From c628db82acff738763d90ecfe1ca9fd1d1cdbc7f 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..79962c142 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 = "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, strlen(bound))) {
             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",