Decode /dev/loop ioctls

Needed to debug some losetup failures, and it's easier when you can see
what the kernel is getting vs what you think you're sending, so add some
decoders for those ioctls.

* loop.c: New file.
* Makefile.am (strace_SOURCES): Add loop.c.
* defs.h (loop_ioctl): New prototype.
(string_quote): Likewise.
* ioctl.c (ioctl_decode): Call loop_ioctl when code is 'L'.
* util.c (string_quote): Remove static keyword.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/loop.c b/loop.c
new file mode 100644
index 0000000..a350135
--- /dev/null
+++ b/loop.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (c) 2012 The Chromium OS Authors.
+ * Written by Mike Frysinger <vapier@gentoo.org>.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "defs.h"
+
+#include <sys/ioctl.h>
+
+#include <linux/loop.h>
+
+static const struct xlat loop_flags_options[] = {
+	{ LO_FLAGS_READ_ONLY,	"LO_FLAGS_READ_ONLY"	},
+	{ LO_FLAGS_AUTOCLEAR,	"LO_FLAGS_AUTOCLEAR"	},
+#ifdef LO_FLAGS_PARTSCAN
+	{ LO_FLAGS_PARTSCAN,	"LO_FLAGS_PARTSCAN"	},
+#endif
+	{ 0,			NULL			},
+};
+
+static const struct xlat loop_crypt_type_options[] = {
+	{ LO_CRYPT_NONE,	"LO_CRYPT_NONE"		},
+	{ LO_CRYPT_XOR,		"LO_CRYPT_XOR"		},
+	{ LO_CRYPT_DES,		"LO_CRYPT_DES"		},
+	{ LO_CRYPT_FISH2,	"LO_CRYPT_FISH2"	},
+	{ LO_CRYPT_BLOW,	"LO_CRYPT_BLOW"		},
+	{ LO_CRYPT_CAST128,	"LO_CRYPT_CAST128"	},
+	{ LO_CRYPT_IDEA,	"LO_CRYPT_IDEA"		},
+	{ LO_CRYPT_DUMMY,	"LO_CRYPT_DUMMY"	},
+	{ LO_CRYPT_SKIPJACK,	"LO_CRYPT_SKIPJACK"	},
+	{ LO_CRYPT_CRYPTOAPI,	"LO_CRYPT_CRYPTOAPI"	},
+	{ 0,			NULL			},
+};
+
+int loop_ioctl(struct tcb *tcp, long code, long arg)
+{
+	struct loop_info info;
+	struct loop_info64 info64;
+	char *s = alloca((LO_NAME_SIZE + LO_KEY_SIZE) * 4);
+
+	if (entering(tcp))
+		return 0;
+
+	switch (code) {
+
+	case LOOP_SET_STATUS:
+	case LOOP_GET_STATUS:
+		if (!verbose(tcp) || umove(tcp, arg, &info) < 0)
+			return 0;
+
+		tprintf(", {number=%i", info.lo_number);
+
+		if (!abbrev(tcp)) {
+			tprintf(", device=%#lx, inode=%lu, rdevice=%#lx",
+				(unsigned long) info.lo_device,
+				info.lo_inode,
+				(unsigned long) info.lo_rdevice);
+		}
+
+		tprintf(", offset=%#x", info.lo_offset);
+
+		if (!abbrev(tcp) || info.lo_encrypt_type != LO_CRYPT_NONE) {
+			tprints(", encrypt_type=");
+			printxval(loop_crypt_type_options, info.lo_encrypt_type,
+				"LO_CRYPT_???");
+			tprintf(", encrypt_key_size=%i", info.lo_encrypt_key_size);
+		}
+
+		tprints(", flags=");
+		printflags(loop_flags_options, info.lo_flags, "LO_FLAGS_???");
+
+		string_quote(info.lo_name, s, -1, LO_NAME_SIZE);
+		tprintf(", name=%s", s);
+
+		if (!abbrev(tcp) || info.lo_encrypt_type != LO_CRYPT_NONE) {
+			string_quote((void *) info.lo_encrypt_key, s, 0, LO_KEY_SIZE);
+			tprintf(", encrypt_key=%s", s);
+		}
+
+		if (!abbrev(tcp))
+			tprintf(", init={%#lx, %#lx}"
+				", reserved={%#x, %#x, %#x, %#x}}",
+				info.lo_init[0], info.lo_init[1],
+				info.reserved[0], info.reserved[1],
+				info.reserved[2], info.reserved[3]);
+		else
+			tprints(", ...}");
+
+		return 1;
+
+	case LOOP_SET_STATUS64:
+	case LOOP_GET_STATUS64:
+		if (!verbose(tcp) || umove(tcp, arg, &info64) < 0)
+			return 0;
+
+		tprints(", {");
+
+		if (!abbrev(tcp)) {
+			tprintf("device=%" PRIu64 ", inode=%" PRIu64 ", "
+				"rdevice=%" PRIu64 ", offset=%#" PRIx64 ", "
+				"sizelimit=%" PRIu64 ", number=%" PRIu32,
+				(uint64_t) info64.lo_device,
+				(uint64_t) info64.lo_inode,
+				(uint64_t) info64.lo_rdevice,
+				(uint64_t) info64.lo_offset,
+				(uint64_t) info64.lo_sizelimit,
+				(uint32_t) info64.lo_number);
+		} else {
+			tprintf("offset=%#" PRIx64 ", number=%" PRIu32,
+				(uint64_t) info64.lo_offset,
+				(uint32_t) info64.lo_number);
+		}
+
+		if (!abbrev(tcp) || info64.lo_encrypt_type != LO_CRYPT_NONE) {
+			tprints(", encrypt_type=");
+			printxval(loop_crypt_type_options, info64.lo_encrypt_type,
+				"LO_CRYPT_???");
+			tprintf(", encrypt_key_size=%" PRIu32,
+				info64.lo_encrypt_key_size);
+		}
+
+		tprints(", flags=");
+		printflags(loop_flags_options, info64.lo_flags, "LO_FLAGS_???");
+
+		string_quote((void *) info64.lo_file_name, s, -1, LO_NAME_SIZE);
+		tprintf(", file_name=%s", s);
+
+		if (!abbrev(tcp) || info64.lo_encrypt_type != LO_CRYPT_NONE) {
+			string_quote((void *) info64.lo_crypt_name, s, -1, LO_NAME_SIZE);
+			tprintf(", crypt_name=%s", s);
+			string_quote((void *) info64.lo_encrypt_key, s, 0, LO_KEY_SIZE);
+			tprintf(", encrypt_key=%s", s);
+		}
+
+		if (!abbrev(tcp))
+			tprintf(", init={%#" PRIx64 ", %#" PRIx64 "}}",
+				(uint64_t) info64.lo_init[0],
+				(uint64_t) info64.lo_init[1]);
+		else
+			tprints(", ...}");
+
+		return 1;
+
+	case LOOP_CLR_FD:
+	case LOOP_SET_CAPACITY:
+#ifdef LOOP_CTL_GET_FREE
+	/* newer loop-control stuff */
+	case LOOP_CTL_GET_FREE:
+#endif
+		/* Takes no arguments */
+		return 1;
+
+	case LOOP_SET_FD:
+	case LOOP_CHANGE_FD:
+#ifdef LOOP_CTL_ADD
+	/* newer loop-control stuff */
+	case LOOP_CTL_ADD:
+	case LOOP_CTL_REMOVE:
+#endif
+		/* These take simple args, so let default printer handle it */
+
+	default:
+		return 0;
+	}
+}