diff --git a/include/linux/netfilter/nf_conntrack_ftp.h b/include/linux/netfilter/nf_conntrack_ftp.h index 28f18df3652..8faf3f792d1 100644 --- a/include/linux/netfilter/nf_conntrack_ftp.h +++ b/include/linux/netfilter/nf_conntrack_ftp.h @@ -18,13 +18,17 @@ enum nf_ct_ftp_type { #define FTP_PORT 21 +#define NF_CT_FTP_SEQ_PICKUP (1 << 0) + #define NUM_SEQ_TO_REMEMBER 2 /* This structure exists only once per master */ struct nf_ct_ftp_master { /* Valid seq positions for cmd matching after newline */ u_int32_t seq_aft_nl[IP_CT_DIR_MAX][NUM_SEQ_TO_REMEMBER]; /* 0 means seq_match_aft_nl not set */ - int seq_aft_nl_num[IP_CT_DIR_MAX]; + u_int16_t seq_aft_nl_num[IP_CT_DIR_MAX]; + /* pickup sequence tracking, useful for conntrackd */ + u_int16_t flags[IP_CT_DIR_MAX]; }; struct nf_conntrack_expect; diff --git a/net/netfilter/nf_conntrack_ftp.c b/net/netfilter/nf_conntrack_ftp.c index f8cc26ad445..1ce3befb7c8 100644 --- a/net/netfilter/nf_conntrack_ftp.c +++ b/net/netfilter/nf_conntrack_ftp.c @@ -396,6 +396,12 @@ static int help(struct sk_buff *skb, /* Look up to see if we're just after a \n. */ if (!find_nl_seq(ntohl(th->seq), ct_ftp_info, dir)) { + /* We're picking up this, clear flags and let it continue */ + if (unlikely(ct_ftp_info->flags[dir] & NF_CT_FTP_SEQ_PICKUP)) { + ct_ftp_info->flags[dir] ^= NF_CT_FTP_SEQ_PICKUP; + goto skip_nl_seq; + } + /* Now if this ends in \n, update ftp info. */ pr_debug("nf_conntrack_ftp: wrong seq pos %s(%u) or %s(%u)\n", ct_ftp_info->seq_aft_nl_num[dir] > 0 ? "" : "(UNSET)", @@ -406,6 +412,7 @@ static int help(struct sk_buff *skb, goto out_update_nl; } +skip_nl_seq: /* Initialize IP/IPv6 addr to expected address (it's not mentioned in EPSV responses) */ cmd.l3num = nf_ct_l3num(ct); @@ -512,6 +519,19 @@ out_update_nl: return ret; } +static int nf_ct_ftp_from_nlattr(struct nlattr *attr, struct nf_conn *ct) +{ + struct nf_ct_ftp_master *ftp = nfct_help_data(ct); + + /* This conntrack has been injected from user-space, always pick up + * sequence tracking. Otherwise, the first FTP command after the + * failover breaks. + */ + ftp->flags[IP_CT_DIR_ORIGINAL] |= NF_CT_FTP_SEQ_PICKUP; + ftp->flags[IP_CT_DIR_REPLY] |= NF_CT_FTP_SEQ_PICKUP; + return 0; +} + static struct nf_conntrack_helper ftp[MAX_PORTS][2] __read_mostly; static const struct nf_conntrack_expect_policy ftp_exp_policy = { @@ -561,6 +581,7 @@ static int __init nf_conntrack_ftp_init(void) ftp[i][j].expect_policy = &ftp_exp_policy; ftp[i][j].me = THIS_MODULE; ftp[i][j].help = help; + ftp[i][j].from_nlattr = nf_ct_ftp_from_nlattr; if (ports[i] == FTP_PORT) sprintf(ftp[i][j].name, "ftp"); else diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 2dcd080b8c4..7bbfb3deea3 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -1238,7 +1238,7 @@ ctnetlink_change_helper(struct nf_conn *ct, const struct nlattr * const cda[]) if (help) { if (help->helper == helper) { /* update private helper data if allowed. */ - if (helper->from_nlattr && helpinfo) + if (helper->from_nlattr) helper->from_nlattr(helpinfo, ct); return 0; } else @@ -1467,7 +1467,7 @@ ctnetlink_create_conntrack(struct net *net, u16 zone, goto err2; } /* set private helper data if allowed. */ - if (helper->from_nlattr && helpinfo) + if (helper->from_nlattr) helper->from_nlattr(helpinfo, ct); /* not in hash table yet so not strictly necessary */ diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c index 3678073360a..945950a8b1f 100644 --- a/net/netfilter/nfnetlink_cthelper.c +++ b/net/netfilter/nfnetlink_cthelper.c @@ -85,6 +85,9 @@ nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct) { const struct nf_conn_help *help = nfct_help(ct); + if (attr == NULL) + return -EINVAL; + if (help->helper->data_len == 0) return -EINVAL;