From a309912c8b80e89b0968bd7d24f10af8bb0afa20 Mon Sep 17 00:00:00 2001
From: Brendan Chandler <bchandler@anl.gov>
Date: Tue, 16 Feb 2021 12:51:11 -0600
Subject: [PATCH] RTEMS DHCP: Use safer versions of string functions

Use strtok_r rather than strtok

Use strlen() rather than harcoded string size.  GCC should optimize
this to the hardcoded string size, so the result should be the same
but maybe prevents future mistakes.

replace strncpy() with snprintf() to avoid issues with NULL terminated
strings.
---
 modules/libcom/RTEMS/posix/rtems_init.c | 67 ++++++++++++++++---------
 1 file changed, 44 insertions(+), 23 deletions(-)

diff --git a/modules/libcom/RTEMS/posix/rtems_init.c b/modules/libcom/RTEMS/posix/rtems_init.c
index 4b082b34d..470905559 100644
--- a/modules/libcom/RTEMS/posix/rtems_init.c
+++ b/modules/libcom/RTEMS/posix/rtems_init.c
@@ -707,50 +707,71 @@ dhcpcd_hook_handler(rtems_dhcpcd_hook *hook, char *const *env)
     char iName[16];
     char *name;
     char *value;
-
+    char * env_position;
+    
 	(void)hook;
 
     char ifnamebuf[IF_NAMESIZE];
     sprintf(ifnamebuf, "%s", getPrimaryNetworkInterface());
 
     while (*env != NULL) {
-        name = strtok(*env,"=");
-        value = strtok(NULL,"=");
+        char const * interface = "interface";
+        char const * reason = "reason";
+        char const * bound_str = "BOUND";
+        
+        name = strtok_r(*env,"=", &env_position);
+        value = strtok_r(NULL,"=", &env_position);
         printf("all out ---> %s = %s\n", name, value);
-        if (!strncmp(name, "interface", 9) && !strcmp(value,  ifnamebuf))
-			 strncpy(iName, value, 16);
-		if (!strncmp(name, "reason", 6) && !strncmp(value, "BOUND", 5)){
+
+        if (!strncmp(name, interface, strlen(interface)) &&
+            !strcmp(value,  ifnamebuf)) {
+            snprintf(iName, sizeof(iName), "%s", value);
+        }
+
+        if (!strncmp(name, reason, strlen(reason)) &&
+            !strncmp(value, bound_str, strlen(bound_str))) {
             printf ("Interface %s bounded\n", iName);
             bound = 1;
-		}
-		if (bound) {
+        }
+        
+        if (bound) {
             // as there is no ntp-support in rtems-libbsd, we call our own client
-            if(!strncmp(name, "new_ntp_servers", 15))
-                strcpy(rtemsInit_NTP_server_ip,value);
-            if(!strncmp(name, "new_host_name", 13))
+            char const * new_ntp_servers = "new_ntp_servers";
+            char const * new_host_name = "new_host_name";
+            char const * new_tftp_server_name = "new_tftp_server_name";
+            
+            if (!strncmp(name, new_ntp_servers, strlen(new_ntp_servers)))
+                snprintf(rtemsInit_NTP_server_ip,
+                         sizeof(rtemsInit_NTP_server_ip),
+                         "%s", value);
+            
+            if (!strncmp(name, new_host_name, strlen(new_host_name)))
                 sethostname (value, strlen (value));
-            if(!strncmp(name, "new_tftp_server_name", 20)){
-                //printf(" new_tftp_server_name : %s\n", value);
-                strncpy(rtems_bsdnet_bootp_server_name,value, sizeof(bootp_server_name_init));
+            
+            if (!strncmp(name, new_tftp_server_name, strlen(new_tftp_server_name))){
+                snprintf(rtems_bsdnet_bootp_server_name,
+                         sizeof(bootp_server_name_init),
+                         "%s", value);
                 printf(" rtems_bsdnet_bootp_server_name : %s\n", rtems_bsdnet_bootp_server_name);
             }
             if(!strncmp(name, "new_bootfile_name", 20)){
-                //printf(" new_bootfile_name : %s\n", value);
-                strncpy(rtems_bsdnet_bootp_boot_file_name,value, sizeof(bootp_boot_file_name_init));
+                snprintf(rtems_bsdnet_bootp_boot_file_name,
+                         sizeof(bootp_boot_file_name_init),
+                         "%s", value);
                 printf(" rtems_bsdnet_bootp_boot_file_name : %s\n", rtems_bsdnet_bootp_boot_file_name);
             }
             if(!strncmp(name, "new_rtems_cmdline", 20)){
-                //printf(" new_rtems_cmdline : %s\n", value);
-                strncpy(rtems_bsdnet_bootp_cmdline,value, sizeof(bootp_cmdline_init));
+                snprintf(rtems_bsdnet_bootp_cmdline,
+                         sizeof(bootp_cmdline_init),
+                         "%s", value);
                 printf(" rtems_bsdnet_bootp_cmdline : %s\n", rtems_bsdnet_bootp_cmdline);
             }
-            // printf("---> %s = %s\n", name, value);
-        }
-		++env;
-	}
+          }
+        ++env;
+    }
     if (bound)
         epicsEventSignal(dhcpDone);
-    }
+}
 
 static rtems_dhcpcd_hook dhcpcd_hook = {
 	.name = "ioc boot",