tftpd: new applet (mostly using existing code for tftp)

function                                             old     new   delta
tftp_protocol                                          -    1173   +1173
tftpd_main                                             -     500    +500
tftp_option_get                                        -     102    +102
packed_usage                                       23650   23662     +12
applet_names                                        1809    1815      +6
applet_main                                         1100    1104      +4
applet_nameofs                                       550     552      +2
tftp_main                                            302     301      -1
get_nport                                             32       -     -32
tftp                                                1172       -   -1172
------------------------------------------------------------------------------
(add/remove: 3/2 grow/shrink: 4/1 up/down: 1799/-1205)        Total: 594 bytes
   text    data     bss     dec     hex filename
 796479     662    7420  804561   c46d1 busybox_old
 797153     662    7420  805235   c4973 busybox_unstripped

1 files changed, 18 insertions, 5 deletions

diff --git a/networking/Config.in b/networking/Config.in
index 3c53c1115..729cca148 100644
--- a/networking/Config.in
+++ b/networking/Config.in
@@ -774,28 +774,41 @@ config TFTP
           is usually used for simple, small transfers such as a root image
           for a network-enabled bootloader.
 
+config TFTPD
+        bool "tftpd"
+        default n
+        help
+          This enables the Trivial File Transfer Protocol server program.
+          It expects that stdin is a datagram socket and a packet
+          is already pending on it. It will exit after one transfer.
+          In other words: it should be run from inetd in nowait mode,
+          or from udpsvd. Example: "udpsvd -E 0 69 tftpd DIR"
+
 config FEATURE_TFTP_GET
         bool "Enable \"get\" command"
         default y
-        depends on TFTP
+        depends on TFTP || TFTPD
         help
           Add support for the GET command within the TFTP client.  This allows
           a client to retrieve a file from a TFTP server.
+          Also enable upload support in tftpd, if tftpd is selected.
 
 config FEATURE_TFTP_PUT
         bool "Enable \"put\" command"
         default y
-        depends on TFTP
+        depends on TFTP || TFTPD
         help
           Add support for the PUT command within the TFTP client.  This allows
           a client to transfer a file to a TFTP server.
+          Also enable download support in tftpd, if tftpd is selected.
 
 config FEATURE_TFTP_BLOCKSIZE
-        bool "Enable \"blocksize\" command"
+        bool "Enable \"blksize\" protocol option"
         default n
-        depends on TFTP
+        depends on TFTP || TFTPD
         help
-          Allow the client to specify the desired block size for transfers.
+          Allow tftp to specify block size, and tftpd to understand
+          "blksize" option.
 
 config DEBUG_TFTP
         bool "Enable debug"