Version 0.2.1

* Added -u option (run command as other username)
* Updated manual page a bit

7 files changed, 94 insertions, 90 deletions

diff --git a/KK b/KK
deleted file mode 100644
index db0a403..0000000
--- a/KK
+++ /dev/null
@@ -1,79 +0,0 @@
-atexit(0x40006150)                                = 0
-__libc_init_first(2, 0xbffffb6e, 0xbffffb7d, 0, 0xbffffb82) = 0x40006150
-atexit(0x0804cc20)                                = 0
-socket(2, 2, 0, 0x0804a0d5, 0x4000b070)           = 5
-socket(4, 2, 0, 2, 2)                             = -1
-socket(3, 2, 0, 4, 2)                             = -1
-socket(5, 2, 0, 0x0804a0d5, 0x4000b070)           = -1
-strncpy(0xbffff9b4, "eth0", 16)                   = 0xbffff9b4
-memset(0xbffff828, '\000', 340)                   = 0xbffff828
-strcpy(0xbffff828, "eth0")                        = 0xbffff828
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-ioctl(5, 35091, 0xbffff7e8, 0xbffff7e8, 0xbffff9b4) = 0
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-ioctl(5, 35111, 0xbffff7e8, 0xbffff7e8, 0xbffff9b4) = 0
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-ioctl(5, 35101, 0xbffff7e8, 0xbffff7e8, 0xbffff9b4) = 0
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-ioctl(5, 35105, 0xbffff7e8, 0xbffff7e8, 0xbffff9b4) = 0
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-ioctl(5, 35184, 0xbffff7e8, 0xbffff7e8, 0xbffff9b4) = 0
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-ioctl(5, 35184, 0xbffff7e8, 0xbffff7e8, 0xbffff9b4) = 0
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-ioctl(5, 35095, 0xbffff7e8, 0xbffff9b4, 0xbffff828) = 0
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-ioctl(5, 35097, 0xbffff7e8, 0xbffff9b4, 0xbffff828) = 0
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-ioctl(5, 35099, 0xbffff7e8, 0xbffff9b4, 0xbffff828) = 0
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-ioctl(5, 35093, 0xbffff7e8, 0xbffff9b4, 0xbffff828) = 0
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-strcpy(0xbffff7e8, "eth0")                        = 0xbffff7e8
-fopen(0x0804cfe0, 0x0804cfde, 0xbffff7e8, 0xbffff828, 0xbffff9b4) = 0x0804f828
-fgets("Inter-|   Receive               "..., 255, 0x0804f828) = 0xbffff6d0
-fgets(" face |packets errs drop fifo fr"..., 255, 0x0804f828) = 0xbffff6d0
-strstr(" face |packets errs drop fifo fr"..., "bytes") = NULL
-fgets("    lo:     26    0    0    0   "..., 255, 0x0804f828) = 0xbffff6d0
-strncmp("lo:     26    0    0    0    0  "..., "eth0", 4) = 7
-fgets("  lo:0:      0    0    0    0   "..., 255, 0x0804f828) = 0xbffff6d0
-strncmp("lo:0:      0    0    0    0    0"..., "eth0", 4) = 7
-fgets("  eth0:      0    0    0    0   "..., 255, 0x0804f828) = 0xbffff6d0
-strncmp("eth0:      0    0    0    0    0"..., "eth0", 4) = 0
-strchr(0xbffff6d2, 58, 0xbffff7e8, 0xbffff828, 0xbffff9b4) = 0xbffff6d6
-strchr(0xbffff6d7, 58, 0xbffff7e8, 0xbffff828, 0xbffff9b4) = 0
-strncmp("0    0    0    0    0        0  "..., "No", 2) = -30
-sscanf(0xbffff6dd, 0x0804d02b, 0xbffff924, 0xbffff934, 0xbffff93c) = 11
-fclose(0x0804f828)                                = 0
-strncmp("eth0", "lo", 2)                          = -7
-printf("%-8.8s  Link encap:%s  ")                 = 31
-sprintf(0x0804f240, 0x0804d740, 0, 80, 78)        = 17
-printf("HWaddr %s  ")                             = 26
-printf("\n")                                      = 1
-inet_ntoa(0x010010ac, 0x0804ed64, 0xbffff828, 0x0804ef2c, 1) = 0x0804f828
-strcpy(0x0804f5d4, "172.16.0.1")                  = 0x0804f5d4
-printf("          %s addr:%s")                    = 30
-inet_ntoa(0xff0010ac, 0x0804ed64, 0xbffff828, 0x0804ef2c, 1) = 0x0804f828
-strcpy(0x0804f5d4, "172.16.0.255")                = 0x0804f5d4
-printf("  Bcast:%s  ")                            = 22
-inet_ntoa(0x00ffffff, 0x0804ed64, 0xbffff828, 0x0804ef2c, 1) = 0x0804f828
-strcpy(0x0804f5d4, "255.255.255.0")               = 0x0804f5d4
-printf("Mask:%s\n")                               = 19
-printf("          ")                              = 10
-printf("UP ")                                     = 3
-printf("BROADCAST ")                              = 10
-printf("RUNNING ")                                = 8
-printf("MULTICAST ")                              = 10
-printf(" MTU:%d  Metric:%d\n")                    = 20
-printf("          ")                              = 10
-printf("RX packets:%lu error:%lu dropped"...)     = 46
-printf("          ")                              = 10
-printf("TX packets:%lu error:%lu dropped"...)     = 58
-printf("          ")                              = 10
-printf("Interrupt:%d ")                           = 12
-printf("Base address:0x%x ")                      = 19
-printf("\n")                                      = 1
-printf("\n")                                      = 1
-close(5)                                          = 0
-exit(0)
-+++ exited (status 0) +++
diff --git a/TODO b/TODO
index e4d947a..150efce 100644
--- a/TODO
+++ b/TODO
@@ -1,5 +1,6 @@
 * Option -p (trace running process)
 * Option -f (trace children)
+* Option -u (run command as username handling setuid and/or setgid)
 * SYSCALLS:
   + execve()		<- trace new program
 * Display different argument types:
@@ -9,4 +10,4 @@
 * SPARC:
   + almost all...
 * netscape:
-  + Why does it shows so many `breakpointed at:' messages?
+  + Why does it show so many `breakpointed at:' messages?
diff --git a/debian/changelog b/debian/changelog
index 340ca18..d405191 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+ltrace (0.2.1) unstable; urgency=low
+
+  * Added -u option (run command as other username)
+  * Updated manual page a bit
+
+ -- Juan Cespedes <cespedes@debian.org>  Tue, 10 Mar 1998 00:08:38 +0100
+
 ltrace (0.2.0) unstable; urgency=low
 
   * First `unstable' release
diff --git a/execute_program.c b/execute_program.c
index 02d6471..d451f7b 100644
--- a/execute_program.c
+++ b/execute_program.c
@@ -1,13 +1,19 @@
 #include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
 #include <unistd.h>
 #include <errno.h>
 #include <string.h>
+#include <pwd.h>
+#include <grp.h>
 
 #include "ltrace.h"
 #include "options.h"
 #include "output.h"
 #include "sysdep.h"
 
+static void change_uid(struct process * proc);
+
 void execute_program(struct process * sp, char **argv)
 {
 	int pid;
@@ -21,6 +27,7 @@ void execute_program(struct process * sp, char **argv)
 		perror("fork");
 		exit(1);
 	} else if (!pid) {	/* child */
+		change_uid(sp);
 		trace_me();
 		execvp(sp->filename, argv);
 		fprintf(stderr, "Can't execute `%s': %s\n", sp->filename, strerror(errno));
@@ -35,3 +42,54 @@ void execute_program(struct process * sp, char **argv)
 
 	return;
 }
+
+static void change_uid(struct process * proc)
+{
+	uid_t run_uid, run_euid;
+	gid_t run_gid, run_egid;
+
+	if (opt_u) {
+		struct passwd *pent;
+
+		if (getuid() != 0 || geteuid() != 0) {
+			fprintf(stderr, "you must be root to use the -u option\n");
+			exit(1);
+		}
+		if ((pent = getpwnam(opt_u)) == NULL) {
+			fprintf(stderr, "cannot find user `%s'\n", opt_u);
+			exit(1);
+		}
+		run_uid = pent->pw_uid;
+		run_gid = pent->pw_gid;
+
+		if (initgroups(opt_u, run_gid) < 0) {
+			perror("initgroups");
+			exit(1);
+		}
+	} else {
+		run_uid = getuid();
+		run_gid = getgid();
+	}
+	if (opt_u || !geteuid()) {
+		struct stat statbuf;
+		run_euid = run_uid;
+		run_egid = run_gid;
+
+		if (!stat(proc->filename, &statbuf)) {
+			if (statbuf.st_mode & S_ISUID) {
+				run_euid = statbuf.st_uid;
+			}
+			if (statbuf.st_mode & S_ISGID) {
+				run_euid = statbuf.st_gid;
+			}
+		}
+		if (setregid(run_gid, run_egid) < 0) {
+			perror("setregid");
+			exit(1);
+		}
+		if (setreuid(run_uid, run_euid) < 0) {
+			perror("setreuid");
+			exit(1);
+		}
+	}
+}
diff --git a/ltrace.1 b/ltrace.1
index 0d41e28..c5ba623 100644
--- a/ltrace.1
+++ b/ltrace.1
@@ -6,7 +6,7 @@ ltrace \- A library call tracer
 
 .SH SYNOPSIS
 .B ltrace
-.I "[-diLS] [-a column] [-s strsize] [-o filename] command [arg ...]"
+.I "[-difLS] [-a column] [-s strsize] [-o filename] [-u username] [-p pid] ... [command [arg ...]]"
 
 .SH DESCRIPTION
 .B ltrace
@@ -21,23 +21,18 @@ Its use is very similar to
 
 .SH OPTIONS
 .TP
-.I \-a column
-Align return values in a secific column (default column 50).
 .I \-d
 Increase the debugging level.
 .TP
+.I \-i
+Print the instruction pointer at the time of the library call.
+.TP
 .I \-f
 Trace child processes as they are created by
 currently  traced processes as a result of the fork(2)
 or clone(2) system calls.
 The new process is attached as soon as its pid is known.
 .TP
-.I \-i
-Print the instruction pointer at the time of the library call.
-.TP
-.I \-s
-Specify the maximum string size to print (the default is 32).
-.TP
 .I \-L
 DON'T display library calls (use it with the
 .I \-S
@@ -46,10 +41,27 @@ option).
 .I \-S
 Display system calls as well as library calls
 .TP
+.I \-a column
+Align return values in a secific column (default column 50).
+.TP
+.I \-s
+Specify the maximum string size to print (the default is 32).
+.TP
 .I \-o filename
 Write the trace output to the file
 .I filename
 rather than to stderr.
+.TP
+.I \-u username
+Run command with the userid, groupid and supplementary groups of
+.IR username .
+This option is only useful when running as root and enables the
+correct execution of setuid and/or setgid binaries.
+.TP
+.I \-p pid
+Attach to the process with the process ID
+.I pid
+and begin tracing.
 
 .SH BUGS
 At the moment, there are too many bugs to list here.
diff --git a/options.c b/options.c
index f5b8874..66efc37 100644
--- a/options.c
+++ b/options.c
@@ -16,6 +16,7 @@ int opt_s = DEFAULT_STRLEN;	/* default maximum # of bytes printed in strings */
 int opt_S = 0;			/* display syscalls */
 int opt_L = 1;			/* display library calls */
 int opt_f = 0;			/* trace child processes as they are created */
+char * opt_u = NULL;		/* username to run command as */
 
 /* List of pids given to option -p: */
 struct opt_p_t * opt_p = NULL;	/* attach to process with a given pid */
@@ -23,7 +24,7 @@ struct opt_p_t * opt_p = NULL;	/* attach to process with a given pid */
 static void usage(void)
 {
 	fprintf(stderr, "Usage: ltrace [-dfiLS] [-a column] [-s strlen] [-o filename]\n"
-			"              [-p pid] ... [command [arg ...]]\n\n");
+			"              [-u username] [-p pid] ... [command [arg ...]]\n\n");
 }
 
 static char * search_for_command(char * filename)
@@ -92,6 +93,9 @@ char ** process_options(int argc, char **argv)
 					break;
 			case 'f':	opt_f = 1;
 					break;
+			case 'u':	opt_u = argv[1];
+					argc--; argv++;
+					break;
 			case 'p':
 				{
 					struct opt_p_t * tmp = malloc(sizeof(struct opt_p_t));
diff --git a/options.h b/options.h
index 311a13b..da17154 100644
--- a/options.h
+++ b/options.h
@@ -8,6 +8,7 @@ extern int opt_s;	/* default maximum # of bytes printed in strings */
 extern int opt_L;	/* display library calls */
 extern int opt_S;	/* display system calls */
 extern int opt_f;	/* trace child processes */
+extern char * opt_u;	/* username to run command as */
 
 struct opt_p_t {
 	pid_t pid;