1#!/usr/bin/perl
2#
3# errinfo - report on syscall failures and print errno error messages.
4#	    Written using Perl and DTrace (Solaris 10 03/05)
5#
6# When system calls fail, an errno variable is set to convay a meaningful
7# message to the end user - so long as the program does something with it
8# (eg, "ls" printing "No such file or directory"). This program fetches
9# and prints details for all syscall failures along with their message,
10# whether the failing program is already printing this info or not.
11#
12# 20-Apr-2006, ver 0.83
13#
14# USAGE:	errinfo [-ch] [-p PID] [-n name]
15#
16#		-c		# counts - aggregate style
17#		-p PID		# examine this PID only
18#		-n name		# examine processes with this name only
19#	eg,
20#		errinfo			# default output - snoop event style
21#		errinfo -n ssh		# examine "ssh" processes only
22#		errinfo -cn ssh		# examine "ssh" using counts
23#
24# FIELDS:
25#		EXEC		Program name (truncated)
26#		SYSCALL		System call name
27#		ERR		Value of errno
28#		DESC		Description of errno message
29#
30# SEE ALSO:	/usr/include/sys/errno.h
31#
32# COPYRIGHT: Copyright (c) 2005, 2006 Brendan Gregg.
33#
34# CDDL HEADER START
35#
36#  The contents of this file are subject to the terms of the
37#  Common Development and Distribution License, Version 1.0 only
38#  (the "License").  You may not use this file except in compliance
39#  with the License.
40#
41#  You can obtain a copy of the license at Docs/cddl1.txt
42#  or http://www.opensolaris.org/os/licensing.
43#  See the License for the specific language governing permissions
44#  and limitations under the License.
45#
46# CDDL HEADER END
47#
48# Author: Brendan Gregg  [Sydney, Australia]
49#
50# 18-Apr-2005   Brendan Gregg   Created this.
51#
52
53use Getopt::Std;
54
55#
56#  Defaults
57#
58$FILTER = "";
59$COUNT = 0;
60
61#
62#  Command line arguments
63#
64&Usage() if $ARGV[0] eq "--help";
65getopts('ch:n:p:') || &Usage();
66&Usage() if $opt_h;
67$COUNT = 1 if $opt_c;
68$FILTER = "&& (execname == strstr(execname,\"$opt_n\")) || (\"$opt_n\" == strstr(\"$opt_n\",execname))" if defined $opt_n;
69$FILTER = "&& pid == $opt_p" if defined $opt_p;
70
71#
72# Find the MacOSX SDK path
73#
74$sdk_path = `xcrun --sdk macosx --show-sdk-path` or die "ERROR: trying to find the MacOSX SDK path: $?\n";
75chomp($sdk_path);
76
77#
78#  Load errno descriptions
79#
80open(ERRNO, "$sdk_path/usr/include/sys/errno.h") || die "ERROR1: reading errno.h: $!\n";
81while (chomp($line = <ERRNO>)) {
82	next unless $line =~ /^#define/;
83	($errno,$desc) = $line =~ /^#define\s+\S+\s+(\d+)\s+\/\*(.*)\*\//;
84	$Errno{$errno} = $desc;
85}
86close ERRNO;
87
88#
89#  Declare DTrace script
90#
91 if ($COUNT) {		# aggregate style
92$dtrace = <<END;
93/usr/sbin/dtrace -n '
94	#pragma D option quiet
95	syscall:::return 
96	/errno != 0 && pid != \$pid $FILTER/ 
97	{ 
98		\@Errs[execname, probefunc, errno] = count(); 
99	}
100	dtrace:::END {
101		printa("%s %s %d %\@d\\n", \@Errs);
102	}'
103END
104 } else {		# snoop style
105$dtrace = <<END; 
106/usr/sbin/dtrace -n '
107	#pragma D option quiet
108	#pragma D option switchrate=5hz
109	syscall:::return 
110	/errno != 0 && pid != \$pid $FILTER/ 
111	{ 
112		printf("%s %s %d\\n", execname, probefunc, errno); 
113	}'
114END
115 }
116
117#
118#  Cleanup on signals
119#
120$SIG{INT} = \&Cleanup_Signal;    # Ctrl-C
121$SIG{QUIT} = \&Cleanup_Signal;   # Ctrl-\
122$SIG{TERM} = \&Cleanup_Signal;   # TERM
123
124#
125#  Run DTrace, process output
126#
127
128if ($COUNT) {
129	print STDERR "Tracing... Hit Ctrl-C to end.\n";
130	$header = 1;
131} else {
132	printf("%16s %16s %4s  %s\n","EXEC","SYSCALL","ERR","DESC");
133}
134
135### Open DTrace
136open(DTRACE,"$dtrace |") || die "ERROR2: Can't start dtrace (perms?): $!\n";
137
138### Process DTrace output
139while (chomp($line = <DTRACE>)) {
140
141	### Print count header
142	if ($COUNT && $header) {
143		printf("\n%16s %16s %4s %6s  %s\n",
144		 "EXEC","SYSCALL","ERR","COUNT","DESC");
145		$header = 0;
146	}
147
148	### Split data
149	($execname,$syscall,$errno,$counts) = split(' ',$line);
150	next if $errno eq "";
151
152	### Fetch errno description
153	$desc = $Errno{$errno};
154
155	### Print output line
156	if ($COUNT) {
157		printf("%16s %16s %4d %6d %s\n",
158		 $execname,$syscall,$errno,$counts,$desc);
159	} else {
160		printf("%16s %16s %4d %s\n",$execname,$syscall,$errno,$desc);
161	}
162}
163close(DTRACE);
164
165#
166#  Triggered by signals
167#
168sub Cleanup_Signal {
169}
170
171#
172#  Usage message
173#
174sub Usage {
175        print STDERR "USAGE: errinfo [-ch] [-p PID] [-n name]\n";
176	print STDERR <<ENDUSAGE;
177     eg,
178       errinfo       # default output - snoop event style
179          -c         # counts - aggregate style
180          -p 871     # examine PID 871 only
181          -n ssh     # examine processes with the name "ssh" only
182          -cn ssh    # examine "ssh" using counts
183ENDUSAGE
184        exit(1);
185}
186