core.cc,linux.cc: add ${iface} (#603)

* core.cc,linux.cc: add ${iface}

* doc/variables.xml: add ${iface}

* Remove code smells

* linux.cc: Add for loop to iterate interfaces

* Index all NICs

* linux.cc: Allow+Remove NIC exclusion

* linux.cc: Remove code smells

* fix code smell

* switch skip by strcmpreturn

doc/variables.xml

@@ -1573,6 +1573,16 @@
         (i.e. contain at least one decimal place).
         <para /></listitem>
     </varlistentry>
+    <varlistentry>
+        <term>
+            <command>
+                <option>iface</option>
+            </command>
+            <option>(number)</option>
+        </term>
+        <listitem>Display interface names starting from 1, eg ${iface 1}.
+        <para /></listitem>
+    </varlistentry>
     <varlistentry>
         <term>
             <command>

src/core.cc

@@ -611,9 +611,6 @@ struct text_object *construct_text_object(char *s, const char *arg, long line,
   /* information from sony_laptop kernel module
    * /sys/devices/platform/sony-laptop */
   END OBJ(sony_fanspeed, 0) obj->callbacks.print = &get_sony_fanspeed;
-  END OBJ_IF(if_gw, &update_gateway_info) obj->callbacks.iftest =
-      &gateway_exists;
-  obj->callbacks.free = &free_gateway_info;
   END OBJ_ARG(ioscheduler, 0, "get_ioscheduler needs an argument (e.g. hda)")
       obj->data.s = strndup(dev_name(arg), text_buffer_size.get(*state));
   obj->callbacks.print = &print_ioscheduler;
@@ -1449,9 +1446,15 @@ struct text_object *construct_text_object(char *s, const char *arg, long line,
   END OBJ(gw_iface, &update_gateway_info) obj->callbacks.print =
       &print_gateway_iface;
   obj->callbacks.free = &free_gateway_info;
+  END OBJ_IF(if_gw, &update_gateway_info) obj->callbacks.iftest =
+      &gateway_exists;
+  obj->callbacks.free = &free_gateway_info;
   END OBJ(gw_ip, &update_gateway_info) obj->callbacks.print = &print_gateway_ip;
   obj->callbacks.free = &free_gateway_info;
-#endif /* !__linux__ */
+  END OBJ(iface, &update_gateway_info2) obj->data.s = STRNDUP_ARG;
+  obj->callbacks.print = &print_gateway_iface2;
+  obj->callbacks.free = &gen_free_opaque;
+#endif /* __linux__ */
 #if (defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || \
      defined(__DragonFly__) || defined(__OpenBSD__)) &&     \
     (defined(i386) || defined(__i386__))

src/linux.cc

@@ -94,8 +94,14 @@ struct sysfs {
   float factor, offset;
 };
 
+/* To be used inside upspeed/f downspeed/f as ${gw_iface} variable */
 char e_iface[50];
 
+/* To use ${iface X} where X is a number and will
+ * return the current X NIC name */
+static const unsigned int iface_len = 64U;
+static char interfaces_arr[iface_len][iface_len] = {""};
+
 #define SHORTSTAT_TEMPL "%*s %llu %llu %llu"
 #define LONGSTAT_TEMPL "%*s %llu %llu %llu "
 
@@ -287,10 +293,65 @@ void update_gateway_info_failure(const char *reason) {
 /* Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT */
 #define RT_ENTRY_FORMAT "%63s %lx %lx %x %*d %*d %*d %lx %*d %*d %*d\n"
 
+FILE *check_procroute() {
+  FILE *fp;
+  if ((fp = fopen("/proc/net/route", "r")) == nullptr) {
+    update_gateway_info_failure("fopen()");
+    return nullptr;
+  }
+
+  /* skip over the table header line, which is always present */
+  if (fscanf(fp, "%*[^\n]\n") < 0) {
+    fclose(fp);
+    return nullptr;
+  }
+
+  return fp;
+}
+
+int update_gateway_info2(void) {
+  FILE *fp;
+  char iface[iface_len];
+  unsigned long dest;
+  unsigned long gate;
+  unsigned long mask;
+  unsigned int flags;
+  unsigned int x = 1;
+  unsigned int z = 1;
+  int strcmpreturn;
+
+  if((fp = check_procroute()) != nullptr) {
+    while (!feof(fp)) {
+      strcmpreturn = 1;
+      if (fscanf(fp, RT_ENTRY_FORMAT, iface, &dest, &gate, &flags, &mask) != 5) {
+        update_gateway_info_failure("fscanf()");
+        break;
+      }
+      if (!(dest || mask) && ((flags & RTF_GATEWAY) || !gate)) {
+        snprintf(e_iface, 49, "%s", iface);
+      }
+      if (1U == x) {
+        snprintf(interfaces_arr[x++], iface_len - 1, "%s", iface);
+        continue;
+      } else if (0 == strcmp(iface, interfaces_arr[x - 1])) {
+        continue;
+      }
+      for (z = 1; z < iface_len - 1 && strcmpreturn == 1; z++) {
+        strcmpreturn = strcmp(iface, interfaces_arr[z]);
+      }
+      if (strcmpreturn == 1) {
+        snprintf(interfaces_arr[x++], iface_len - 1, "%s", iface);
+      }
+    }
+    fclose(fp);
+  }
+  return 0;
+}
+
 int update_gateway_info(void) {
   FILE *fp;
   struct in_addr ina;
-  char iface[64];
+  char iface[iface_len];
   unsigned long dest, gate, mask;
   unsigned int flags;
 
@@ -298,31 +359,22 @@ int update_gateway_info(void) {
   free_and_zero(gw_info.ip);
   gw_info.count = 0;
 
-  if ((fp = fopen("/proc/net/route", "r")) == nullptr) {
-    update_gateway_info_failure("fopen()");
-    return 0;
-  }
-
-  /* skip over the table header line, which is always present */
-  if (fscanf(fp, "%*[^\n]\n") < 0) {
+  if((fp = check_procroute()) != nullptr) {
+    while (!feof(fp)) {
+      if (fscanf(fp, RT_ENTRY_FORMAT, iface, &dest, &gate, &flags, &mask) != 5) {
+        update_gateway_info_failure("fscanf()");
+        break;
+      }
+      if (!(dest || mask) && ((flags & RTF_GATEWAY) || !gate)) {
+        gw_info.count++;
+        snprintf(e_iface, 49, "%s", iface);
+        SAVE_SET_STRING(gw_info.iface, iface)
+        ina.s_addr = gate;
+        SAVE_SET_STRING(gw_info.ip, inet_ntoa(ina))
+      }
+    }
     fclose(fp);
-    return 0;
   }
-
-  while (!feof(fp)) {
-    if (fscanf(fp, RT_ENTRY_FORMAT, iface, &dest, &gate, &flags, &mask) != 5) {
-      update_gateway_info_failure("fscanf()");
-      break;
-    }
-    if (!(dest || mask) && ((flags & RTF_GATEWAY) || !gate)) {
-      gw_info.count++;
-      snprintf(e_iface, 49, "%s", iface);
-      SAVE_SET_STRING(gw_info.iface, iface)
-      ina.s_addr = gate;
-      SAVE_SET_STRING(gw_info.ip, inet_ntoa(ina))
-    }
-  }
-  fclose(fp);
   return 0;
 }
 
@@ -341,10 +393,38 @@ int gateway_exists(struct text_object *obj) {
 
 void print_gateway_iface(struct text_object *obj, char *p, unsigned int p_max_size) {
   (void)obj;
-
   snprintf(p, p_max_size, "%s", gw_info.iface);
 }
 
+void print_gateway_iface2(struct text_object *obj, char *p, unsigned int p_max_size) {
+  long int z = 0;
+  unsigned int x = 1;
+  unsigned int found = 0;
+  char buf[iface_len * iface_len] = {""};
+  char *buf_ptr = buf;
+
+  if (0 == strcmp(obj->data.s, "")) {
+    for (; x < iface_len - 1; x++) {
+      if (0 == strcmp("", interfaces_arr[x])) {
+        break;
+      }
+      buf_ptr += snprintf(buf_ptr, iface_len - 1, "%s, ", interfaces_arr[x]);
+      found = 1;
+    }
+    if (1 == found) {
+      --buf_ptr;
+      *(--buf_ptr) = '\0';
+    }
+    snprintf(p, p_max_size, "%s", buf);
+    return;
+  }
+
+  z = strtol(obj->data.s, (char **)NULL, 10);
+  if ((iface_len - 1) > z) {
+    snprintf(p, p_max_size, "%s", interfaces_arr[z]);
+  }
+}
+
 void print_gateway_ip(struct text_object *obj, char *p, unsigned int p_max_size) {
   (void)obj;
 

src/linux.h

@@ -33,9 +33,11 @@ void print_ioscheduler(struct text_object *, char *, unsigned int);
 void print_laptop_mode(struct text_object *, char *, unsigned int);
 
 int update_gateway_info(void);
+int update_gateway_info2(void);
 void free_gateway_info(struct text_object *obj);
 int gateway_exists(struct text_object *);
 void print_gateway_iface(struct text_object *, char *, unsigned int);
+void print_gateway_iface2(struct text_object *, char *, unsigned int);
 void print_gateway_ip(struct text_object *, char *, unsigned int);
 
 enum { PB_BATT_STATUS, PB_BATT_PERCENT, PB_BATT_TIME };