simplified conf file parsing (#582)

doc/Advanced.md

@@ -1,6 +1,10 @@
 # Advanced Configuration
 
 
+## Configuration Files
+
+Read about [Configuration Files](ConfigurationFiles.md) as they might come in handy – especially, but not limited to, if edges or supernodes shall be run as a service (see below) or in case of bulk automated parameter generation for mass deployment.
+
 ## Running edge as a Service
 
 edge can also be run as a service instead of cli:

doc/ConfigurationFiles.md

@@ -0,0 +1,73 @@
+# Configuration Files
+
+To help deployment of locally different configurations, n2n supports the use of configuration files for `edge` and `supernode`.
+
+They are plain text files and contain the desired command line options, **one per line**.
+
+The exemplary command line
+
+```bash
+sudo edge -c mynetwork -k mysecretpass -a 192.168.100.1 -f -l supernode.ntop.org:7777
+```
+
+translates into the following `edge.conf` file:
+
+```
+-c mynetwork
+-k mysecretpass
+-a 192.168.100.1
+-f
+-l supernode.ntop.org:7777
+```
+
+which can be loaded by
+
+```
+sudo ./edge edge.conf
+```
+
+The `.conf` file syntax also allows `=` between parameter and its option:
+
+```
+-c=mynetwork
+-k=mysecretpass
+-a=192.168.100.1
+-f
+-l=supernode.ntop.org:7777
+```
+
+When used with `=`, there is no whitespace allowed between parameter, delimter (`=`), and option. So, do **not** put `-c = mynetwork` – it is required to be `-c=mynetwork`.
+
+Comment lines starting with a hash '#' are ignored.
+
+```
+# automated edge configuration
+# created by bot7
+# on April 31, 2038 – 1800Z
+-c    mynetwork
+-k    mysecretpass
+-a    192.168.100.1
+-f
+# --- supernode section ---
+-l    supernode.ntop.org:7777
+```
+
+Long options can be used as well. Please note the double minus/dash character `--`, just like on command line:
+
+```
+# automated edge configuration
+# created by bot7
+# on April 31, 2038 – 1800Z
+--community    mynetwork
+-k             mysecretpass
+-a             192.168.100.1
+-f
+# --- supernode section ---
+-l             supernode.ntop.org:7777
+```
+
+If using a configuration file, its filename needs to be supplied as first parameter to `edge` or `supernode`. If required, additional command line parameters can be supplied afterwards:
+
+```
+sudo edge edge.conf -A5
+```

src/edge.c

@@ -1,5 +1,5 @@
 /**
- * (C) 2007-20 - ntop.org and contributors
+ * (C) 2007-21 - ntop.org and contributors
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -525,14 +525,14 @@ static int setOption (int optkey, char *optargument, n2n_tuntap_priv_config_t *e
 
 static const struct option long_options[] =
     {
-        { "community",             required_argument, NULL, 'c' },
+        { "community",         required_argument, NULL, 'c' },
         { "supernode-list",    required_argument, NULL, 'l' },
-        { "tap-device",            required_argument, NULL, 'd' },
+        { "tap-device",        required_argument, NULL, 'd' },
-        { "euid",                        required_argument, NULL, 'u' },
+        { "euid",              required_argument, NULL, 'u' },
-        { "egid",                        required_argument, NULL, 'g' },
+        { "egid",              required_argument, NULL, 'g' },
-        { "help"     ,                 no_argument,             NULL, 'h' },
+        { "help"     ,         no_argument,       NULL, 'h' },
-        { "verbose",                 no_argument,             NULL, 'v' },
+        { "verbose",           no_argument,       NULL, 'v' },
-        { NULL,                            0,                                 NULL,    0    }
+        { NULL,                0,                 NULL,  0  }
     };
 
 /* *************************************************** */
@@ -549,8 +549,10 @@ static int loadFromCLI (int argc, char *argv[], n2n_edge_conf_t *conf, n2n_tunta
 #endif
                             ,
                             long_options, NULL)) != '?') {
+
         if(c == 255) break;
         setOption(c, optarg, ec, conf);
+
     }
 
     return 0;
@@ -579,10 +581,11 @@ static char *trim (char *s) {
 /* parse the configuration file */
 static int loadFromFile (const char *path, n2n_edge_conf_t *conf, n2n_tuntap_priv_config_t *ec) {
 
-    char buffer[4096], *line, *key, *value;
+    char buffer[4096], *line;
-    u_int line_len, opt_name_len;
+    char *line_vec[3];
+    int tmp;
+
     FILE *fd;
-    const struct option *opt;
 
     fd = fopen(path, "r");
 
@@ -591,71 +594,29 @@ static int loadFromFile (const char *path, n2n_edge_conf_t *conf, n2n_tuntap_pri
         return -1;
     }
 
+    // we mess around with optind, better save it
+    tmp = optind;
+
     while((line = fgets(buffer, sizeof(buffer), fd)) != NULL) {
         line = trim(line);
-        value = NULL;
 
-        if((line_len = strlen(line)) < 2 || line[0] == '#')
+        if(strlen(line) < 2 || line[0] == '#')
             continue;
 
-        if(!strncmp(line, "--", 2)) { /* long opt */
+        // executable, cannot be omitted, content can be anything
-            key = &line[2], line_len -= 2;
+        line_vec[0] = line;
-
+        // first token, e.g. `-p` or `-A3', eventually followed by a whitespace or '=' delimiter
-            opt = long_options;
+        line_vec[1] = strtok(line, "\t =");
-            while(opt->name != NULL) {
+        // separate parameter option, if present
-                opt_name_len = strlen(opt->name);
+        line_vec[2] = strtok(NULL, "\t ");
-
+        // not to duplicate the option parser code, call loadFromCLI and pretend we have no option read yet
-                if(!strncmp(key, opt->name, opt_name_len)
+        optind = 1;
-                   && (line_len <= opt_name_len
+        // if second token present (optional argument, not part of first), then announce 3 vector members
-                       || key[opt_name_len] == '\0'
+        loadFromCLI(line_vec[2] ? 3 : 2, line_vec, conf, ec);
-                       || key[opt_name_len] == ' '
-                       || key[opt_name_len] == '=')) {
-                    if(line_len > opt_name_len) key[opt_name_len] = '\0';
-                    if(line_len > opt_name_len + 1) value = trim(&key[opt_name_len + 1]);
-
-                    // traceEvent(TRACE_NORMAL, "long key: %s value: %s", key, value);
-                    setOption(opt->val, value, ec, conf);
-                    break;
-                }
-
-                opt++;
-            }
-        } else if(line[0] == '-') { /* short opt */
-            char *equal;
-
-            key = &line[1], line_len--;
-
-            equal = strchr(line, '=');
-
-            if(equal) {
-                equal[0] = '\0';
-                value = &equal[1];
-
-                if((value[0] == '\0') && (key[1] != '\0'))
-                    value = &key[1];
-            } else {
-                value = NULL;
-
-                /* Adding an exception for -A_ -z_ which can come
-                   without '=' and even without any further data */
-
-                if(key[0] == 'z') {
-                    if(key[1]) value = &key[1];
-                    key = "z";
-                } else if(key[0] == 'A') {
-                    if(key[1]) value = &key[1];
-                    key = "A";
-                }
-            }
-            // traceEvent(TRACE_NORMAL, "key: %c value: %s", key[0], value);
-            setOption(key[0], value, ec, conf);
-        } else {
-            traceEvent(TRACE_WARNING, "Skipping unrecognized line: %s", line);
-            continue;
-        }
     }
 
     fclose(fd);
+    optind = tmp;
 
     return 0;
 }
@@ -783,8 +744,9 @@ int main (int argc, char* argv[]) {
     } else if(argc > 1)
         rc = loadFromCLI(argc, argv, &conf, &ec);
     else
+
 #ifdef WIN32
-        /* Load from current directory */
+        // load from current directory
         rc = loadFromFile("edge.conf", &conf, &ec);
 #else
         rc = -1;

src/sn.c

@@ -1,5 +1,5 @@
 /**
- * (C) 2007-20 - ntop.org and contributors
+ * (C) 2007-21 - ntop.org and contributors
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -455,10 +455,11 @@ static char *trim (char *s) {
 /* parse the configuration file */
 static int loadFromFile (const char *path, n2n_sn_t *sss) {
 
-    char buffer[4096], *line, *key, *value;
+    char buffer[4096], *line;
-    u_int line_len, opt_name_len;
+    char *line_vec[3];
+    int tmp;
+
     FILE *fd;
-    const struct option *opt;
 
     fd = fopen(path, "r");
 
@@ -467,55 +468,31 @@ static int loadFromFile (const char *path, n2n_sn_t *sss) {
         return -1;
     }
 
-    while((line = fgets(buffer, sizeof(buffer), fd)) != NULL) {
+    // we mess around with optind, better save it
+    tmp = optind;
 
+    while((line = fgets(buffer, sizeof(buffer), fd)) != NULL) {
         line = trim(line);
-        value = NULL;
 
-        if((line_len = strlen(line)) < 2 || line[0] == '#') {
+        if(strlen(line) < 2 || line[0] == '#') {
             continue;
         }
 
-        if(!strncmp(line, "--", 2)) { /* long opt */
+        // executable, cannot be omitted, content can be anything
-            key = &line[2], line_len -= 2;
+        line_vec[0] = line;
-
+        // first token, e.g. `-p`, eventually followed by a whitespace or '=' delimiter
-            opt = long_options;
+        line_vec[1] = strtok(line, "\t =");
-            while(opt->name != NULL) {
+        // separate parameter option, if present
-	        opt_name_len = strlen(opt->name);
+        line_vec[2] = strtok(NULL, "\t ");
-
+
-	        if(!strncmp(key, opt->name, opt_name_len)
+        // not to duplicate the option parser code, call loadFromCLI and pretend we have no option read yet
-	           && (line_len <= opt_name_len
+        optind = 1;
-	           || key[opt_name_len] == '\0'
+        // if separate second token present (optional argument, not part of first), then announce 3 vector members
-	           || key[opt_name_len] == ' '
+        loadFromCLI(line_vec[2] ? 3 : 2, line_vec, sss);
-	           || key[opt_name_len] == '=')) {
-	            if(line_len > opt_name_len) {
-                  key[opt_name_len] = '\0';
-              }
-	            if(line_len > opt_name_len + 1) {
-                  value = trim(&key[opt_name_len + 1]);
-              }
-
-	            // traceEvent(TRACE_NORMAL, "long key: %s value: %s", key, value);
-	            setOption(opt->val, value, sss);
-	            break;
-	        }
-
-	        opt++;
-            }
-        } else if(line[0] == '-') { /* short opt */
-            key = &line[1], line_len--;
-            if(line_len > 1) key[1] = '\0';
-            if(line_len > 2) value = trim(&key[2]);
-
-            // traceEvent(TRACE_NORMAL, "key: %c value: %s", key[0], value);
-            setOption(key[0], value, sss);
-        } else {
-            traceEvent(TRACE_WARNING, "Skipping unrecognized line: %s", line);
-            continue;
-        }
     }
 
     fclose(fd);
+    optind = tmp;
 
     return 0;
 }
@@ -626,7 +603,7 @@ int main (int argc, char * const argv[]) {
     } else
 
 #ifdef WIN32
-        /* Load from current directory */
+        // load from current directory
         rc = loadFromFile("supernode.conf", &sss_node);
 #else
         rc = -1;
@@ -636,7 +613,6 @@ int main (int argc, char * const argv[]) {
         help();
     }
 
-
 #if defined(N2N_HAVE_DAEMON)
     if(sss_node.daemon) {
         setUseSyslog(1); /* traceEvent output now goes to syslog. */