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authorDenis Vlasenko2009-03-18 17:32:44 +0000
committerDenis Vlasenko2009-03-18 17:32:44 +0000
commit9f57cf6604638f14390effa01b51c8ad979f14cd (patch)
tree713ecefd47867bb5d2b16c4ae3e5acd28c1c90e3 /networking
parentfce4a9454c5399c2ce8ca8e87048331c6e3d98fa (diff)
downloadbusybox-9f57cf6604638f14390effa01b51c8ad979f14cd.zip
busybox-9f57cf6604638f14390effa01b51c8ad979f14cd.tar.gz
ftpd: fix command fetching to not do it in 1-byte reads;
fix command de-escaping. Tested to download files with embeeded \xff and LF. libbb: tweaks for the above function old new delta ftpd_main 2231 2321 +90 xmalloc_fgets_internal 190 222 +32 xmalloc_fgets_str_len - 27 +27 xmalloc_fgets_str 7 23 +16 xmalloc_fgetline_str 10 26 +16 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 4/0 up/down: 181/0) Total: 181 bytes
Diffstat (limited to 'networking')
-rw-r--r--networking/ftpd.c65
1 files changed, 51 insertions, 14 deletions
diff --git a/networking/ftpd.c b/networking/ftpd.c
index 6630db7..39a4d18 100644
--- a/networking/ftpd.c
+++ b/networking/ftpd.c
@@ -972,23 +972,60 @@ cmdio_get_cmd_and_arg(void)
free(G.ftp_cmd);
len = 8 * 1024; /* Paranoia. Peer may send 1 gigabyte long cmd... */
- G.ftp_cmd = cmd = xmalloc_reads(STDIN_FILENO, NULL, &len);
+ G.ftp_cmd = cmd = xmalloc_fgets_str_len(stdin, "\r\n", &len);
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')
- cmd[len--] = '\0';
+ /* De-escape telnet: 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. */
+ /* Then de-escape FTP: NUL => '\n' */
+ /* Testing for \xff:
+ * Create file named '\xff': echo Hello >`echo -ne "\xff"`
+ * Try to get it: ftpget -v 127.0.0.1 Eff `echo -ne "\xff\xff"`
+ * (need "\xff\xff" until ftpget applet is fixed to do escaping :)
+ * Testing for embedded LF:
+ * LF_HERE=`echo -ne "LF\nHERE"`
+ * echo Hello >"$LF_HERE"
+ * ftpget -v 127.0.0.1 LF_HERE "$LF_HERE"
+ */
+ {
+ int dst, src;
+
+ /* Strip "\r\n" if it is there */
+ if (len != 0 && cmd[len - 1] == '\n') {
+ len--;
+ if (len != 0 && cmd[len - 1] == '\r')
+ len--;
+ cmd[len] = '\0';
+ }
+ src = strchrnul(cmd, 0xff) - cmd;
+ /* 99,99% there are neither NULs nor 255s and src == len */
+ if (src < len) {
+ dst = src;
+ do {
+ if ((unsigned char)(cmd[src]) == 255) {
+ src++;
+ /* 255,xxx - skip 255 */
+ if ((unsigned char)(cmd[src]) != 255) {
+ /* 255,!255 - skip both */
+ src++;
+ continue;
+ }
+ /* 255,255 - retain one 255 */
+ }
+ /* NUL => '\n' */
+ cmd[dst++] = cmd[src] ? cmd[src] : '\n';
+ src++;
+ } while (src < len);
+ cmd[dst] = '\0';
+ }
+ }
if (G.verbose > 1)
verbose_log(cmd);