piframe-go/cmd/wifi/wifi.go

124 lines
4.1 KiB
Go

package main
import (
"io/ioutil"
"log"
"os"
"os/exec"
"strings"
)
// Various commands that we need for this process
const (
CMD_BLKID = "/usr/sbin/blkid"
CMD_FINDMNT = "/usr/bin/findmnt"
CMD_MOUNT = "/usr/bin/mount"
CMD_NMCLI = "/usr/bin/nmcli"
CMD_UMOUNT = "/usr/bin/umount"
)
// Various file paths we need
const (
MOUNTPOINT = "/var/wifi"
CONFIG_FILE = "wifi.txt"
CONFIG_PATH_FULL = MOUNTPOINT + "/" + CONFIG_FILE
)
func main() {
// Check if mountpoint exists and create if it doesn't
if _, err := os.Stat(MOUNTPOINT); os.IsNotExist(err) {
if err := os.Mkdir(MOUNTPOINT, 0755); err != nil {
log.Fatalf("Could not create mountpoint %s : %s ", MOUNTPOINT, err)
}
}
// Find all blkids that we need to evaluate for wifi config
blkidOut, err := exec.Command(CMD_BLKID, "-o", "device").Output()
if err != nil {
log.Fatalf("Error running %s : %s", CMD_BLKID, err)
}
blkids := string(blkidOut)
// Check blkids to see if they are already mounted
// skip if mounted, skip zram (never mounted) as well
for _, blkid := range strings.Split(strings.TrimSuffix(blkids, "\n"), "\n") {
if blkid == "" || strings.Contains(blkid, "zram") {
continue
}
// SKIP err check here, findmnt will exit w/ status 1 if it's not mounted
// We obviously don't care if it can't find a mountpoint, that's the intent here
findmntOut, _ := exec.Command(CMD_FINDMNT, "-n", "-o", "TARGET", blkid).Output()
mnt := strings.Trim(string(findmntOut), "\n")
if mnt == "" {
// Mount the unmounted volume
err := exec.Command(CMD_MOUNT, blkid, MOUNTPOINT).Run()
if err != nil {
log.Fatalf("Could not mount %s : %s", blkid, err)
}
// Check if the wifi config exists at the new mountpoint, we don't care if it's not present so just keep going
if _, err := os.Stat(CONFIG_PATH_FULL); os.IsNotExist(err) {
if err != nil {
log.Println("WiFi config not found")
err := exec.Command(CMD_UMOUNT, MOUNTPOINT).Run()
if err != nil {
log.Fatalf("Could not unmount %s : %s ", MOUNTPOINT, err)
}
continue
}
}
// Sanity check config file
stat, err := os.Stat(CONFIG_PATH_FULL)
if err != nil {
log.Fatalf("Error getting config file information : %s", err)
}
if stat.Size() > 100000 {
log.Fatal("Config is >100kb, cannot process")
}
if !stat.Mode().IsRegular() {
log.Fatal("Config is NOT a regular (TEXT) file, cannot process")
}
// Open and read wifi config file
configFileContents, err := ioutil.ReadFile(CONFIG_PATH_FULL)
if err != nil {
log.Fatalf("Error reading file %s : %s", CONFIG_PATH_FULL, err)
}
config := strings.Split(strings.Trim(string(configFileContents), "\n"), "\n")
// Final sanity checks
if len(config) != 2 {
log.Fatal("Config has incorrect number of lines, it should only be 2 lines")
}
// Doing stuff with the file contents goes here
essid := config[0]
password := config[1]
log.Printf("Using config: %s / %s for WiFi\n", essid, password)
// Cleanup existing WiFi connections
nmcliOut, err := exec.Command(CMD_NMCLI, "-t", "connection", "show").Output()
if err != nil {
log.Fatalf("Error running %s : %s", CMD_NMCLI, err)
}
connections := strings.Split(strings.Trim(string(nmcliOut), "\n"), "\n")
for _, connection := range connections {
details := strings.Split(connection, ":")
if details[2] != "802-11-wireless" {
continue
}
log.Printf("Cleaning up WiFi connection %s", details[0])
err := exec.Command(CMD_NMCLI, "connection", "del", details[1]).Run()
if err != nil {
log.Fatalf("Error running %s : %s", CMD_NMCLI, err)
}
}
// Create new WiFi connection with network manager
log.Printf("Connecting to %s with password %s\n", essid, password)
err = exec.Command(CMD_NMCLI, "d", "wifi", "connect", essid, "password", password).Run()
if err != nil {
log.Fatalf("Error running %s : %s", CMD_NMCLI, err)
}
// Unmount the filesystem and continue
err = exec.Command(CMD_UMOUNT, MOUNTPOINT).Run()
if err != nil {
log.Fatalf("Could not unmount %s : %s ", MOUNTPOINT, err)
}
}
}
}