2007-08-14 David Smith <dsmith@redhat.com>

	Merge from setuid-branch.  Changes also by Martin Hunt
	<hunt@redhat.com>.

	* staprun.c (init_staprun): Drop CAP_SYS_ADMIN when we're done
	with it.
	(main): Calls parse_modpath instead of path_parse_modname.  Just
	call parse_modpath with argv[optind]. Let it allocate and set
	modpath and modname.  If no modulename was given, display usage
	and exit.  Drop CAP_SYS_NICE when we're done with it.  Set
	atexit(exit_cleanup) so cleanup always gets called and modules get
	removed.  Call handle_symbols.
	(run_stapio): Set argv[0] to stapio so that it executes as itself
	instead of staprun.
	(cleanup): Only do cleanups once and only try to remove module
	when appropriate.
	(exit_cleanup): New. Calls cleanup().
	(mountfs): Sets uid to root before making directory and then
	restores uid.
	(setup_ctl_channel): Uses DEBUGFS define and improved
	error message.
	(setup_relayfs): Ditto.
	(setup_oldrelayfs): Uses DEBUGFS and RELAYFS defines.
	(run_stp_check): Replaced by mountfs().
	(mountfs): New function.  Replaces an external script with C code.
	(init_staprun): Calls mountfs() instead of run_stp_check().

	* staprun.h: Renamed path_parse_modname to parse_modpath.  Added
	MODULE_NAME_LEN define.  Added [_][p]err macros.  Removed
	VERSION_CMD.

	* mainloop.c (cleanup_and_exit): Make sure initialized is 2
	before exiting with code 2.
	(stp_main_loop): Set initialized to 2 when STP_TRANSPORT
	is received. Call cleanup_and_exit() with proper status.
	(start_cmd): exit 1 instead of -1.
	(system_cmd): Ditto.
	(init_staprun): Renamed init_stapio.
	(cleanup_and_exit): Set exit status.

	* cap.c: New file.
	* common.c: New file.
	* stapio.c: New file.
	* staprun_funcs.c: New file.
	* Makefile: Removed.

	* symbols.c (get_sections): Move the filter code up so that
	uninteresting section names are filtered out before
	attempting to open them.
	(do_kernel_symbols): Better detect overfow conditions and realloc
	new space.
	(do_module): After sending all modules, send a null message to
	indicate we are finished.

	* ctl.c (init_ctl_channel): When attempting to attach, if the
	control channel doesn't exist, print a better error message.

	* relay_old.c (init_oldrelayfs): Errors out if
	open_relayfs_files() couldn't open any files.

	PR 4795
	* mainloop.c (send_request): Fixed buffer overflow check.
	* staprun.h: Added buffer overflow checking versions of
	strcpy/sprintf/snprintf.
	* common.c (path_parse_modname): Checks for overflows on
	strcpy/sprintf/snprintf.
	(read_buffer_info): Ditto.
	* ctl.c (init_ctl_channel): Ditto.
	* relay.c (init_relayfs): Ditto.
	* relay_old.c (open_relayfs_files): Ditto.
	(init_oldrelayfs): Ditto.
	* staprun_funcs.c (insert_module): Ditto.
	(check_path): Ditto.
	* symbols.c (get_sections): Ditto.

1 files changed, 96 insertions, 13 deletions

diff --git a/runtime/staprun/staprun.h b/runtime/staprun/staprun.h
index f8fcfe66..cde44922 100644
--- a/runtime/staprun/staprun.h
+++ b/runtime/staprun/staprun.h
@@ -1,6 +1,6 @@
 /* -*- linux-c -*-
  *
- * staprun.h - include file for staprun
+ * staprun.h - include file for staprun and stapio
  *
  * This file is part of systemtap, and is free software.  You can
  * redistribute it and/or modify it under the terms of the GNU General
@@ -33,32 +33,93 @@
 #include <sys/wait.h>
 #include <sys/statfs.h>
 #include <linux/version.h>
+#include <sys/capability.h>
 
 #define DEBUG
 #ifdef DEBUG
-#define dbug(level, args...) {if (verbose>=level) {fprintf(stderr,"%s:%d ",__FUNCTION__, __LINE__); fprintf(stderr,args);}}
+#define dbug(level, args...) {if (verbose>=level) {fprintf(stderr,"%s:%s:%d ",__name__,__FUNCTION__, __LINE__); fprintf(stderr,args);}}
 #else
 #define dbug(level, args...) ;
 #endif /* DEBUG */
 
-#define err(args...) {fprintf(stderr,"%s:%d ",__FUNCTION__, __LINE__); fprintf(stderr,args); }
+extern char *__name__;
+
+/* print to stderr */
+#define err(args...) fprintf(stderr,args)
+
+/* better perror() */
+#define perr(args...) do {					\
+		int _errno = errno;				\
+		fputs("ERROR: ", stderr);			\
+		fprintf(stderr, args);				\
+		fprintf(stderr, ": %s\n", strerror(_errno));	\
+	} while (0)
+
+/* Error messages. Use these for serious errors, not informational messages to stderr. */
+#define _err(args...) do {fprintf(stderr,"%s:%s:%d: ERROR: ",__name__, __FUNCTION__, __LINE__); fprintf(stderr,args);} while(0)
+#define _perr(args...) do {					\
+		int _errno = errno;				\
+		_err(args);					\
+		fprintf(stderr, ": %s\n", strerror(_errno));	\
+	} while (0)
+#define overflow_error() _err("Internal buffer overflow. Please file a bug report.\n")
+		
+#define do_cap(cap,func,args...) ({			\
+			int _rc, _saved_errno;		\
+			add_cap(cap);			\
+			_rc = func(args);		\
+			_saved_errno = errno;		\
+			del_cap(cap);			\
+			errno = _saved_errno;		\
+			_rc;				\
+		})					\
+
+
+/* Error checking version of sprintf() - returns 1 if overflow error */
+#define sprintf_chk(str, args...) ({			\
+	int _rc;					\
+	_rc = snprintf(str, sizeof(str), args);		\
+	if (_rc >= (int)sizeof(str)) {			\
+		overflow_error();			\
+		_rc = 1;				\
+	}						\
+	else						\
+		_rc = 0;				\
+	_rc;						\
+})
+
+/* Error checking version of snprintf() - returns 1 if overflow error */
+#define snprintf_chk(str, size, args...) ({		\
+	int _rc;					\
+	_rc = snprintf(str, size, args);		\
+	if (_rc >= (int)size) {				\
+		overflow_error();			\
+		_rc = 1;				\
+	}						\
+	else						\
+		_rc = 0;				\
+	_rc;						\
+})
+
+/* Grabbed from linux/module.h kernel include. */
+#define MODULE_NAME_LEN (64 - sizeof(unsigned long))
 
 /* we define this so we are compatible with old transport, but we don't have to use it. */
 #define STP_OLD_TRANSPORT
 #include "../transport/transport_msgs.h"
 
-/* command to check system's kernel version */
-/* KERNEL_VERSION(2.6.15) = 132623 */
-#define VERSION_CMD "uname -r | awk \'{split($1,a,\".\"); split(a[3],b,\"-\"); exit (a[1]*65536+a[2]*256+b[1] <= 132623)}\'"
 extern int use_old_transport;
 
-#define RELAYFS_MAGIC			0xF0B4A981
-#define DEBUGFS_MAGIC			0x64626720
+#define RELAYFS_MAGIC	0xF0B4A981
+#define DEBUGFS_MAGIC	0x64626720
+#define DEBUGFSDIR	"/sys/kernel/debug"
+#define RELAYFSDIR	"/mnt/relay"
 
 /*
  * function prototypes
  */
 int init_staprun(void);
+int init_stapio(void);
 int stp_main_loop(void);
 int send_request(int type, void *data, int len);
 void cleanup_and_exit (int);
@@ -71,28 +132,50 @@ void close_relayfs(void);
 int init_oldrelayfs(void);
 void close_oldrelayfs(int);
 void setup_signals(void);
+/* cap.c */
+void print_cap(char *text);
+int init_cap(void);
+void add_cap(cap_value_t cap);
+void del_cap(cap_value_t cap);
+void drop_cap(cap_value_t cap);
+/* staprun_funcs.c */
+void setup_staprun_signals(void);
+const char *moderror(int err);
+int insert_module(void);
+int mountfs(void);
+int check_permissions(void);
+void handle_symbols(void);
+
+/* common.c functions */
+void parse_args(int argc, char **argv);
+void usage(char *prog);
+void parse_modpath(const char *);
+void setup_signals(void);
 
 /*
  * variables 
  */
 extern int control_channel;
 extern int ncpus;
+extern int initialized;
 
 /* flags */
 extern int verbose;
 extern unsigned int buffer_size;
-extern char modname[];
+extern char *modname;
 extern char *modpath;
-extern char *modoptions[];
+#define MAXMODOPTIONS 64
+extern char *modoptions[MAXMODOPTIONS];
 extern int target_pid;
 extern char *target_cmd;
 extern char *outfile_name;
 extern int attach_mod;
 extern int load_only;
 
-/* uid/gid to use when execing external programs */
-extern uid_t cmd_uid;
-extern gid_t cmd_gid;
+/* getopt variables */
+extern char *optarg;
+extern int optopt;
+extern int optind;
 
 /* maximum number of CPUs we can handle */
 #define NR_CPUS 256