diff options
| -rw-r--r-- | net/ipv4/netfilter/nf_nat_ftp.c | 105 |
1 files changed, 35 insertions, 70 deletions
diff --git a/net/ipv4/netfilter/nf_nat_ftp.c b/net/ipv4/netfilter/nf_nat_ftp.c index a1d5d58a58b..86e0e84ff0a 100644 --- a/net/ipv4/netfilter/nf_nat_ftp.c +++ b/net/ipv4/netfilter/nf_nat_ftp.c @@ -27,76 +27,29 @@ MODULE_ALIAS("ip_nat_ftp"); /* FIXME: Time out? --RR */ -static int -mangle_rfc959_packet(struct sk_buff *skb, - __be32 newip, - u_int16_t port, - unsigned int matchoff, - unsigned int matchlen, - struct nf_conn *ct, - enum ip_conntrack_info ctinfo) +static int nf_nat_ftp_fmt_cmd(enum nf_ct_ftp_type type, + char *buffer, size_t buflen, + __be32 addr, u16 port) { - char buffer[sizeof("nnn,nnn,nnn,nnn,nnn,nnn")]; - - sprintf(buffer, "%u,%u,%u,%u,%u,%u", - NIPQUAD(newip), port>>8, port&0xFF); - - pr_debug("calling nf_nat_mangle_tcp_packet\n"); - - return nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff, - matchlen, buffer, strlen(buffer)); -} - -/* |1|132.235.1.2|6275| */ -static int -mangle_eprt_packet(struct sk_buff *skb, - __be32 newip, - u_int16_t port, - unsigned int matchoff, - unsigned int matchlen, - struct nf_conn *ct, - enum ip_conntrack_info ctinfo) -{ - char buffer[sizeof("|1|255.255.255.255|65535|")]; - - sprintf(buffer, "|1|%u.%u.%u.%u|%u|", NIPQUAD(newip), port); - - pr_debug("calling nf_nat_mangle_tcp_packet\n"); - - return nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff, - matchlen, buffer, strlen(buffer)); -} - -/* |1|132.235.1.2|6275| */ -static int -mangle_epsv_packet(struct sk_buff *skb, - __be32 newip, - u_int16_t port, - unsigned int matchoff, - unsigned int matchlen, - struct nf_conn *ct, - enum ip_conntrack_info ctinfo) -{ - char buffer[sizeof("|||65535|")]; - - sprintf(buffer, "|||%u|", port); - - pr_debug("calling nf_nat_mangle_tcp_packet\n"); + switch (type) { + case NF_CT_FTP_PORT: + case NF_CT_FTP_PASV: + return snprintf(buffer, buflen, "%u,%u,%u,%u,%u,%u", + ((unsigned char *)&addr)[0], + ((unsigned char *)&addr)[1], + ((unsigned char *)&addr)[2], + ((unsigned char *)&addr)[3], + port >> 8, + port & 0xFF); + case NF_CT_FTP_EPRT: + return snprintf(buffer, buflen, "|1|%pI4|%u|", &addr, port); + case NF_CT_FTP_EPSV: + return snprintf(buffer, buflen, "|||%u|", port); + } - return nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff, - matchlen, buffer, strlen(buffer)); + return 0; } -static int (*mangle[])(struct sk_buff *, __be32, u_int16_t, - unsigned int, unsigned int, struct nf_conn *, - enum ip_conntrack_info) -= { - [NF_CT_FTP_PORT] = mangle_rfc959_packet, - [NF_CT_FTP_PASV] = mangle_rfc959_packet, - [NF_CT_FTP_EPRT] = mangle_eprt_packet, - [NF_CT_FTP_EPSV] = mangle_epsv_packet -}; - /* So, this packet has hit the connection tracking matching code. Mangle it, and change the expectation to match the new version. */ static unsigned int nf_nat_ftp(struct sk_buff *skb, @@ -110,6 +63,8 @@ static unsigned int nf_nat_ftp(struct sk_buff *skb, u_int16_t port; int dir = CTINFO2DIR(ctinfo); struct nf_conn *ct = exp->master; + char buffer[sizeof("|1|255.255.255.255|65535|")]; + unsigned int buflen; pr_debug("FTP_NAT: type %i, off %u len %u\n", type, matchoff, matchlen); @@ -132,11 +87,21 @@ static unsigned int nf_nat_ftp(struct sk_buff *skb, if (port == 0) return NF_DROP; - if (!mangle[type](skb, newip, port, matchoff, matchlen, ct, ctinfo)) { - nf_ct_unexpect_related(exp); - return NF_DROP; - } + buflen = nf_nat_ftp_fmt_cmd(type, buffer, sizeof(buffer), newip, port); + if (!buflen) + goto out; + + pr_debug("calling nf_nat_mangle_tcp_packet\n"); + + if (!nf_nat_mangle_tcp_packet(skb, ct, ctinfo, matchoff, + matchlen, buffer, buflen)) + goto out; + return NF_ACCEPT; + +out: + nf_ct_unexpect_related(exp); + return NF_DROP; } static void __exit nf_nat_ftp_fini(void) |