dev/haring/haring.c - haproxy - Gitiles

 /*
  * post-mortem ring reader for haproxy
  *
  * Copyright (C) 2022 Willy Tarreau <w@1wt.eu>
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
  * "Software"), to deal in the Software without restriction, including
  * without limitation the rights to use, copy, modify, merge, publish,
  * distribute, sublicense, and/or sell copies of the Software, and to
  * permit persons to whom the Software is furnished to do so, subject to
  * the following conditions:
  *
  * The above copyright notice and this permission notice shall be
  * included in all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  */

 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>

 #include <haproxy/api.h>
 #include <haproxy/buf.h>
 #include <haproxy/ring.h>

 int force = 0; // force access to a different layout
 int lfremap = 0; // remap LF in traces


 /* display the message and exit with the code */
 __attribute__((noreturn)) void die(int code, const char *format, ...)
 {
 	va_list args;

 	if (format) {
 		va_start(args, format);
 		vfprintf(stderr, format, args);
 		va_end(args);
 	}
 	exit(code);
 }

 /* display the usage message and exit with the code */
 __attribute__((noreturn)) void usage(int code, const char *arg0)
 {
 	die(code,
 	    "Usage: %s [options]* <file>\n"
 	    "\n"
 	    "options :\n"
 	    "  -f           : force accessing a non-matching layout for 'ring struct'\n"
 	    "  -l           : replace LF in contents with CR VT\n"
 	    "\n"
 	    "", arg0);
 }

 /* This function dumps all events from the ring whose pointer is in <p0> into
  * the appctx's output buffer, and takes from <o0> the seek offset into the
  * buffer's history (0 for oldest known event). It looks at <i0> for boolean
  * options: bit0 means it must wait for new data or any key to be pressed. Bit1
  * means it must seek directly to the end to wait for new contents. It returns
  * 0 if the output buffer or events are missing is full and it needs to be
  * called again, otherwise non-zero. It is meant to be used with
  * cli_release_show_ring() to clean up.
  */
 int dump_ring(struct ring *ring, size_t ofs, int flags)
 {
 	struct buffer buf;
 	uint64_t msg_len = 0;
 	size_t len, cnt;
 	const char *blk1 = NULL, *blk2 = NULL, *p;
 	size_t len1 = 0, len2 = 0, bl;

 	/* Explanation: the storage area in the writing process starts after
 	 * the end of the structure. Since the whole area is mmapped(), we know
 	 * it starts at 0 mod 4096, hence the buf->area pointer's 12 LSB point
 	 * to the relative offset of the storage area. As there will always be
 	 * users using the wrong version of the tool with a dump, we need to
 	 * run a few checks first. After that we'll create our own buffer
 	 * descriptor matching that area.
 	 */
 	if ((((long)ring->buf.area) & 4095) != sizeof(*ring)) {
 		if (!force) {
 			fprintf(stderr, "FATAL: header in file is %ld bytes long vs %ld expected!\n",
 				(((long)ring->buf.area) & 4095),
 				(long)sizeof(*ring));
 			exit(1);
 		}
 		else {
 			fprintf(stderr, "WARNING: header in file is %ld bytes long vs %ld expected!\n",
 				(((long)ring->buf.area) & 4095),
 				(long)sizeof(*ring));
 		}
 		/* maybe we could emit a warning at least ? */
 	}

 	/* Now make our own buffer pointing to that area */
 	buf = b_make(((void *)ring + (((long)ring->buf.area) & 4095)),
 		     ring->buf.size, ring->buf.head, ring->buf.data);

 	/* explanation for the initialization below: it would be better to do
 	 * this in the parsing function but this would occasionally result in
 	 * dropped events because we'd take a reference on the oldest message
 	 * and keep it while being scheduled. Thus instead let's take it the
 	 * first time we enter here so that we have a chance to pass many
 	 * existing messages before grabbing a reference to a location. This
 	 * value cannot be produced after initialization.
 	 */
 	if (unlikely(ofs == ~0)) {
 		ofs = 0;

 		/* going to the end means looking at tail-1 */
 		if (flags & RING_WF_SEEK_NEW)
 			ofs += b_data(&buf) - 1;

 		//HA_ATOMIC_INC(b_peek(&buf, ofs));
 		ofs += ring->ofs;
 	}

 	while (1) {
 		//HA_RWLOCK_RDLOCK(LOGSRV_LOCK, &ring->lock);

 		/* we were already there, adjust the offset to be relative to
 		 * the buffer's head and remove us from the counter.
 		 */
 		ofs -= ring->ofs;
 		if (ofs >= buf.size) {
 			fprintf(stderr, "FATAL error at %d\n", __LINE__);
 			return 1;
 		}
 		//HA_ATOMIC_DEC(b_peek(&buf, ofs));

 		/* in this loop, ofs always points to the counter byte that precedes
 		 * the message so that we can take our reference there if we have to
 		 * stop before the end.
 		 */
 		while (ofs + 1 < b_data(&buf)) {
 			cnt = 1;
 			len = b_peek_varint(&buf, ofs + cnt, &msg_len);
 			if (!len)
 				break;
 			cnt += len;

 			if (msg_len + ofs + cnt + 1 > buf.data) {
 				fprintf(stderr, "FATAL error at %d\n", __LINE__);
 				return 1;
 			}

 			len = b_getblk_nc(&buf, &blk1, &len1, &blk2, &len2, ofs + cnt, msg_len);
 			if (!lfremap) {
 				if (len > 0 && len1)
 					fwrite(blk1, len1, 1, stdout);
 				if (len > 1 && len2)
 					fwrite(blk2, len2, 1, stdout);
 			} else {
 				while (len > 0) {
 					for (; len1; p++) {
 						p = memchr(blk1, '\n', len1);
 						if (!p || p > blk1) {
 							bl = p ? p - blk1 : len1;
 							fwrite(blk1, bl, 1, stdout);
 							blk1 += bl;
 							len1 -= bl;
 						}

 						if (p) {
 							putchar('\r');
 							putchar('\v');
 							blk1++;
 							len1--;
 						}
 					}
 					len--;
 					blk1 = blk2;
 					len1 = len2;
 				}
 			}

 			putchar('\n');

 			ofs += cnt + msg_len;
 		}

 		//HA_ATOMIC_INC(b_peek(&buf, ofs));
 		ofs += ring->ofs;
 		//HA_RWLOCK_RDUNLOCK(LOGSRV_LOCK, &ring->lock);

 		if (!(flags & RING_WF_WAIT_MODE))
 			break;

 		/* pause 10ms before checking for new stuff */
 		usleep(10000);
 	}
 	return 0;
 }

 int main(int argc, char **argv)
 {
 	struct ring *ring;
 	struct stat statbuf;
 	const char *arg0;
 	int fd;

 	arg0 = argv[0];
 	while (argc > 1 && argv[1][0] == '-') {
 		argc--; argv++;
 		if (strcmp(argv[0], "-f") == 0)
 			force = 1;
 		else if (strcmp(argv[0], "-l") == 0)
 			lfremap = 1;
 		else if (strcmp(argv[0], "--") == 0)
 			break;
 		else
 			usage(1, arg0);
 	}

 	if (argc < 2)
 		usage(1, arg0);

 	fd = open(argv[1], O_RDONLY);
 	if (fd < 0) {
 		perror("open()");
 		return 1;
 	}

 	if (fstat(fd, &statbuf) < 0) {
 		perror("fstat()");
 		return 1;
 	}

 	ring = mmap(NULL, statbuf.st_size, PROT_READ, MAP_SHARED, fd, 0);
 	close(fd);

 	if (ring == MAP_FAILED) {
 		perror("mmap()");
 		return 1;
 	}

 	return dump_ring(ring, ~0, 0);
 }


 /*
  * Local variables:
  *  c-indent-level: 8
  *  c-basic-offset: 8
  * End:
  */
	/*
	* post-mortem ring reader for haproxy
	*
	* Copyright (C) 2022 Willy Tarreau <w@1wt.eu>
	*
	* Permission is hereby granted, free of charge, to any person obtaining
	* a copy of this software and associated documentation files (the
	* "Software"), to deal in the Software without restriction, including
	* without limitation the rights to use, copy, modify, merge, publish,
	* distribute, sublicense, and/or sell copies of the Software, and to
	* permit persons to whom the Software is furnished to do so, subject to
	* the following conditions:
	*
	* The above copyright notice and this permission notice shall be
	* included in all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
	* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
	* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
	* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
	* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
	* OTHER DEALINGS IN THE SOFTWARE.
	*/

	#include <sys/mman.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <stdarg.h>
	#include <stdio.h>
	#include <stdlib.h>

	#include <haproxy/api.h>
	#include <haproxy/buf.h>
	#include <haproxy/ring.h>

	int force = 0; // force access to a different layout
	int lfremap = 0; // remap LF in traces


	/* display the message and exit with the code */
	__attribute__((noreturn)) void die(int code, const char *format, ...)
	{
	va_list args;

	if (format) {
	va_start(args, format);
	vfprintf(stderr, format, args);
	va_end(args);
	}
	exit(code);
	}

	/* display the usage message and exit with the code */
	__attribute__((noreturn)) void usage(int code, const char *arg0)
	{
	die(code,
	"Usage: %s [options]* <file>\n"
	"\n"
	"options :\n"
	" -f : force accessing a non-matching layout for 'ring struct'\n"
	" -l : replace LF in contents with CR VT\n"
	"\n"
	"", arg0);
	}

	/* This function dumps all events from the ring whose pointer is in <p0> into
	* the appctx's output buffer, and takes from <o0> the seek offset into the
	* buffer's history (0 for oldest known event). It looks at <i0> for boolean
	* options: bit0 means it must wait for new data or any key to be pressed. Bit1
	* means it must seek directly to the end to wait for new contents. It returns
	* 0 if the output buffer or events are missing is full and it needs to be
	* called again, otherwise non-zero. It is meant to be used with
	* cli_release_show_ring() to clean up.
	*/
	int dump_ring(struct ring *ring, size_t ofs, int flags)
	{
	struct buffer buf;
	uint64_t msg_len = 0;
	size_t len, cnt;
	const char blk1 = NULL, blk2 = NULL, *p;
	size_t len1 = 0, len2 = 0, bl;

	/* Explanation: the storage area in the writing process starts after
	* the end of the structure. Since the whole area is mmapped(), we know
	* it starts at 0 mod 4096, hence the buf->area pointer's 12 LSB point
	* to the relative offset of the storage area. As there will always be
	* users using the wrong version of the tool with a dump, we need to
	* run a few checks first. After that we'll create our own buffer
	* descriptor matching that area.
	*/
	if ((((long)ring->buf.area) & 4095) != sizeof(*ring)) {
	if (!force) {
	fprintf(stderr, "FATAL: header in file is %ld bytes long vs %ld expected!\n",
	(((long)ring->buf.area) & 4095),
	(long)sizeof(*ring));
	exit(1);
	}
	else {
	fprintf(stderr, "WARNING: header in file is %ld bytes long vs %ld expected!\n",
	(((long)ring->buf.area) & 4095),
	(long)sizeof(*ring));
	}
	/* maybe we could emit a warning at least ? */
	}

	/* Now make our own buffer pointing to that area */
	buf = b_make(((void *)ring + (((long)ring->buf.area) & 4095)),
	ring->buf.size, ring->buf.head, ring->buf.data);

	/* explanation for the initialization below: it would be better to do
	* this in the parsing function but this would occasionally result in
	* dropped events because we'd take a reference on the oldest message
	* and keep it while being scheduled. Thus instead let's take it the
	* first time we enter here so that we have a chance to pass many
	* existing messages before grabbing a reference to a location. This
	* value cannot be produced after initialization.
	*/
	if (unlikely(ofs == ~0)) {
	ofs = 0;

	/* going to the end means looking at tail-1 */
	if (flags & RING_WF_SEEK_NEW)
	ofs += b_data(&buf) - 1;

	//HA_ATOMIC_INC(b_peek(&buf, ofs));
	ofs += ring->ofs;
	}

	while (1) {
	//HA_RWLOCK_RDLOCK(LOGSRV_LOCK, &ring->lock);

	/* we were already there, adjust the offset to be relative to
	* the buffer's head and remove us from the counter.
	*/
	ofs -= ring->ofs;
	if (ofs >= buf.size) {
	fprintf(stderr, "FATAL error at %d\n", __LINE__);
	return 1;
	}
	//HA_ATOMIC_DEC(b_peek(&buf, ofs));

	/* in this loop, ofs always points to the counter byte that precedes
	* the message so that we can take our reference there if we have to
	* stop before the end.
	*/
	while (ofs + 1 < b_data(&buf)) {
	cnt = 1;
	len = b_peek_varint(&buf, ofs + cnt, &msg_len);
	if (!len)
	break;
	cnt += len;

	if (msg_len + ofs + cnt + 1 > buf.data) {
	fprintf(stderr, "FATAL error at %d\n", __LINE__);
	return 1;
	}

	len = b_getblk_nc(&buf, &blk1, &len1, &blk2, &len2, ofs + cnt, msg_len);
	if (!lfremap) {
	if (len > 0 && len1)
	fwrite(blk1, len1, 1, stdout);
	if (len > 1 && len2)
	fwrite(blk2, len2, 1, stdout);
	} else {
	while (len > 0) {
	for (; len1; p++) {
	p = memchr(blk1, '\n', len1);
	if (!p \|\| p > blk1) {
	bl = p ? p - blk1 : len1;
	fwrite(blk1, bl, 1, stdout);
	blk1 += bl;
	len1 -= bl;
	}

	if (p) {
	putchar('\r');
	putchar('\v');
	blk1++;
	len1--;
	}
	}
	len--;
	blk1 = blk2;
	len1 = len2;
	}
	}

	putchar('\n');

	ofs += cnt + msg_len;
	}

	//HA_ATOMIC_INC(b_peek(&buf, ofs));
	ofs += ring->ofs;
	//HA_RWLOCK_RDUNLOCK(LOGSRV_LOCK, &ring->lock);

	if (!(flags & RING_WF_WAIT_MODE))
	break;

	/* pause 10ms before checking for new stuff */
	usleep(10000);
	}
	return 0;
	}

	int main(int argc, char **argv)
	{
	struct ring *ring;
	struct stat statbuf;
	const char *arg0;
	int fd;

	arg0 = argv[0];
	while (argc > 1 && argv[1][0] == '-') {
	argc--; argv++;
	if (strcmp(argv[0], "-f") == 0)
	force = 1;
	else if (strcmp(argv[0], "-l") == 0)
	lfremap = 1;
	else if (strcmp(argv[0], "--") == 0)
	break;
	else
	usage(1, arg0);
	}

	if (argc < 2)
	usage(1, arg0);

	fd = open(argv[1], O_RDONLY);
	if (fd < 0) {
	perror("open()");
	return 1;
	}

	if (fstat(fd, &statbuf) < 0) {
	perror("fstat()");
	return 1;
	}

	ring = mmap(NULL, statbuf.st_size, PROT_READ, MAP_SHARED, fd, 0);
	close(fd);

	if (ring == MAP_FAILED) {
	perror("mmap()");
	return 1;
	}

	return dump_ring(ring, ~0, 0);
	}


	/*
	* Local variables:
	* c-indent-level: 8
	* c-basic-offset: 8
	* End:
	*/