From: Eugene Syromyatnikov <evgsyr@gmail.com>
Date: Thu, 25 Jan 2018 16:53:23 +0000 (+0100)
Subject: printfd: print character/block device number in -yy mode
X-Git-Tag: v4.22~134
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=48feeb3723d8d5e6230f447a4b8fd5f0a6fef164;p=strace

printfd: print character/block device number in -yy mode

* util.c: Include <sys/stat.h>, <sys/sysmacros.h>,
and "largefile_wrappers.h".
(printsocket, printdev): New functions.
(printfd): Move socket matching/printing logic to printsocket.  Check
also for printdev.  Escape opening angle bracket in addition to closing angle
bracket as it can show up as a separator in printdev.
* tests/fsync-y.c: Update expected output.
* strace.1.in: Mention this.
* NEWS: Likewise.

Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
---

diff --git a/NEWS b/NEWS
index cd85c097..c0874912 100644
--- a/NEWS
+++ b/NEWS
@@ -5,7 +5,7 @@ Noteworthy changes in release ?.?? (????-??-??)
   * The mailing list was moved to strace-devel@lists.strace.io.
 
 * Changes in behaviour
-  * Closing angle bracket is now printed as an octal number escape sequence
+  * Angle brackets are now printed as octal number escape sequences
     in the output of paths associated with file descriptors.
 
 * Improvements
@@ -14,6 +14,7 @@ Noteworthy changes in release ?.?? (????-??-??)
   * Enhanced NETLINK_ROUTE protocol decoding.
   * Updated lists of signal codes.
   * Updated lists of INET_DIAG_BC_*, POLL*, RWF_*, and SCHED_FLAG_* constants.
+  * Implemented block/character device number printing in -yy mode.
 
 * Bug fixes
   * Fixed build on m68k.
diff --git a/strace.1.in b/strace.1.in
index d05d1650..3443b3b9 100644
--- a/strace.1.in
+++ b/strace.1.in
@@ -318,7 +318,8 @@ Print all strings in hexadecimal string format.
 Print paths associated with file descriptor arguments.
 .TP
 .B \-yy
-Print protocol specific information associated with socket file descriptors.
+Print protocol specific information associated with socket file descriptors,
+and block/character device number associated with device file descriptors.
 .SS Statistics
 .TP 12
 .B \-c
diff --git a/tests/fsync-y.c b/tests/fsync-y.c
index df4b1088..34267b9c 100644
--- a/tests/fsync-y.c
+++ b/tests/fsync-y.c
@@ -46,7 +46,7 @@ main(void)
 	} checks[] = {
 		{ ARG_STR("\1\0020\v\0047\f\58\t\79\n\10\0171\r\0167\218\37 \\\'\"<<0::0>>1~\177\200\377"),
 			"\\1\\0020\\v\\0047\\f\\58\\t\\79\\n\\10\\0171\\r\\0167"
-			"\\218\\37 \\\\\'\\\"<<0::0\\76\\0761~\\177\\200\\377" },
+			"\\218\\37 \\\\\'\\\"\\74\\0740::0\\76\\0761~\\177\\200\\377" },
 	};
 
 	if (!getcwd(dir, sizeof(dir)))
@@ -60,7 +60,7 @@ main(void)
 		int rc = fsync(fd);
 
 		printf("fsync(%ld<", fd);
-		print_quoted_string_ex(dir, false, ">");
+		print_quoted_string_ex(dir, false, ">:");
 		printf("/%s>) = %s\n", checks[i].fdstr, sprintrc(rc));
 
 		close(fd);
diff --git a/util.c b/util.c
index 78aad90b..38458658 100644
--- a/util.c
+++ b/util.c
@@ -36,10 +36,14 @@
 #include <limits.h>
 #include <fcntl.h>
 #include <stdarg.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
 #ifdef HAVE_SYS_XATTR_H
 # include <sys/xattr.h>
 #endif
 #include <sys/uio.h>
+
+#include "largefile_wrappers.h"
 #include "xstring.h"
 
 int
@@ -418,24 +422,59 @@ getfdinode(struct tcb *tcp, int fd)
 	return 0;
 }
 
+static bool
+printsocket(struct tcb *tcp, int fd, const char *path)
+{
+	const char *str = STR_STRIP_PREFIX(path, "socket:[");
+	size_t len;
+	unsigned long inode;
+
+	return (str != path)
+		&& (len = strlen(str))
+		&& (str[len - 1] == ']')
+		&& (inode = strtoul(str, NULL, 10))
+		&& print_sockaddr_by_inode(tcp, fd, inode);
+}
+
+static bool
+printdev(struct tcb *tcp, int fd, const char *path)
+{
+	struct_stat st;
+
+	if (path[0] != '/')
+		return false;
+
+	if (stat_file(path, &st)) {
+		debug_func_perror_msg("stat(\"%s\")", path);
+		return false;
+	}
+
+	switch (st.st_mode & S_IFMT) {
+	case S_IFBLK:
+	case S_IFCHR:
+		print_quoted_string_ex(path, strlen(path),
+				       QUOTE_OMIT_LEADING_TRAILING_QUOTES,
+				       "<>");
+		tprintf("<%s %u:%u>",
+			S_ISBLK(st.st_mode)? "block" : "char",
+			major(st.st_rdev), minor(st.st_rdev));
+		return true;
+	}
+
+	return false;
+}
+
 void
 printfd(struct tcb *tcp, int fd)
 {
 	char path[PATH_MAX + 1];
 	if (show_fd_path && getfdpath(tcp, fd, path, sizeof(path)) >= 0) {
-		const char *str;
-		size_t len;
-		unsigned long inode;
-
 		tprintf("%d<", fd);
 		if (show_fd_path <= 1
-		    || (str = STR_STRIP_PREFIX(path, "socket:[")) == path
-		    || !(len = strlen(str))
-		    || str[len - 1] != ']'
-		    || !(inode = strtoul(str, NULL, 10))
-		    || !print_sockaddr_by_inode(tcp, fd, inode)) {
+		    || (!printsocket(tcp, fd, path)
+		         && !printdev(tcp, fd, path))) {
 			print_quoted_string_ex(path, strlen(path),
-				QUOTE_OMIT_LEADING_TRAILING_QUOTES, ">");
+				QUOTE_OMIT_LEADING_TRAILING_QUOTES, "<>");
 		}
 		tprints(">");
 	} else