Fixes warnings for possible string truncation with strncpy()

All of these fixes handles strncpy(), and the compiler warning have been
silenced by checking the length before copying the string, we check with
'>=' which means that the string must be one smaller and therefore have
room for at least one NULL terminating character, if this fails the
function provides a error message and/or return.

Some of the buffer lengths had a '+ 1' appended, some of these have been
removed. I'm also using sizeof() operator, in case we later want to
change the buffer size.

Most of the  previous solutions also checked for NULL terminated strings
but the compiler wasn't satisfied with it happening *after* the command
to strncpy().

Author: havardAasen

src/emc/rs274ngc/interp_o_word.cc

@@ -541,7 +541,7 @@ int Interp::control_back_to( block_pointer block, // pointer to block
 			     setup_pointer settings)   // pointer to machine settings
 {
     static char name[] = "control_back_to";
-    char newFileName[PATH_MAX+1];
+    char newFileName[PATH_MAX];
     FILE *newFP;
     offset_map_iterator it;
     offset_pointer op;
@@ -561,12 +561,12 @@ int Interp::control_back_to( block_pointer block, // pointer to block
 	    newFP = fopen(op->filename, "r");
 	    // set the line number
 	    settings->sequence_number = 0;
-            strncpy(settings->filename, op->filename, sizeof(settings->filename));
-            if (settings->filename[sizeof(settings->filename)-1] != '\0') {
+            if (strlen(op->filename) >= sizeof(settings->filename)) {
                 fclose(settings->file_pointer);
                 logOword("filename too long: %s", op->filename);
                 ERS(NCE_UNABLE_TO_OPEN_FILE, op->filename);
             }
+            strncpy(settings->filename, op->filename, sizeof(settings->filename));
 
 	    if (newFP) {
 		// close the old file...
@@ -597,11 +597,11 @@ int Interp::control_back_to( block_pointer block, // pointer to block
 	if (settings->file_pointer)
 	    fclose(settings->file_pointer);
 	settings->file_pointer = newFP;
-        strncpy(settings->filename, newFileName, sizeof(settings->filename));
-        if (settings->filename[sizeof(settings->filename)-1] != '\0') {
+        if (strlen(newFileName) >= sizeof(settings->filename)) {
             logOword("new filename '%s' is too long (max len %zu)\n", newFileName, sizeof(settings->filename)-1);
-            settings->filename[sizeof(settings->filename)-1] = '\0'; // oh well, truncate the filename
+            ERS(NCE_UNABLE_TO_OPEN_FILE, newFileName);
         }
+        strncpy(settings->filename, newFileName, sizeof(settings->filename));
     } else {
 	char *dirname = getcwd(NULL, 0);
 	logOword("fopen: |%s| failed CWD:|%s|", newFileName,

src/emc/rs274ngc/interp_read.cc

@@ -1595,8 +1595,10 @@ int Interp::read_o(    /* ARGUMENTS                                     */
 
 	  // Subroutine name not provided in Fanuc syntax, so pull from
 	  // context
+          if (strlen(_setup.sub_context[_setup.call_level].subName) >= sizeof(oNameBuf))
+              ERS(NCE_UNABLE_TO_OPEN_FILE, _setup.sub_context[_setup.call_level].subName);
 	  strncpy(oNameBuf, _setup.sub_context[_setup.call_level].subName,
-		  LINELEN+1);
+                  sizeof(oNameBuf));
       } else
 	  // any other m-code should have been handled by read_m()
 	  OERR(_("%d: Bug:  Non-m98/m99 M-code passed to read_o(): '%s'"),

src/emc/rs274ngc/rs274ngc_pre.cc

@@ -2492,12 +2492,12 @@ int Interp::ini_load(const char *filename)
 
     char parameter_file_name[LINELEN]={};
     if (NULL != (inistring = inifile.Find("PARAMETER_FILE", "RS274NGC"))) {
-        strncpy(parameter_file_name, inistring, LINELEN);
-
-        if (parameter_file_name[LINELEN-1] != '\0') {
-            logDebug("%s:[RS274NGC]PARAMETER_FILE is too long (max len %d)", filename, LINELEN-1);
+        if (strlen(inistring) >= sizeof(parameter_file_name)) {
+            logDebug("%s:[RS274NGC]PARAMETER_FILE is too long (max len %zu)",
+                     filename, sizeof(parameter_file_name)-1);
         } else {
-          logDebug("found PARAMETER_FILE:%s:", parameter_file_name);
+            strncpy(parameter_file_name, inistring, sizeof(parameter_file_name));
+            logDebug("found PARAMETER_FILE:%s:", parameter_file_name);
         }
     } else {
       // not found, leave RS274NGC_PARAMETER_FILE alone

src/emc/task/emctask.cc

@@ -112,7 +112,7 @@ static void user_defined_add_m_code(int num, double arg1, double arg2)
 
 int emcTaskInit()
 {
-    char mdir[MAX_M_DIRS][PATH_MAX+1];
+    char mdir[MAX_M_DIRS][PATH_MAX];
     int num,dct,dmax;
     char path[EMC_SYSTEM_CMD_LEN];
     struct stat buf;
@@ -123,18 +123,14 @@ int emcTaskInit()
 
     // Identify user_defined_function directories
     if (NULL != (inistring = inifile.Find("PROGRAM_PREFIX", "DISPLAY"))) {
-        strncpy(mdir[0],inistring, sizeof(mdir[0]));
-        if (mdir[0][sizeof(mdir[0])-1] != '\0') {
+        if (strlen(inistring) >= sizeof(mdir[0])) {
             rcs_print("[DISPLAY]PROGRAM_PREFIX too long (max len %zu)\n", sizeof(mdir[0]));
             return -1;
         }
+        strncpy(mdir[0], inistring, sizeof(mdir[0]));
     } else {
         // default dir if no PROGRAM_PREFIX
-        strncpy(mdir[0],"nc_files", sizeof(mdir[0]));
-        if (mdir[0][sizeof(mdir[0])-1] != '\0') {
-            rcs_print("default nc_files too long (max len %zu)\n", sizeof(mdir[0]));
-            return -1;
-        }
+        strncpy(mdir[0], "nc_files", sizeof(mdir[0]));
     }
     dmax = 1; //one directory mdir[0],  USER_M_PATH specifies additional dirs
 
@@ -146,21 +142,22 @@ int emcTaskInit()
 
         for (dct=1; dct < MAX_M_DIRS; dct++) mdir[dct][0] = 0;
 
-        strncpy(tmpdirs,inistring, sizeof(tmpdirs));
-        if (tmpdirs[sizeof(tmpdirs)-1] != '\0') {
+        if (strlen(inistring) >= sizeof(tmpdirs)) {
             rcs_print("[RS274NGC]USER_M_PATH too long (max len %zu)\n", sizeof(tmpdirs));
             return -1;
         }
+        strncpy(tmpdirs, inistring, sizeof(tmpdirs));
 
         nextdir = strtok(tmpdirs,":");  // first token
         dct = 1;
         while (dct < MAX_M_DIRS) {
             if (nextdir == NULL) break; // no more tokens
-            strncpy(mdir[dct],nextdir, sizeof(mdir[dct]));
-            if (mdir[dct][sizeof(mdir[dct])-1] != '\0') {
-                rcs_print("[RS274NGC]USER_M_PATH component (%s) too long (max len %zu)\n", nextdir, sizeof(mdir[dct]));
+            if (strlen(nextdir) >= sizeof(mdir[dct])) {
+                rcs_print("[RS274NGC]USER_M_PATH component (%s) too long (max len %zu)\n",
+                          nextdir, sizeof(mdir[dct]));
                 return -1;
             }
+            strncpy(mdir[dct], nextdir, sizeof(mdir[dct]));
             nextdir = strtok(NULL,":");
             dct++;
         }

src/emc/usr_intf/emcrsh.cc

@@ -609,18 +609,12 @@ static int commandHello(connectionRecType *context)
   if (strcmp(pch, pwd) != 0) return -1;
 
   pch = strtok(NULL, delims);
-  if (pch == NULL) return -1;
+  if (pch == NULL || strlen(pch) >= sizeof(context->hostName)) return -1;
   strncpy(context->hostName, pch, sizeof(context->hostName));
-  if (context->hostName[sizeof(context->hostName)-1] != '\0') {
-    return -1;
-  }
 
   pch = strtok(NULL, delims);
-  if (pch == NULL) return -1;
+  if (pch == NULL|| strlen(pch) >= sizeof(context->version)) return -1;
   strncpy(context->version, pch, sizeof(context->version));
-  if (context->version[sizeof(context->version)-1] != '\0') {
-    return -1;
-  }
 
   context->linked = true;
   printf("Connected to %s\n", context->hostName);
@@ -1169,12 +1163,12 @@ static cmdResponseType setOpen(char *s, connectionRecType *context)
 
   pch = strtok(NULL, "\n\r\0");
   if (pch == NULL) return rtStandardError;
-
-  strncpy(context->progName, pch, sizeof(context->progName));
-  if (context->progName[sizeof(context->progName) - 1] != '\0') {
-    fprintf(stderr, "linuxcncrsh: 'set open' filename too long for context (got %lu bytes, max %lu)", (unsigned long)strlen(pch), (unsigned long)sizeof(context->progName));
+  if (strlen(pch) >= sizeof(context->progName)) {
+    fprintf(stderr, "linuxcncrsh: 'set open' filename too long for context (got %lu bytes, max %lu)",
+            (unsigned long)strlen(pch), (unsigned long)sizeof(context->progName));
     return rtStandardError;
   }
+  strncpy(context->progName, pch, sizeof(context->progName));
 
   if (sendProgramOpen(context->progName) != 0) return rtStandardError;
   return rtNoError;

src/hal/user_comps/mb2hal/mb2hal_init.c

@@ -696,7 +696,11 @@ retCode init_mb_links()
             this_mb_link->lp_link_type = this_mb_tx->cfg_link_type;
 
             if (this_mb_link->lp_link_type == linkRTU) { //serial
-                strncpy(this_mb_link->lp_serial_device, this_mb_tx->cfg_serial_device, MB2HAL_MAX_DEVICE_LENGTH-1);
+                if (strlen(this_mb_tx->cfg_serial_device) >= MB2HAL_MAX_DEVICE_LENGTH) {
+                    ERR(gbl.init_dbg, "serial_device name to long [%s]", this_mb_tx->cfg_serial_device);
+                    return retERR;
+                }
+                strncpy(this_mb_link->lp_serial_device, this_mb_tx->cfg_serial_device, MB2HAL_MAX_DEVICE_LENGTH);
                 this_mb_link->lp_serial_baud=this_mb_tx->cfg_serial_baud;
 
                 if (strcasecmp(this_mb_tx->cfg_serial_parity, "even") == 0) {
@@ -723,7 +727,11 @@ retCode init_mb_links()
                 }
             }
             else { //tcp
-                strncpy(this_mb_link->lp_tcp_ip, this_mb_tx->cfg_tcp_ip, sizeof(this_mb_tx->cfg_tcp_ip)-1);
+                if (strlen(this_mb_tx->cfg_tcp_ip) >= sizeof(this_mb_link->lp_tcp_ip)) {
+                    ERR(gbl.init_dbg, "tcp_ip too long [%s]", this_mb_tx->cfg_tcp_ip);
+                    return retERR;
+                }
+                strncpy(this_mb_link->lp_tcp_ip, this_mb_tx->cfg_tcp_ip, sizeof(this_mb_tx->cfg_tcp_ip));
                 this_mb_link->lp_tcp_port=this_mb_tx->cfg_tcp_port;
 
                 this_mb_link->modbus = modbus_new_tcp(this_mb_link->lp_tcp_ip, this_mb_link->lp_tcp_port);

src/libnml/cms/cms_cfg.cc

@@ -110,6 +110,11 @@ int load_nml_config_file(const char *file)
 
     CONFIG_FILE_INFO *info = new CONFIG_FILE_INFO();
     info->lines_list = new LinkedList();
+    if (strlen(file) >= 80) {
+        rcs_print_error("cms_config: file name too long\n");
+        loading_config_file = 0;
+        return -1;
+    }
     strncpy(info->file_name, file, 80);
     FILE *fp;
     fp = fopen(file, "r");