1 files changed, 266 insertions, 0 deletions
diff --git a/dev/haring/haring.c b/dev/haring/haring.c
new file mode 100644
index 0000000..ee7e1aa
--- /dev/null
+++ b/dev/haring/haring.c
@@ -0,0 +1,266 @@
+/*
+ * 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.
+ */
+/* we do not implement BUG_ON() */
+#undef DEBUG_STRICT
+
+#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
+int repair = 0; // repair file
+
+
+/* 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"
+	    "  -r           : \"repair\" corrupted file (actively search for message boundaries)\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 */
+		ofs = (flags & RING_WF_SEEK_NEW) ? buf.data - 1 : 0;
+
+		//HA_ATOMIC_INC(b_peek(&buf, ofs));
+	}
+
+	while (1) {
+		//HA_RWLOCK_RDLOCK(RING_LOCK, &ring->lock);
+
+		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)) {
+			if (unlikely(repair && *b_peek(&buf, ofs))) {
+				/* in repair mode we consider that we could have landed
+				 * in the middle of a message so we skip all bytes till
+				 * the next zero.
+				 */
+				ofs++;
+				continue;
+			}
+			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));
+		//HA_RWLOCK_RDUNLOCK(RING_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], "-r") == 0)
+			repair = 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:
+ */