[PATCH v3] Add support for /dev/[u]random ioctls

Rasmus Villemoes rasmus.villemoes at prevas.dk
Mon Nov 5 17:29:00 UTC 2018


* random_ioctl.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* defs.h (DECL_IOCTL): Add random.
* ioctl.c (ioctl_decode): Add 'R' case.
* xlat/random_ioctl_cmds.in: New file.
* tests/ioctl_random.c: New file.
* tests/.gitignore: Add ioctl_random.
* tests/pure_executables.list: Likewise.
* tests/gen_tests.in (ioctl_random): New entry.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes at prevas.dk>
---
v2:
* Use proper helpers for printing int* and struct fields
* Add printing of buffer contents for RNDADDENTROPY
* Add tests

v3:
* Fix whitespace issues (sorry)
* Define RNDRESEEDCRNG in xlat/random_ioctl_cmds.in, use
  unconditionally.
* Fix copy-pasto (nbd_ioctl_cmds.h -> random_ioctl_cmds.h)

 Makefile.am                 |  1 +
 defs.h                      |  1 +
 ioctl.c                     |  2 ++
 random_ioctl.c              | 53 +++++++++++++++++++++++++++++++++++++
 tests/.gitignore            |  1 +
 tests/gen_tests.in          |  1 +
 tests/ioctl_random.c        | 44 ++++++++++++++++++++++++++++++
 tests/pure_executables.list |  1 +
 xlat/random_ioctl_cmds.in   |  7 +++++
 9 files changed, 111 insertions(+)
 create mode 100644 random_ioctl.c
 create mode 100644 tests/ioctl_random.c
 create mode 100644 xlat/random_ioctl_cmds.in

diff --git a/Makefile.am b/Makefile.am
index 913d26a9..0680763e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -267,6 +267,7 @@ strace_SOURCES =	\
 	ptp.c		\
 	ptrace.h	\
 	quota.c		\
+	random_ioctl.c	\
 	readahead.c	\
 	readlink.c	\
 	reboot.c	\
diff --git a/defs.h b/defs.h
index 5ba95f53..b8d561aa 100644
--- a/defs.h
+++ b/defs.h
@@ -973,6 +973,7 @@ DECL_IOCTL(kvm);
 DECL_IOCTL(nbd);
 DECL_IOCTL(nsfs);
 DECL_IOCTL(ptp);
+DECL_IOCTL(random);
 DECL_IOCTL(scsi);
 DECL_IOCTL(term);
 DECL_IOCTL(ubi);
diff --git a/ioctl.c b/ioctl.c
index 4c9e7db3..e7dd4c4e 100644
--- a/ioctl.c
+++ b/ioctl.c
@@ -329,6 +329,8 @@ ioctl_decode(struct tcb *tcp)
 		return inotify_ioctl(tcp, code, arg);
 	case 0xab:
 		return nbd_ioctl(tcp, code, arg);
+	case 'R':
+		return random_ioctl(tcp, code, arg);
 	default:
 		break;
 	}
diff --git a/random_ioctl.c b/random_ioctl.c
new file mode 100644
index 00000000..878c00ff
--- /dev/null
+++ b/random_ioctl.c
@@ -0,0 +1,53 @@
+#include "defs.h"
+#include "print_fields.h"
+
+#include <linux/random.h>
+
+#define XLAT_MACROS_ONLY
+# include "xlat/random_ioctl_cmds.h"
+#undef XLAT_MACROS_ONLY
+
+/*
+ * RNDGETPOOL was removed in 2.6.9, so non-ancient kernels always
+ * return -EINVAL for that.
+ */
+
+int
+random_ioctl(struct tcb *const tcp, const unsigned int code,
+	   const kernel_ulong_t arg)
+{
+	struct rand_pool_info info;
+	kernel_ulong_t buf;
+
+	switch (code) {
+	case RNDGETENTCNT:
+		if (entering(tcp))
+			return 0;
+		ATTRIBUTE_FALLTHROUGH;
+	case RNDADDTOENTCNT:
+		tprints(", ");
+		printnum_int(tcp, arg, "%d");
+		break;
+
+	case RNDADDENTROPY:
+		tprints(", ");
+		if (!umove_or_printaddr(tcp, arg, &info)) {
+			PRINT_FIELD_D("{", info, entropy_count);
+			PRINT_FIELD_D(", ", info, buf_size);
+			tprints(", buf=");
+			buf = arg + offsetof(struct rand_pool_info, buf);
+			printstrn(tcp, buf, info.buf_size);
+			tprints("}");
+		}
+		break;
+
+	/* ioctls with no parameters */
+	case RNDZAPENTCNT:
+	case RNDCLEARPOOL:
+	case RNDRESEEDCRNG:
+		break;
+	default:
+		return RVAL_DECODED;
+	}
+	return RVAL_IOCTL_DECODED;
+}
diff --git a/tests/.gitignore b/tests/.gitignore
index 577a1316..297319ef 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -158,6 +158,7 @@ ioctl_nsfs
 ioctl_perf
 ioctl_perf-success
 ioctl_ptp
+ioctl_random
 ioctl_rtc
 ioctl_rtc-v
 ioctl_scsi
diff --git a/tests/gen_tests.in b/tests/gen_tests.in
index cd63788d..f36cb62f 100644
--- a/tests/gen_tests.in
+++ b/tests/gen_tests.in
@@ -150,6 +150,7 @@ ioctl_nbd	+ioctl.test -y
 ioctl_nsfs	+ioctl.test -esignal=none
 ioctl_perf	+ioctl.test
 ioctl_ptp 	+ioctl.test
+ioctl_random	+ioctl.test
 ioctl_rtc	+ioctl.test
 ioctl_rtc-v	+ioctl.test -v
 ioctl_scsi	+ioctl.test
diff --git a/tests/ioctl_random.c b/tests/ioctl_random.c
new file mode 100644
index 00000000..284fc21a
--- /dev/null
+++ b/tests/ioctl_random.c
@@ -0,0 +1,44 @@
+#include "tests.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <linux/random.h>
+
+#define XLAT_MACROS_ONLY
+# include "xlat/random_ioctl_cmds.h"
+#undef XLAT_MACROS_ONLY
+
+#define RVAL_EBADF " = -1 EBADF (%m)\n"
+
+int
+main(void)
+{
+	union {
+		char c[sizeof(struct rand_pool_info) + 8];
+		struct rand_pool_info info;
+	} u;
+	struct rand_pool_info *info = &u.info;
+	int cnt = 6;
+
+	memcpy(info->buf, "12345678", 8);
+	info->buf_size = 8;
+	info->entropy_count = 3;
+
+	ioctl(-1, RNDGETENTCNT, &cnt);
+	printf("ioctl(-1, RNDGETENTCNT, %p)" RVAL_EBADF, &cnt);
+	ioctl(-1, RNDADDTOENTCNT, &cnt);
+	printf("ioctl(-1, RNDADDTOENTCNT, [6])" RVAL_EBADF);
+	ioctl(-1, RNDADDENTROPY, info);
+	printf("ioctl(-1, RNDADDENTROPY, {entropy_count=3, buf_size=8, buf=\"12345678\"})" RVAL_EBADF);
+
+	ioctl(-1, RNDZAPENTCNT);
+	printf("ioctl(-1, RNDZAPENTCNT)" RVAL_EBADF);
+	ioctl(-1, RNDCLEARPOOL);
+	printf("ioctl(-1, RNDCLEARPOOL)" RVAL_EBADF);
+	ioctl(-1, RNDRESEEDCRNG);
+	printf("ioctl(-1, RNDRESEEDCRNG)" RVAL_EBADF);
+
+	puts("+++ exited with 0 +++");
+	return 0;
+}
diff --git a/tests/pure_executables.list b/tests/pure_executables.list
index 69097bfb..d787f78e 100755
--- a/tests/pure_executables.list
+++ b/tests/pure_executables.list
@@ -121,6 +121,7 @@ ioctl_mtd
 ioctl_nbd
 ioctl_perf
 ioctl_ptp
+ioctl_random
 ioctl_rtc
 ioctl_scsi
 ioctl_sg_io_v3
diff --git a/xlat/random_ioctl_cmds.in b/xlat/random_ioctl_cmds.in
new file mode 100644
index 00000000..1b31dc52
--- /dev/null
+++ b/xlat/random_ioctl_cmds.in
@@ -0,0 +1,7 @@
+RNDGETENTCNT		_IOR( 'R', 0x00, int )
+RNDADDTOENTCNT		_IOW( 'R', 0x01, int )
+RNDGETPOOL		_IOR( 'R', 0x02, int [2] )
+RNDADDENTROPY		_IOW( 'R', 0x03, int [2] )
+RNDZAPENTCNT		_IO( 'R', 0x04 )
+RNDCLEARPOOL		_IO( 'R', 0x06 )
+RNDRESEEDCRNG		_IO( 'R', 0x07 )
-- 
2.19.1.6.gbde171bbf5



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