platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-api/app/transport_bootstrap_bypass_resolve.go

@@ -0,0 +1,137 @@
+package app
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/netip"
+	"net/url"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func transportResolveBootstrapIPv4(candidates []string) ([]string, error) {
+	set := map[string]struct{}{}
+	var warns []string
+
+	for _, raw := range candidates {
+		host := transportNormalizeBootstrapTarget(raw)
+		if host == "" {
+			continue
+		}
+		if addr, err := netip.ParseAddr(host); err == nil {
+			if addr.Is4() {
+				set[addr.String()] = struct{}{}
+			}
+			continue
+		}
+
+		ctx, cancel := context.WithTimeout(context.Background(), 2500*time.Millisecond)
+		ipAddrs, err := net.DefaultResolver.LookupIPAddr(ctx, host)
+		cancel()
+		if err != nil {
+			warns = append(warns, host+": "+strings.TrimSpace(err.Error()))
+			continue
+		}
+		resolved := 0
+		for _, ipa := range ipAddrs {
+			v4 := ipa.IP.To4()
+			if v4 == nil {
+				continue
+			}
+			set[v4.String()] = struct{}{}
+			resolved++
+		}
+		if resolved == 0 {
+			warns = append(warns, host+": no IPv4 records")
+		}
+	}
+
+	ips := make([]string, 0, len(set))
+	for ip := range set {
+		ips = append(ips, ip)
+	}
+	sort.Strings(ips)
+
+	if len(warns) == 0 {
+		return ips, nil
+	}
+	if len(warns) > 3 {
+		warns = append(warns[:3], fmt.Sprintf("... and %d more", len(warns)-3))
+	}
+	return ips, fmt.Errorf("bootstrap resolve warnings: %s", strings.Join(warns, "; "))
+}
+
+func transportNormalizeBootstrapTarget(raw string) string {
+	s := strings.TrimSpace(raw)
+	if s == "" {
+		return ""
+	}
+
+	if strings.Contains(s, "://") {
+		if u, err := url.Parse(s); err == nil {
+			host := strings.TrimSpace(u.Host)
+			if host != "" {
+				s = host
+			} else if strings.TrimSpace(u.Opaque) != "" {
+				s = strings.TrimSpace(u.Opaque)
+			}
+		}
+	}
+
+	if at := strings.LastIndex(s, "@"); at >= 0 {
+		s = s[at+1:]
+	}
+	if idx := strings.IndexAny(s, "/?#"); idx >= 0 {
+		s = s[:idx]
+	}
+	s = strings.TrimSpace(s)
+	if s == "" {
+		return ""
+	}
+
+	if host, _, err := net.SplitHostPort(s); err == nil {
+		s = host
+	} else if strings.Count(s, ":") == 1 {
+		i := strings.LastIndex(s, ":")
+		if i > 0 {
+			if _, err := strconv.Atoi(strings.TrimSpace(s[i+1:])); err == nil {
+				s = s[:i]
+			}
+		}
+	}
+	s = strings.TrimSpace(strings.Trim(s, "[]"))
+	s = strings.TrimSuffix(s, ".")
+	if s == "" {
+		return ""
+	}
+	return strings.ToLower(s)
+}
+
+func transportDetectMainIPv4Route() (transportMainRoute, error) {
+	stdout, stderr, code, err := transportRunCommand(5*time.Second, "ip", "-4", "route", "show", "table", "main", "default")
+	if err != nil || code != 0 {
+		return transportMainRoute{}, transportCommandError("ip -4 route show table main default", stdout, stderr, code, err)
+	}
+	for _, line := range strings.Split(stdout, "\n") {
+		fields := strings.Fields(strings.TrimSpace(line))
+		if len(fields) == 0 || fields[0] != "default" {
+			continue
+		}
+		route := transportMainRoute{}
+		for i := 0; i < len(fields)-1; i++ {
+			switch fields[i] {
+			case "dev":
+				route.Dev = strings.TrimSpace(fields[i+1])
+			case "via":
+				route.Via = strings.TrimSpace(fields[i+1])
+			}
+		}
+		if route.Dev != "" {
+			return route, nil
+		}
+	}
+	return transportMainRoute{}, fmt.Errorf("main default route not found")
+}