Scan subnets in parallel, update readme, update gitignore

.gitignore

@@ -2,5 +2,6 @@
 !.gitignore
 !.screenshot.png
 minipam
+MinIPAM
 *.yaml
 *.json

README.md

@@ -11,6 +11,9 @@ there is no authorization mechanism built in.
 Scanning is kind of slow, but I prefer to keep it that way, since I don't need it to be fast, and I don't want to waste
 my compute resources. It doesn't matter for me if my scan completes within 1 minute or within 30 minutes.
 
+Subnets are scanned in parallel, but addresses in each subnet are still scanned sequentially. So complete scan takes as
+much time, as scanning of biggest subnet that you have.
+
 ![Screenshot](.screenshot.png)
 
 # Compilation
@@ -33,9 +36,13 @@ scan_subnets:
   - 192.168.145.0/24
   - 10.250.100.64.0/27
 delay_between_scans: 15m
+#Setting this to absolute path seems like a good idea :)
 persistence_location: "data.json"
+#Don't scan network and broadcast address, usually you want to leave this set to true
 exclude_special_addresses: true
 use_tls: false
+#IF use_tls is set to false, following two options are ignored.
+#key and cert and fullchain can be in one file. In this case, specify the same file in both fields
 tls_key_file: "key.pem"
 tls_cert_file: "fullchain.pem"
 ```

minipam.go

@@ -12,6 +12,7 @@ import (
 	"net/netip"
 	"os"
 	"os/exec"
+	"sync"
 	"time"
 )
 
@@ -120,9 +121,13 @@ func ping(addr string) bool {
 
 func scanner() {
 	for {
+		var wg sync.WaitGroup
+		var mutex sync.Mutex
+		for _, subnet := range conf.ScanSubnets {
 
-		for _, v := range conf.ScanSubnets {
-
+			go func(v string) {
+				wg.Add(1)
+				defer wg.Done()
 				persistenceSubnet, ok := p.Subnets[v]
 				if !ok {
 					persistenceSubnet = SubnetT{}
@@ -132,7 +137,7 @@ func scanner() {
 				prefix, err := netip.ParsePrefix(v)
 				if err != nil {
 					log.Printf("Error: %s", err)
-				continue
+					return
 				}
 				prefix = prefix.Masked()
 				addr := prefix.Addr()
@@ -188,9 +193,14 @@ func scanner() {
 
 					addr = addr.Next()
 				}
+				mutex.Lock()
 				p.Subnets[v] = persistenceSubnet
+				mutex.Unlock()
+				log.Printf("Scan of %s finished", v)
+			}(subnet)
 		}
-		log.Printf("Scan finished")
+		wg.Wait()
+		log.Printf("All scans finished")
 		f, err := os.Create(conf.PersistenceLocation)
 		if err != nil {
 			log.Printf("Failed to save persistence: %s", err)