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ftpd: add some comments

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This commit is contained in:
Denis Vlasenko 2009-03-18 16:02:54 +00:00
parent e3b840ce98
commit fce4a9454c
1 changed files with 15 additions and 1 deletions
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16
networking/ftpd.c
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@ -702,7 +702,10 @@ handle_dir_common(int opts)
line = xmalloc_fgetline(ls_fp);
if (!line)
break;
cmdio_write(0, line); /* hack: 0 results in no status at all */
/* Hack: 0 results in no status at all */
/* Note: it's ok that we don't prepend space,
* ftp.kernel.org doesn't do that too */
cmdio_write(0, line);
free(line);
}
WRITE_OK(FTP_STATFILE_OK);
@ -973,6 +976,15 @@ cmdio_get_cmd_and_arg(void)
if (!cmd)
exit(0);
/* TODO: de-escape telnet here: 0xff,0xff => 0xff */
/* RFC959 says that ABOR, STAT, QUIT may be sent even during
* data transfer, and may be preceded by telnet's "Interrupt Process"
* code (two-byte sequence 255,244) and then by telnet "Synch" code
* 255,242 (byte 242 is sent with TCP URG bit using send(MSG_OOB)
* and may generate SIGURG on our side. See RFC854).
* So far we don't support that (may install SIGURG handler if we'd want to),
* but we need to at least remove 255,xxx pairs. lftp sends those. */
/* Trailing '\n' is already stripped, strip '\r' */
len = strlen(cmd) - 1;
if ((ssize_t)len >= 0 && cmd[len] == '\r')
@ -1115,6 +1127,8 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv)
/* Set up options on the command socket (do we need these all? why?) */
setsockopt(STDIN_FILENO, IPPROTO_TCP, TCP_NODELAY, &const_int_1, sizeof(const_int_1));
setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
/* Telnet protocol over command link may send "urgent" data,
* we prefer it to be received in the "normal" data stream: */
setsockopt(STDIN_FILENO, SOL_SOCKET, SO_OOBINLINE, &const_int_1, sizeof(const_int_1));
WRITE_OK(FTP_GREET);