cmd: set-bans: allow banning from fpath

e.g., given a `bans.csv`

	104.248.45.80,2400h
	104.248.45.81,2400h
	104.248.45.83,2400h
	104.248.45.84,2400h

one can ban all those 4 hosts via

	$ monero daemon set-bans -f ./bans.csv

Signed-off-by: Ciro S. Costa <utxobr@protonmail.com>

cmd/monero/commands/daemon/set_bans.go

@@ -1,8 +1,10 @@
 package daemon
 
 import (
+	"encoding/csv"
 	"fmt"
 	"net"
+	"os"
 	"time"
 
 	"github.com/spf13/cobra"
@@ -15,6 +17,7 @@ import (
 type setBansCommand struct {
 	Host     net.IP
 	Duration time.Duration
+	Filepath string
 
 	JSON bool
 }
@@ -30,7 +33,10 @@ func (c *setBansCommand) Cmd() *cobra.Command {
 		false, "whether or not to output the result as json")
 	cmd.Flags().IPVar(&c.Host, "host",
 		nil, "ip address (string format) of the host to ban")
-	_ = cmd.MarkFlagRequired("host")
+
+	cmd.Flags().StringVarP(&c.Filepath, "filepath", "f",
+		"", "location of a csv file containing <host>,<period> "+
+			"entries to ban")
 
 	cmd.Flags().DurationVar(&c.Duration, "duration",
 		24*time.Hour, "for how long this host should be banned for")
@@ -48,14 +54,26 @@ func (c *setBansCommand) RunE(_ *cobra.Command, _ []string) error {
 	}
 
 	params := daemon.SetBansRequestParameters{
-		Bans: []daemon.SetBansBan{
-			{
-				Host:    c.Host.String(),
-				Ban:     true,
-				Seconds: int64(c.Duration.Seconds()),
-			},
-		},
+		Bans: []daemon.SetBansBan{},
 	}
+
+	if c.Host != nil {
+		params.Bans = append(params.Bans, daemon.SetBansBan{
+			Host:    c.Host.String(),
+			Ban:     true,
+			Seconds: int64(c.Duration.Seconds()),
+		})
+	}
+
+	if c.Filepath != "" {
+		bansFromFile, err := c.bansFromFilepath()
+		if err != nil {
+			return fmt.Errorf("bans from file: %w", err)
+		}
+
+		params.Bans = append(params.Bans, bansFromFile...)
+	}
+
 	resp, err := client.SetBans(ctx, params)
 	if err != nil {
 		return fmt.Errorf("set bans: %w", err)
@@ -69,6 +87,43 @@ func (c *setBansCommand) RunE(_ *cobra.Command, _ []string) error {
 	return nil
 }
 
+func (c *setBansCommand) bansFromFilepath() ([]daemon.SetBansBan, error) {
+	f, err := os.Open(c.Filepath)
+	if err != nil {
+		return nil, fmt.Errorf("open: %w", err)
+	}
+	defer f.Close()
+
+	entries, err := csv.NewReader(f).ReadAll()
+	if err != nil {
+		return nil, fmt.Errorf("csv read all: %w", err)
+	}
+
+	bans := []daemon.SetBansBan{}
+	for _, entry := range entries {
+		if len(entry) != 2 {
+			return nil, fmt.Errorf(
+				"expected 2 fields in entry, got %d",
+				len(entry),
+			)
+		}
+
+		host, durationStr := entry[0], entry[1]
+		duration, err := time.ParseDuration(durationStr)
+		if err != nil {
+			return nil, fmt.Errorf("parse duration: %w", err)
+		}
+
+		bans = append(bans, daemon.SetBansBan{
+			Host:    host,
+			Seconds: int64(duration.Seconds()),
+			Ban:     true,
+		})
+	}
+
+	return bans, nil
+}
+
 // nolint:forbidigo
 func (c *setBansCommand) pretty(v *daemon.SetBansResult) {
 	fmt.Println(v.Status)