在嵌入式Linux系统中，有时候需要搭建一个ftp服务器，以便windows或linux系统去访问嵌入式linux系统的数据。现在流行的ftp和vsftpd软件相对比较大，在嵌入式Linux系统下不太合适。最近由于需要，发现了一款很小型的ftp服务器，在这里分享。
根据自己的需要，修改Makefile，将gcc修改为交叉工具链的gcc，比如mips-gnu-linux-gcc。
若要静态编译，在CFLAGS后面添加"-static"选项。
以下的Makefile已经修改：
#
#
# Makefile for the linux version of stupid-ftpd
#
#
#
CC=mips-linux-gnu-gcc -EL #修改
OBJS=ftpcommand.o ftpdconfig.o command.o ls.o stupid-ftpd.o
DOBJS=ftpcommand.do ftpdconfig.do command.do ls.do stupid-ftpd.do
POBJS=ftpcommand.po ftpdconfig.po command.po ls.po stupid-ftpd.po
LIBS=
CFLAGS=-O2 -Wall -Wstrict-prototypes -static#修改
DCFLAGS=-g -DDEBUG -Wall -Wstrict-prototypes
PCFLAGS=-g -DDEBUG -Wall -Wstrict-prototypes -Wcast-align -Wwrite-strings -Wconversion -Waggregate-return -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls -Wnested-externs
EXEC=stupid-ftpd.Linux6
.SUFFIXES: .c .o .do .po
all: $(OBJS)
$(CC) $(CFLAGS) -o $(EXEC) $(OBJS) $(LIBS)
debug: $(DOBJS)
$(CC) $(DCFLAGS) -o $(EXEC) $(DOBJS) $(LIBS)
pedantic: $(POBJS)
$(CC) $(PCFLAGS) -o $(EXEC) $(POBJS) $(LIBS)
clean:
rm -f $(OBJS) $(DOBJS) $(POBJS) $(EXEC) *~
.c.o:
$(CC) $(CFLAGS) -c -o $@ $<
.c.do:
$(CC) $(DCFLAGS) -c -o $@ $<
.c.po:
$(CC) $(PCFLAGS) -c -o $@ $<
install:
install -m 755 -s ./stupid-ftpd /usr/local/bin/stupid-ftpd
install -m 700 -d /etc/stupid-ftpd
install -m 755 -d /usr/local/stupid-ftpd
install -m 600 ./stupid-ftpd.conf /etc/stupid-ftpd/stupid-ftpd.conf
只需修改两个位置。
编译完成后，生成stupid-ftpd.Linux6可执行程序，该程序运行需要配置文件，以下的配置已经被修改并验证，是可以用的。但前提是运行在嵌入式Linux系统下，21端口没有被占用。
#
# This is a config-file for stupid-ftpd
# ------------------------------------
#
# The standard path should be /etc/stupid-ftpd.conf
# You can define other paths by using the "-f" option
# when starting stupid-ftpd.
#
#
# ATTENTION: 1) Remember, that the server is running with YOUR permissions.
#It will fail to access other users directory, unless it is
#root, but it also allows to access ALL YOUR directories,
#which are deeper in a user's root-dir and YOU HAVE access to.
#2) To solve the problem, the best way is to define a group-ID
# for stupid-ftpd.
# Or if you aren't root: set the MAIN root (serverroot=) to
# the highest directory depth which is possible.
#3) REMEMBER: DO NOT PUT THIS FILE in an accessible directory!!!
# There are passwords defined here. The safest place is
# outside the serverroot.
# Server operation mode:
# daemon - quiet in background
# interactive - standard mode
#mode=interactive #交互式的形式运行
mode=daemon #以守护进程的形式运行在后台
# chroot to
#serverroot=/usr/home/cinek/tmp3/aaa
serverroot=/mnt #将ftp的根目录设置为/mnt目录下，在windows打开该ftp，就能访问/mnt目录
# type of chroot
# real- kernel chroot(), high security, but needs root privileges
# virtual - no real chroot(), software side (virtual) chroot
#changeroottype=real
changeroottype=virtual
# Port number for the FTP-Protocol
#port=2121
port=21 #默认为ftp的端口号。
# Maximum users allowed to log in
maxusers=10
# Message Of The Day (motd)
# It will be displayed after the login procedure.
#motd=/tmp/stupid-ftpd.motd
# Message on quit
# It will be displayed when quitting.
#byemsg=/tmp/stupid-ftpd.bye
# Log
#log=/tmp/stupid-ftpd.log
# User list:
# Format: user=<login> <passwd> <subdir> <maxlogins> <flags>
# <login> user name
# <passwd>password or * for anonymous access
# <subdir>(internally appended to serverroot)
# the user has access to the WHOLE SUBTREE,
# if the server has access to it
# <maxlogins> maximal logins with this usertype
# <flags> D - download
# U - upload + making directories
# O - overwrite existing files
# M - allows multiple logins
# E - allows erase operations
# A - allows EVERYTHING(!)
#
# user ftp is mapped to user anonymous, don't forget this
#
# Examples:
# user=user1 passx /tmp 2 D
# - login: user1, passwd: passx, max login twice (different IPs!)
#only download rights from directory /tmp
# user=user2 passy /home/user2 0 DU
# - login: user2, passwd: passy, no login count limit (different IPs!)
#download+upload rights to directory /home/user2
# user=user3 passz /home/user3 5 DUOM
# - login: user3, passwd: passz, max login count 5 (even from same IP)
#download+upload+overwrite rights to directory /home/user3
# user=user4 passq /tmp 10 -
# - login: user4, passwd: passq, max login count 10 (even from same IP)
#look-only rights at directory /tmp
#
# SEE: ATTENTION remark on the top of this file !!!
user=anonymous */5 A
# Banned hosts
# "*" and "?" are allowed here
#ban=192.168.*
#ban=localhost
#ban=*.banme.com
# Ban message (displayed to user who is banned)
# Please don't use more than 70 characters.
#banmsg=Go away !
# Login/password timeout
login-timeout=120
# Timeout (while logged in)
timeout=240
剩下的用默认的配置就可以了，特别注意，设置port参数的时候，2121端口不能使用，无法提供ftp服务。要设置为21端口，经过测试，设置为21端口，在Linux的PC机，报错：21端口被占用。但在嵌入式Linux下，是可以使用的。
stupid-ftpd.Linux6的使用方法：
直接用-f选项指定配置文件：
stupid-ftpd.Linux6 -f stupid-ftpd.conf
然后保证windows与嵌入式Linux系统的IP地址在同一网段，然后再"我的电脑"输入：ftp://192.168.x.x/
这里就不截图了。