From 882c2f75a8d5bc66746d52a30f8f9456a0038da2 Mon Sep 17 00:00:00 2001
From: 0scar <qgt268@alumni.ku.dk>
Date: Tue, 31 Dec 2024 02:26:20 +0100
Subject: Make internet link interfaces global state

The idea is to specifically watch some interfaces, and put a fs inotify
on them. Eventually...
---
 status.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 78 insertions(+), 25 deletions(-)

diff --git a/status.c b/status.c
index 7a7f9fb..2d9922e 100644
--- a/status.c
+++ b/status.c
@@ -56,7 +56,7 @@ struct interface_status {
     char ip6[INET6_ADDRSTRLEN];
   } address;
   char ssid[IW_ESSID_MAX_SIZE + 1];
-  char* name;
+  char name[IFNAMSIZ];
 };
 
 /* Prototypes */
@@ -91,6 +91,8 @@ static struct element statusbar[] = {
   {               date, {2, 500000}, {0}, {0}},
 };
 
+struct interface_status interfaces[8]; // surely noone has more than 8 interfaces.
+
 /* Functions */
 void
 date(char* buf) {
@@ -190,39 +192,80 @@ get_all_bat_status(char* buf) {
 void
 get_essid(char* if_name, char* dst) {
   /* Get the SSID */
+  struct iwreq wreq;
   size_t l = strlen(if_name);
   int sock = socket(AF_INET, SOCK_DGRAM, 0);
-  struct iwreq wreq;
+
+  if (sock == -1) {
+    return;
+  }
+
   memset(&wreq, 0, sizeof(struct iwreq));
 
-  setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, if_name, l);
+  if (setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE, if_name, l) == -1) {
+    close(sock);
+    return;
+  }
 
   strncpy(wreq.ifr_name, if_name, l);
 
   wreq.u.essid.pointer = dst;
   wreq.u.essid.length  = IW_ESSID_MAX_SIZE;
-  if (ioctl(sock, SIOCGIWESSID, &wreq) == -1) {
+  //printf("#%s#\n", dst);
+
+  // Test if we have wireless on this interface
+  if (ioctl(sock, SIOCGIWNAME, &wreq) != -1) {
+    // protocol stored in  wreq.u.name
+    close(sock);
+    return;
+  }
+
+  if (ioctl(sock, SIOCGIWESSID, &wreq) < 0) {
     dst[0] = '\0';
   }
-}
 
-struct interface_status status[8]; // surely noone has more than 8 interfaces.
+    close(sock);
+
+}
 
 void
 get_net_link_status(char* buf) {
   struct ifaddrs* if_addr;
   size_t n = 0;
   size_t c = 0;
-  struct interface_status status[8]; // surely noone has more than 8 interfaces.
-  memset(status, 0, sizeof(struct interface_status[8]));
 
   getifaddrs(&if_addr);
 
+  while (c < 8 && strlen(interfaces[c].name) > 0) {
+    c++;
+  }
+
   for (struct ifaddrs* ifa = if_addr; ifa != NULL; ifa = ifa->ifa_next) {
+    int i = 0;
+    const char* name = ifa->ifa_name;
+
+    while (i < c && strcmp(name, interfaces[i].name)) i++;
+
+    //if (i != c) {
+    //printf("found %s in %d\n", name, i);
+    //}
 
     /* We're not interested in interfaces that are not "up" */
-    if (!(ifa->ifa_flags & IFF_UP))
+    if (!(ifa->ifa_flags & IFF_LOWER_UP)) {
+      /* Remove it from the list */
+      if (i < c) {
+        /* Don't memmove if last element */
+        if (c - i > 1) {
+          memmove(&interfaces[i], &interfaces[i + 1], sizeof(struct interface_status) * (c - i));
+        }
+
+        /* "wipe" last element */
+        memset(&interfaces[c - 1], 0, sizeof(struct interface_status));
+
+        c--;
+      }
       continue;
+    }
 
     /* Ignore loopback interface flag */
     if (ifa->ifa_flags & IFF_LOOPBACK)
@@ -238,19 +281,10 @@ get_net_link_status(char* buf) {
     //   continue;
 
     /* Find the interface in status, if it exists */
-    struct interface_status* s = &status[c];
-    const char* name           = ifa->ifa_name;
+    struct interface_status s; // = &status[c];
+    memset(&s, 0, sizeof(struct interface_status));
 
-    int i                      = 0;
-    for (int i = 0; i < c; i++) {
-      if (!strcmp(name, status[i].name)) {
-        s = &status[i];
-      }
-    }
-    if (i == c)
-      c++;
-
-    s->name = ifa->ifa_name;
+        s = interfaces[i];
 
     if (ifa->ifa_addr != NULL) {
       const int family = ifa->ifa_addr->sa_family;
@@ -260,10 +294,10 @@ get_net_link_status(char* buf) {
 
       if (family == AF_INET) {
         strsize = INET_ADDRSTRLEN;
-        dst     = s->address.ip4;
+        dst     = s.address.ip4;
       } else if (family == AF_INET6) {
         strsize = INET6_ADDRSTRLEN;
-        dst     = s->address.ip6;
+        dst     = s.address.ip6;
       } else if (family == AF_PACKET) {
         continue;
       } else
@@ -276,13 +310,28 @@ get_net_link_status(char* buf) {
     }
 
     // Get the ESSID
-    get_essid(s->name, s->ssid);
+    get_essid(s.name, s.ssid);
+
+    /* if we got nothing out of it, don't increment */
+    if (ifa->ifa_addr == NULL && strlen(s.ssid) == 0)
+      continue;
+
+    /* If the interface didn't exist in interfaces before, we should add
+     * the name:) */
+    if (i == c) {
+      strncpy(s.name, name, IFNAMSIZ);
+      c++;
+    }
+
+    memcpy(&interfaces[i], &s, sizeof(struct interface_status));
+
   }
   freeifaddrs(if_addr);
 
+  memset(buf, 0, ELEMENT_STRBUF_SZ);
   for (int i = 0; i < c; i++) {
     // int i = 0; {
-    struct interface_status* s = &status[i];
+    struct interface_status* s = &interfaces[i];
     // Write the status string to the output buffer
     const size_t namelen = strlen(s->name);
     strncat(buf + n, s->name, namelen);
@@ -327,6 +376,8 @@ main(void) {
   struct timeval now;
   const struct timeval one_minute = {60, 0};
 
+  memset(interfaces, 0, sizeof(struct interface_status[8]));
+
   while (true) {
     gettimeofday(&now, NULL);
     unsigned i;
@@ -371,6 +422,8 @@ main(void) {
     memset(buf, 0, STATUS_STRBUF_SZ);
 
     for (i = 0; i < num_elems; i++) {
+      if (!strlen(statusbar[i].buf))
+        continue;
       strcat(buf, statusbar[i].buf);
       if (i != num_elems - 1)
         strcat(buf, ELEMENT_SEPERATOR);
-- 
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