		max_size = actual_size + t->max_line_length;
	
		chunk = qb_rb_chunk_alloc(t->instance, max_size);
	
		if (chunk == NULL) {
			/* something bad has happened. abort blackbox logging */
			qb_util_perror(LOG_ERR, "Blackbox allocation error, aborting blackbox log %s", t->filename);
			qb_rb_close(qb_rb_lastref_and_ret(
				(struct qb_ringbuffer_s **) &t->instance
			));
			return;
		}
	
		/* line number */
		memcpy(chunk, &cs->lineno, sizeof(uint32_t));
		chunk += sizeof(uint32_t);
	
		/* tags */
		memcpy(chunk, &cs->tags, sizeof(uint32_t));
		chunk += sizeof(uint32_t);
	
		/* log level/priority */
		memcpy(chunk, &cs->priority, sizeof(uint8_t));
		chunk += sizeof(uint8_t);
	
		/* function name */
		memcpy(chunk, &fn_size, sizeof(uint32_t));
		chunk += sizeof(uint32_t);
		memcpy(chunk, cs->function, fn_size);
		chunk += fn_size;
	
		/* timestamp */
		memcpy(chunk, timestamp, sizeof(struct timespec));
		chunk += sizeof(struct timespec);
	
		/* log message length */
		msg_len_pt = chunk;
		chunk += sizeof(uint32_t);
	
		/* log message */
		msg_len = qb_vsnprintf_serialize(chunk, t->max_line_length, cs->format, ap);
		if (msg_len >= t->max_line_length) {
		    chunk = msg_len_pt + sizeof(uint32_t); /* Reset */
	
		    /* Leave this at QB_LOG_MAX_LEN so as not to overflow the blackbox */
		    msg_len = qb_vsnprintf_serialize(chunk, QB_LOG_MAX_LEN,
			"Log message too long to be stored in the blackbox.  "\
			"Maximum is QB_LOG_MAX_LEN" , ap);
		}
	
		actual_size += msg_len;
	
		/* now that we know the length, write it
		 */
		memcpy(msg_len_pt, &msg_len, sizeof(uint32_t));
	
		(void)qb_rb_chunk_commit(t->instance, actual_size);
	}
	
	static void
	_blackbox_close(int32_t target)
	{
		struct qb_log_target *t = qb_log_target_get(target);
	
		qb_rb_close(qb_rb_lastref_and_ret(
			(struct qb_ringbuffer_s **) &t->instance
		));
	}
	
	int32_t
	qb_log_blackbox_open(struct qb_log_target *t)
	{
		if (t->size < 1024) {
			return -EINVAL;
		}
		snprintf(t->filename, PATH_MAX, "%s-%d-blackbox", t->name, getpid());
	
		t->instance = qb_rb_open(t->filename, t->size,
					 QB_RB_FLAG_CREATE | QB_RB_FLAG_OVERWRITE, 0);
		if (t->instance == NULL) {
			return -errno;
		}
	
		t->logger = NULL;
		t->vlogger = _blackbox_vlogger;
		t->reload = _blackbox_reload;
		t->close = _blackbox_close;
		return 0;
	}
	
	/*
	 * This is designed to look as much like the ringbuffer header
	 * as possible so that we can distinguish an old RB dump
	 * from a new one with this header.
	 */
	
	struct _blackbox_file_header {
		uint32_t word_size;
		uint32_t read_pt;
		uint32_t write_pt;
		uint32_t version;
		uint32_t hash;
	} __attribute__((packed));
	
	/* Values we expect for a 'new' header */
	#define QB_BLACKBOX_HEADER_WORDSIZE 0
	#define QB_BLACKBOX_HEADER_READPT   0xCCBBCCBB
	#define QB_BLACKBOX_HEADER_WRITEPT  0xBBCCBBCC
	#define QB_BLACKBOX_HEADER_VERSION  2
	#define QB_BLACKBOX_HEADER_HASH     0
	
	ssize_t
	qb_log_blackbox_write_to_file(const char *filename)
	{
		ssize_t written_size = 0;
		struct qb_log_target *t;
		struct _blackbox_file_header header;
		int fd = open(filename, O_CREAT | O_RDWR, 0700);
	
		if (fd < 0) {
			return -errno;
		}
	
		/* Write header, so we know this is a 'new' format blackbox */
		header.word_size = QB_BLACKBOX_HEADER_WORDSIZE;
		header.read_pt   = QB_BLACKBOX_HEADER_READPT;
		header.write_pt  = QB_BLACKBOX_HEADER_WRITEPT;
		header.version   = QB_BLACKBOX_HEADER_VERSION;
		header.hash      = QB_BLACKBOX_HEADER_HASH;
		written_size = write(fd, &header, sizeof(header));
		if (written_size < sizeof(header)) {
			close(fd);
			return written_size;
		}
	
		t = qb_log_target_get(QB_LOG_BLACKBOX);
		if (t->instance) {
			written_size += qb_rb_write_to_file(t->instance, fd);
		} else {
			written_size = -ENOENT;
		}
		close(fd);
	
		return written_size;
	}
	
	int
	qb_log_blackbox_print_from_file(const char *bb_filename)
	{
		qb_ringbuffer_t *instance;
		ssize_t bytes_read;
		int max_size = 2 * QB_LOG_MAX_LEN;
		char *chunk;
		int fd;
		int err = 0;
		int saved_errno;
		struct _blackbox_file_header header;
		int have_timespecs = 0;
		char time_buf[64];
	
		fd = open(bb_filename, 0);

		if (fd < 0) {
			saved_errno = errno;
			qb_util_perror(LOG_ERR, "qb_log_blackbox_print_from_file");
			return -saved_errno;

		}
	
		/* Read the header. If it looks like one of ours then
		   we know we have hi-res timestamps */
		err = read(fd, &header, sizeof(header));

		if (err < sizeof(header)) {
			saved_errno = errno;
			close(fd);
			return -saved_errno;

		}
	

		if (header.word_size == QB_BLACKBOX_HEADER_WORDSIZE &&
		    header.read_pt == QB_BLACKBOX_HEADER_READPT &&
		    header.write_pt == QB_BLACKBOX_HEADER_WRITEPT &&
		    header.version == QB_BLACKBOX_HEADER_VERSION &&
		    header.hash == QB_BLACKBOX_HEADER_HASH) {
			have_timespecs = 1;

		} else {
			(void)lseek(fd, 0, SEEK_SET);

		}
	
	

		instance = qb_rb_create_from_file(fd, 0);
		close(fd);

		if (instance == NULL) {
			return -EIO;

		}
		chunk = malloc(max_size);

		if (!chunk) {
			goto cleanup;

		}
	
		do {
			char *ptr;
			uint32_t lineno;
			uint32_t tags;
			uint8_t priority;
			uint32_t fn_size;
			char *function;
			uint32_t len;
			struct timespec timestamp;
			time_t time_sec;
			uint32_t msg_len;
			struct tm *tm;
			char message[QB_LOG_MAX_LEN];
	

			bytes_read = qb_rb_chunk_read(instance, chunk, max_size, 0);
	
			if (bytes_read >= 0 && bytes_read < BB_MIN_ENTRY_SIZE) {
				printf("ERROR Corrupt file: blackbox header too small.\n");
				err = -1;
				goto cleanup;
			} else if (bytes_read < 0) {
				errno = -bytes_read;
				perror("ERROR: qb_rb_chunk_read failed");
				err = -EIO;
				goto cleanup;
			}
			ptr = chunk;
	
			/* lineno */
			memcpy(&lineno, ptr, sizeof(uint32_t));
			ptr += sizeof(uint32_t);
	
			/* tags */
			memcpy(&tags, ptr, sizeof(uint32_t));
			ptr += sizeof(uint32_t);
	
			/* priority */
			memcpy(&priority, ptr, sizeof(uint8_t));
			ptr += sizeof(uint8_t);
	
			/* function size & name */
			memcpy(&fn_size, ptr, sizeof(uint32_t));
			if ((fn_size + BB_MIN_ENTRY_SIZE) > bytes_read) {
	#ifndef S_SPLINT_S
				printf("ERROR Corrupt file: fn_size way too big %" PRIu32 "\n", fn_size);
				err = -EIO;
	#endif /* S_SPLINT_S */
				goto cleanup;
			}
			if (fn_size <= 0) {
	#ifndef S_SPLINT_S
				printf("ERROR Corrupt file: fn_size negative %" PRIu32 "\n", fn_size);
				err = -EIO;
	#endif /* S_SPLINT_S */
				goto cleanup;
			}
			ptr += sizeof(uint32_t);
	
			function = ptr;
			ptr += fn_size;
	
			/* timestamp size & content */
			if (have_timespecs) {
				memcpy(&timestamp, ptr, sizeof(struct timespec));
				ptr += sizeof(struct timespec);
				time_sec = timestamp.tv_sec;
			} else {
				memcpy(&time_sec, ptr, sizeof(time_t));
				ptr += sizeof(time_t);
				timestamp.tv_nsec = 0LL;
			}
	
			tm = localtime(&time_sec);
			if (tm) {
				int slen = strftime(time_buf,
						    sizeof(time_buf), "%b %d %T",
						    tm);
				snprintf(time_buf+slen, sizeof(time_buf) - slen, ".%03llu", timestamp.tv_nsec/QB_TIME_NS_IN_MSEC);
			} else {
				snprintf(time_buf, sizeof(time_buf), "%ld",
					 (long int)time_sec);
			}
			/* message length */
			memcpy(&msg_len, ptr, sizeof(uint32_t));
			if (msg_len > QB_LOG_MAX_LEN || msg_len <= 0) {
	#ifndef S_SPLINT_S
				printf("ERROR Corrupt file: msg_len out of bounds %" PRIu32 "\n", msg_len);
				err = -EIO;
	#endif /* S_SPLINT_S */
				goto cleanup;
			}
	
			ptr += sizeof(uint32_t);
	
			/* message content */
			len = qb_vsnprintf_deserialize(message, QB_LOG_MAX_LEN, ptr);
			assert(len > 0);
			message[len] = '\0';
			len--;
			while (len > 0 && (message[len] == '\n' || message[len] == '\0')) {
				message[len] = '\0';
				len--;
			}
	
			printf("%-7s %s %s(%u):%u: %s\n",
			       qb_log_priority2str(priority),
			       time_buf, function, lineno, tags, message);
	
		} while (bytes_read > BB_MIN_ENTRY_SIZE);
	
	cleanup:
		qb_rb_close(instance);
		free(chunk);
		return err;
	}