tools, irm: move binary check to library

This will make the library check if the user has permissions to
execute the binary when auto is set. This prevents writing malicious
software that would use the irmd to execute other applications to
which the user has no access.

2 files changed, 17 insertions, 7 deletions

diff --git a/src/lib/irm.c b/src/lib/irm.c
index 6b296258..93963eb1 100644
--- a/src/lib/irm.c
+++ b/src/lib/irm.c
@@ -29,6 +29,7 @@
 #include <ouroboros/sockets.h>
 
 #include <stdlib.h>
+#include <sys/stat.h>
 
 pid_t irm_create_ipcp(char *         name,
                       enum ipcp_type ipcp_type)
@@ -246,10 +247,17 @@ int irm_bind(char *   name,
         irm_msg_t msg = IRM_MSG__INIT;
         irm_msg_t * recv_msg = NULL;
         int ret = -1;
+        struct stat s;
 
         if (name == NULL || ap_name == NULL)
                 return -EINVAL;
 
+        if (stat(ap_name, &s) != 0)
+                return -ENOENT;
+
+        if (!(s.st_mode & S_IXUSR))
+                return -EPERM;
+
         msg.code = IRM_MSG_CODE__IRM_BIND;
         msg.dst_name = name;
         msg.ap_name = ap_name;
diff --git a/src/tools/irm/irm_bind.c b/src/tools/irm/irm_bind.c
index 92ebdd8a..45da6e4c 100644
--- a/src/tools/irm/irm_bind.c
+++ b/src/tools/irm/irm_bind.c
@@ -22,7 +22,7 @@
 
 #include <stdio.h>
 #include <string.h>
-#include <sys/stat.h>
+#include <errno.h>
 
 #include <ouroboros/irm.h>
 
@@ -45,7 +45,7 @@ int do_bind(int argc, char ** argv)
         char * name = NULL;
         char * ap_name = NULL;
         uint16_t flags = 0;
-        struct stat s;
+        int ret = 0;
 
         while (argc > 0) {
                 if (matches(*argv, "name") == 0) {
@@ -79,15 +79,17 @@ int do_bind(int argc, char ** argv)
                 return -1;
         }
 
-        if (stat(ap_name, &s) != 0) {
-                printf("Application %s does not exist.\n", ap_name);
+        ret = irm_bind(name, ap_name, flags, argc, argv);
+        if (ret == -ENOENT) {
+                printf("%s does not exist.\n", ap_name);
                 return -1;
         }
 
-        if (!(s.st_mode & S_IXUSR)) {
-                printf("Application %s is not executable.\n", ap_name);
+        if (ret == -EPERM) {
+                printf("Cannot execute %s, please check permissions.\n",
+                        ap_name);
                 return -1;
         }
 
-        return irm_bind(name, ap_name, flags, argc, argv);
+        return ret;
 }