xenstore: Make code more secure

diff -r 2d761ca771fb tools/xenstore/xenstored_core.c
@@ -685,7 +685,7 @@ static char *perms_to_strings(const void
 	char buffer[MAX_STRLEN(unsigned int) + 1];
 
 	for (*len = 0, i = 0; i < num; i++) {
-		if (!xs_perm_to_string(&perms[i], buffer))
+		if (!xs_perm_to_string(&perms[i], buffer, sizeof(buffer)))
 			return NULL;
 
 		strings = talloc_realloc(ctx, strings, char,

@@ -1659,7 +1659,7 @@ static void write_pidfile(const char *pi
 	if (lockf(fd, F_TLOCK, 0) == -1)
 		exit(0);
 
-	len = sprintf(buf, "%ld\n", (long)getpid());
+	len = snprintf(buf, sizeof(buf), "%ld\n", (long)getpid());
 	if (write(fd, buf, len) != len)
 		barf_perror("Writing pid file %s", pidfile);
 }

diff -r 2d761ca771fb tools/xenstore/xenstored_transaction.c
@@ -181,7 +181,7 @@ void do_transaction_start(struct connect
 	talloc_set_destructor(trans, destroy_transaction);
 	conn->transaction_started++;
 
-	sprintf(id_str, "%u", trans->id);
+	snprintf(id_str, sizeof(id_str), "%u", trans->id);
 	send_reply(conn, XS_TRANSACTION_START, id_str, strlen(id_str)+1);
 }
 

diff -r 2d761ca771fb tools/xenstore/xs.c
@@ -20,6 +20,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#include <sys/uio.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <string.h>

@@ -519,7 +520,7 @@ bool xs_set_permissions(struct xs_handle
 	for (i = 0; i < num_perms; i++) {
 		char buffer[MAX_STRLEN(unsigned int)+1];
 
-		if (!xs_perm_to_string(&perms[i], buffer))
+		if (!xs_perm_to_string(&perms[i], buffer, sizeof(buffer)))
 			goto unwind;
 
 		iov[i+1].iov_base = strdup(buffer);

@@ -687,9 +688,9 @@ bool xs_introduce_domain(struct xs_handl
 	char eventchn_str[MAX_STRLEN(eventchn)];
 	struct iovec iov[3];
 
-	sprintf(domid_str, "%u", domid);
-	sprintf(mfn_str, "%lu", mfn);
-	sprintf(eventchn_str, "%u", eventchn);
+	snprintf(domid_str, sizeof(domid_str), "%u", domid);
+	snprintf(mfn_str, sizeof(mfn_str), "%lu", mfn);
+	snprintf(eventchn_str, sizeof(eventchn_str), "%u", eventchn);
 
 	iov[0].iov_base = domid_str;
 	iov[0].iov_len = strlen(domid_str) + 1;

@@ -708,7 +709,7 @@ static void * single_with_domid(struct x
 {
 	char domid_str[MAX_STRLEN(domid)];
 
-	sprintf(domid_str, "%u", domid);
+	snprintf(domid_str, sizeof(domid_str), "%u", domid);
 
 	return xs_single(h, XBT_NULL, type, domid_str, NULL);
 }

@@ -728,7 +729,7 @@ char *xs_get_domain_path(struct xs_handl
 {
 	char domid_str[MAX_STRLEN(domid)];
 
-	sprintf(domid_str, "%u", domid);
+	snprintf(domid_str, sizeof(domid_str), "%u", domid);
 
 	return xs_single(h, XBT_NULL, XS_GET_DOMAIN_PATH, domid_str, NULL);
 }

diff -r 2d761ca771fb tools/xenstore/xs_lib.c
@@ -17,12 +17,12 @@
     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
-#include "xs_lib.h"
 #include <unistd.h>
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
+#include "xs_lib.h"
 
 /* Common routines for the Xen store daemon and client library. */
 

@@ -53,7 +53,7 @@ const char *xs_daemon_tdb(void)
 const char *xs_daemon_tdb(void)
 {
 	static char buf[PATH_MAX];
-	sprintf(buf, "%s/tdb", xs_daemon_rootdir());
+	snprintf(buf, sizeof(buf), "%s/tdb", xs_daemon_rootdir());
 	return buf;
 }
 

@@ -143,7 +143,8 @@ bool xs_strings_to_perms(struct xs_permi
 }
 
 /* Convert permissions to a string (up to len MAX_STRLEN(unsigned int)+1). */
-bool xs_perm_to_string(const struct xs_permissions *perm, char *buffer)
+bool xs_perm_to_string(const struct xs_permissions *perm,
+                       char *buffer, size_t buf_len)
 {
 	switch (perm->perms) {
 	case XS_PERM_WRITE:

@@ -162,7 +163,7 @@ bool xs_perm_to_string(const struct xs_p
 		errno = EINVAL;
 		return false;
 	}
-	sprintf(buffer+1, "%i", (int)perm->id);
+	snprintf(buffer+1, buf_len-1, "%i", (int)perm->id);
 	return true;
 }
 

diff -r 2d761ca771fb tools/xenstore/xs_lib.h
@@ -61,7 +61,8 @@ bool xs_strings_to_perms(struct xs_permi
 			 const char *strings);
 
 /* Convert permissions to a string (up to len MAX_STRLEN(unsigned int)+1). */
-bool xs_perm_to_string(const struct xs_permissions *perm, char *buffer);
+bool xs_perm_to_string(const struct xs_permissions *perm,
+                       char *buffer, size_t buf_len);
 
 /* Given a string and a length, count how many strings (nul terms). */
 unsigned int xs_count_strings(const char *strings, unsigned int len);

diff -r 2d761ca771fb tools/xenstore/xsls.c
@@ -87,7 +87,7 @@ void print_dir(struct xs_handle *h, char
                 for (i = 0; i < nperms; i++) {
                     if (i)
                         putchar(',');
-                    xs_perm_to_string(perms+i, buf);
+                    xs_perm_to_string(perms+i, buf, sizeof(buf));
                     fputs(buf, stdout);
                 }
                 putchar(')');