No tcpdump installation method in android

Run the mount command mountrootfson/kernel (ro, relatime) tmpfson/devtypetmpfs (rw, relatime, mode755) devptson/dev/ptstypedevpts (rw, relatime, mode600) procon/kernel (rw, rel input the mount command
Mount
Rootfs on/type rootfs (ro, relatime)
Tmpfs on/dev type tmpfs (rw, relatime, mode = 755)
Devpts on/dev/pts type devpts (rw, relatime, model = 600)
Proc on/proc type proc (rw, relatime)
Sysfs on/sys type sysfs (rw, relatime)
Tmpfs on/sqlite_stmt_journals type tmpfs (rw, relatime, size = 4096 k)
None on/dev/cpuctl type cgroup (rw, relatime, cpu)
/Dev/block/mtdblock3 on/system type yaffs2 (ro, relatime)
/Dev/block/mtdblock5 on/data type yaffs2 (rw, nosuid, nodev, relatime)
/Dev/block/mtdblock4 on/cache type yaffs2 (rw, nosuid, nodev, relatime)
/Dev/block // vold/179: 1 on/sdcard type vfat (rw, dirsync, nosuid, nodev, noexec, rela
Time, uid = 1000, gid = 1015, fmask = 0702, dmask = 0702, allow_utime = 0020, codepage = cp437, ioc
Harset = ISO8859-1, shortname = mixed, utf8, errors = remount-ro)
We can see that
/Dev/block/mtdblock3 on/system type yaffs2 (ro, relatime)
Remount the input command
Mount-o remount/dev/block/mtdblock3/system
Input mount again
We can see that
# Mount
Mount
Rootfs on/type rootfs (ro, relatime)
Tmpfs on/dev type tmpfs (rw, relatime, mode = 755)
Devpts on/dev/pts type devpts (rw, relatime, model = 600)
Proc on/proc type proc (rw, relatime)
Sysfs on/sys type sysfs (rw, relatime)
Tmpfs on/sqlite_stmt_journals type tmpfs (rw, relatime, size = 4096 k)
None on/dev/cpuctl type cgroup (rw, relatime, cpu)
/Dev/block/mtdblock3 on/system type yaffs2 (rw, relatime)
/Dev/block/mtdblock5 on/data type yaffs2 (rw, nosuid, nodev, relatime)
/Dev/block/mtdblock4 on/cache type yaffs2 (rw, nosuid, nodev, relatime)
/Dev/block // vold/179: 1 on/sdcard type vfat (rw, dirsync, nosuid, nodev, noexec, rela
Time, uid = 1000, gid = 1015, fmask = 0702, dmask = 0702, allow_utime = 0020, codepage = cp437, ioc
Harset = ISO8859-1, shortname = mixed, utf8, errors = remount-ro)
You can see that/system can be deleted and modified as needed.
Then TcpdumpImport the file to the/system/xbin/directory.
Adb push d:/tcpdump/system/xbin/
Then run the command
# Cd system
Cd system
# Cd xbin
Cd xbin
# Ls
Ls
Tcpdump
#./Tcpdump
./Tcpdump
./Tcpdump: permission denied
# Chmod + x tcpdump
Chmod + x tcpdump
#./Tcpdump
./Tcpdump
Tcpdump: verbose output suppressed, use-v or-vv for fullprotocol decode
Listening on rmnet0, link-type EN10MB (Ethernet), capture size96 bytes
After adding permissions, tcpdump can be used.