diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c index 6b217074237b..b8a0924064ef 100644 --- a/net/netfilter/nf_conntrack_ftp.c +++ b/net/netfilter/nf_conntrack_ftp.c @@ -55,10 +55,14 @@ unsigned int (*nf_nat_ftp_hook)(struct sk_buff *skb, struct nf_conntrack_expect *exp); EXPORT_SYMBOL_GPL(nf_nat_ftp_hook); -static int try_rfc959(const char *, size_t, struct nf_conntrack_man *, char); -static int try_eprt(const char *, size_t, struct nf_conntrack_man *, char); +static int try_rfc959(const char *, size_t, struct nf_conntrack_man *, + char, unsigned int *); +static int try_rfc1123(const char *, size_t, struct nf_conntrack_man *, + char, unsigned int *); +static int try_eprt(const char *, size_t, struct nf_conntrack_man *, + char, unsigned int *); static int try_epsv_response(const char *, size_t, struct nf_conntrack_man *, - char); + char, unsigned int *); static struct ftp_search { const char *pattern; @@ -66,7 +70,7 @@ static struct ftp_search { char skip; char term; enum nf_ct_ftp_type ftptype; - int (*getnum)(const char *, size_t, struct nf_conntrack_man *, char); + int (*getnum)(const char *, size_t, struct nf_conntrack_man *, char, unsigned int *); } search[IP_CT_DIR_MAX][2] = { [IP_CT_DIR_ORIGINAL] = { { @@ -90,10 +94,8 @@ static struct ftp_search { { .pattern = "227 ", .plen = sizeof("227 ") - 1, - .skip = '(', - .term = ')', .ftptype = NF_CT_FTP_PASV, - .getnum = try_rfc959, + .getnum = try_rfc1123, }, { .pattern = "229 ", @@ -132,8 +134,9 @@ static int try_number(const char *data, size_t dlen, u_int32_t array[], i++; else { /* Unexpected character; true if it's the - terminator and we're finished. */ - if (*data == term && i == array_size - 1) + terminator (or we don't care about one) + and we're finished. */ + if ((*data == term || !term) && i == array_size - 1) return len; pr_debug("Char %u (got %u nums) `%u' unexpected\n", @@ -148,7 +151,8 @@ static int try_number(const char *data, size_t dlen, u_int32_t array[], /* Returns 0, or length of numbers: 192,168,1,1,5,6 */ static int try_rfc959(const char *data, size_t dlen, - struct nf_conntrack_man *cmd, char term) + struct nf_conntrack_man *cmd, char term, + unsigned int *offset) { int length; u_int32_t array[6]; @@ -163,6 +167,33 @@ static int try_rfc959(const char *data, size_t dlen, return length; } +/* + * From RFC 1123: + * The format of the 227 reply to a PASV command is not + * well standardized. In particular, an FTP client cannot + * assume that the parentheses shown on page 40 of RFC-959 + * will be present (and in fact, Figure 3 on page 43 omits + * them). Therefore, a User-FTP program that interprets + * the PASV reply must scan the reply for the first digit + * of the host and port numbers. + */ +static int try_rfc1123(const char *data, size_t dlen, + struct nf_conntrack_man *cmd, char term, + unsigned int *offset) +{ + int i; + for (i = 0; i < dlen; i++) + if (isdigit(data[i])) + break; + + if (i == dlen) + return 0; + + *offset += i; + + return try_rfc959(data + i, dlen - i, cmd, 0, offset); +} + /* Grab port: number up to delimiter */ static int get_port(const char *data, int start, size_t dlen, char delim, __be16 *port) @@ -191,7 +222,7 @@ static int get_port(const char *data, int start, size_t dlen, char delim, /* Returns 0, or length of numbers: |1|132.235.1.2|6275| or |2|3ffe::1|6275| */ static int try_eprt(const char *data, size_t dlen, struct nf_conntrack_man *cmd, - char term) + char term, unsigned int *offset) { char delim; int length; @@ -239,7 +270,8 @@ static int try_eprt(const char *data, size_t dlen, struct nf_conntrack_man *cmd, /* Returns 0, or length of numbers: |||6446| */ static int try_epsv_response(const char *data, size_t dlen, - struct nf_conntrack_man *cmd, char term) + struct nf_conntrack_man *cmd, char term, + unsigned int *offset) { char delim; @@ -261,9 +293,10 @@ static int find_pattern(const char *data, size_t dlen, unsigned int *numlen, struct nf_conntrack_man *cmd, int (*getnum)(const char *, size_t, - struct nf_conntrack_man *, char)) + struct nf_conntrack_man *, char, + unsigned int *)) { - size_t i; + size_t i = plen; pr_debug("find_pattern `%s': dlen = %Zu\n", pattern, dlen); if (dlen == 0) @@ -293,16 +326,18 @@ static int find_pattern(const char *data, size_t dlen, pr_debug("Pattern matches!\n"); /* Now we've found the constant string, try to skip to the 'skip' character */ - for (i = plen; data[i] != skip; i++) - if (i == dlen - 1) return -1; + if (skip) { + for (i = plen; data[i] != skip; i++) + if (i == dlen - 1) return -1; - /* Skip over the last character */ - i++; + /* Skip over the last character */ + i++; + } pr_debug("Skipped up to `%c'!\n", skip); *numoff = i; - *numlen = getnum(data + i, dlen - i, cmd, term); + *numlen = getnum(data + i, dlen - i, cmd, term, numoff); if (!*numlen) return -1;