From b7a396b70015a0820ad486a57935a5cb1c46850a Mon Sep 17 00:00:00 2001 From: Mikhail Sennikovsky Date: Tue, 8 Mar 2022 08:54:31 +0100 Subject: conntrack: use libmnl for updating conntrack table Use libmnl and libnetfilter_conntrack mnl helpers to update the conntrack table entries. Signed-off-by: Mikhail Sennikovsky Signed-off-by: Pablo Neira Ayuso --- src/conntrack.c | 104 +++++++++++++++++++++++++++++++++----------------------- 1 file changed, 61 insertions(+), 43 deletions(-) diff --git a/src/conntrack.c b/src/conntrack.c index 0da2758..d073453 100644 --- a/src/conntrack.c +++ b/src/conntrack.c @@ -68,10 +68,13 @@ #include #include -static struct nfct_mnl_socket { +struct nfct_mnl_socket { struct mnl_socket *mnl; uint32_t portid; -} _sock; +}; + +static struct nfct_mnl_socket _sock; +static struct nfct_mnl_socket _modifier_sock; struct u32_mask { uint32_t value; @@ -2073,13 +2076,18 @@ done: return NFCT_CB_CONTINUE; } -static int print_cb(enum nf_conntrack_msg_type type, - struct nf_conntrack *ct, - void *data) +static int mnl_nfct_print_cb(const struct nlmsghdr *nlh, void *data) { - char buf[1024]; unsigned int op_type = NFCT_O_DEFAULT; unsigned int op_flags = 0; + struct nf_conntrack *ct; + char buf[1024]; + + ct = nfct_new(); + if (ct == NULL) + return MNL_CB_OK; + + nfct_nlmsg_parse(nlh, ct); if (output_mask & _O_SAVE) { ct_save_snprintf(buf, sizeof(buf), ct, labelmap, NFCT_T_NEW); @@ -2097,7 +2105,9 @@ static int print_cb(enum nf_conntrack_msg_type type, done: printf("%s\n", buf); - return NFCT_CB_CONTINUE; + nfct_destroy(ct); + + return MNL_CB_OK; } static void copy_mark(const struct ct_cmd *cmd, struct nf_conntrack *tmp, @@ -2190,29 +2200,38 @@ static void copy_label(const struct ct_cmd *cmd, struct nf_conntrack *tmp, } } -static int update_cb(enum nf_conntrack_msg_type type, - struct nf_conntrack *ct, - void *data) +static int nfct_mnl_request(struct nfct_mnl_socket *sock, uint16_t subsys, + int family, uint16_t type, uint16_t flags, + mnl_cb_t cb, const struct nf_conntrack *ct); + +static int mnl_nfct_update_cb(const struct nlmsghdr *nlh, void *data) { struct ct_cmd *cmd = data; - struct nf_conntrack *obj = cmd->tmpl.ct, *tmp; + struct nfct_mnl_socket *modifier_sock = &_modifier_sock; + struct nf_conntrack *ct, *obj = cmd->tmpl.ct, *tmp = NULL; int res; + ct = nfct_new(); + if (ct == NULL) + return MNL_CB_OK; + + nfct_nlmsg_parse(nlh, ct); + if (filter_nat(cmd, ct) || filter_label(ct, cur_tmpl) || filter_network(cmd, ct)) - return NFCT_CB_CONTINUE; + goto destroy_ok; if (nfct_attr_is_set(obj, ATTR_ID) && nfct_attr_is_set(ct, ATTR_ID) && nfct_get_attr_u32(obj, ATTR_ID) != nfct_get_attr_u32(ct, ATTR_ID)) - return NFCT_CB_CONTINUE; + goto destroy_ok; if (cmd->options & CT_OPT_TUPLE_ORIG && !nfct_cmp(obj, ct, NFCT_CMP_ORIG)) - return NFCT_CB_CONTINUE; + goto destroy_ok; if (cmd->options & CT_OPT_TUPLE_REPL && !nfct_cmp(obj, ct, NFCT_CMP_REPL)) - return NFCT_CB_CONTINUE; + goto destroy_ok; tmp = nfct_new(); if (tmp == NULL) @@ -2225,36 +2244,36 @@ static int update_cb(enum nf_conntrack_msg_type type, copy_label(cmd, tmp, ct, cur_tmpl); /* do not send NFCT_Q_UPDATE if ct appears unchanged */ - if (nfct_cmp(tmp, ct, NFCT_CMP_ALL | NFCT_CMP_MASK)) { - nfct_destroy(tmp); - return NFCT_CB_CONTINUE; - } + if (nfct_cmp(tmp, ct, NFCT_CMP_ALL | NFCT_CMP_MASK)) + goto destroy_ok; - res = nfct_query(ith, NFCT_Q_UPDATE, tmp); - if (res < 0) - fprintf(stderr, - "Operation failed: %s\n", - err2str(errno, CT_UPDATE)); - nfct_callback_register(ith, NFCT_T_ALL, print_cb, NULL); + res = nfct_mnl_request(modifier_sock, NFNL_SUBSYS_CTNETLINK, cmd->family, + IPCTNL_MSG_CT_NEW, NLM_F_ACK, NULL, tmp); + if (res < 0) { + fprintf(stderr, "Operation failed: %s\n", + err2str(errno, CT_UPDATE)); + } - res = nfct_query(ith, NFCT_Q_GET, tmp); + res = nfct_mnl_request(modifier_sock, NFNL_SUBSYS_CTNETLINK, cmd->family, + IPCTNL_MSG_CT_GET, NLM_F_ACK, + mnl_nfct_print_cb, tmp); if (res < 0) { - nfct_destroy(tmp); /* the entry has vanish in middle of the update */ - if (errno == ENOENT) { - nfct_callback_unregister(ith); - return NFCT_CB_CONTINUE; - } + if (errno == ENOENT) + goto destroy_ok; exit_error(OTHER_PROBLEM, "Operation failed: %s", err2str(errno, CT_UPDATE)); } - nfct_destroy(tmp); - nfct_callback_unregister(ith); counter++; - return NFCT_CB_CONTINUE; +destroy_ok: + if (tmp) + nfct_destroy(tmp); + nfct_destroy(ct); + + return MNL_CB_OK; } static int dump_exp_cb(enum nf_conntrack_msg_type type, @@ -3240,6 +3259,7 @@ static void do_parse(struct ct_cmd *ct_cmd, int argc, char *argv[]) static int do_command_ct(const char *progname, struct ct_cmd *cmd) { + struct nfct_mnl_socket *modifier_sock = &_modifier_sock; struct nfct_mnl_socket *sock = &_sock; struct nfct_filter_dump *filter_dump; int res = 0; @@ -3363,19 +3383,17 @@ static int do_command_ct(const char *progname, struct ct_cmd *cmd) break; case CT_UPDATE: - cth = nfct_open(CONNTRACK, 0); - /* internal handler for delete_cb, otherwise we hit EILSEQ */ - ith = nfct_open(CONNTRACK, 0); - if (!cth || !ith) + if (nfct_mnl_socket_open(sock, 0) < 0 || + nfct_mnl_socket_open(modifier_sock, 0) < 0) exit_error(OTHER_PROBLEM, "Can't open handler"); nfct_filter_init(cmd); + res = nfct_mnl_dump(sock, NFNL_SUBSYS_CTNETLINK, + IPCTNL_MSG_CT_GET, mnl_nfct_update_cb, + cmd, NULL); - nfct_callback_register(cth, NFCT_T_ALL, update_cb, cmd); - - res = nfct_query(cth, NFCT_Q_DUMP, &cmd->family); - nfct_close(ith); - nfct_close(cth); + nfct_mnl_socket_close(modifier_sock); + nfct_mnl_socket_close(sock); break; case CT_DELETE: -- cgit v1.2.3