From dc454a657f57a5cf143fddc5c1dd87a510c1790a Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 8 Mar 2022 23:05:39 +0100 Subject: nfct: remove lazy binding Since cd5135377ac4 ("conntrackd: cthelper: Set up userspace helpers when daemon starts"), userspace conntrack helpers do not depend on a previous invocation of nfct to set up the userspace helpers. Move helper definitions to nfct-extensions/helper.c since existing deployments might still invoke nfct, even if not required anymore. This patch was motivated by the removal of the lazy binding. Phil Sutter says: "For security purposes, distributions might want to pass -Wl,-z,now linker flags to all builds, thereby disabling lazy binding globally. In the past, nfct relied upon lazy binding: It uses the helper objects' parsing functions without but doesn't provide all symbols the objects use." Acked-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- src/Makefile.am | 2 - src/helpers.c | 3 +- src/helpers/Makefile.am | 2 +- src/helpers/ftp.c | 12 +-- src/helpers/rpc.c | 13 +-- src/helpers/sane.c | 10 +-- src/helpers/tns.c | 7 +- src/nfct-extensions/helper.c | 184 ++++++++++++++++++++++++++++++++++++++++++- 8 files changed, 191 insertions(+), 42 deletions(-) (limited to 'src') diff --git a/src/Makefile.am b/src/Makefile.am index 1d56394..a1a91a0 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -35,8 +35,6 @@ if HAVE_CTHELPER nfct_LDADD += ${LIBNETFILTER_CTHELPER_LIBS} endif -nfct_LDFLAGS = -export-dynamic ${LAZY_LDFLAGS} - conntrackd_SOURCES = alarm.c main.c run.c hash.c queue.c queue_tx.c rbtree.c \ local.c log.c mcast.c udp.c netlink.c vector.c \ filter.c fds.c event.c process.c origin.c date.c \ diff --git a/src/helpers.c b/src/helpers.c index 3e4e6c8..8ca78dc 100644 --- a/src/helpers.c +++ b/src/helpers.c @@ -26,8 +26,7 @@ void helper_register(struct ctd_helper *helper) list_add(&helper->head, &helper_list); } -static struct ctd_helper * -__helper_find(const char *helper_name, uint8_t l4proto) +struct ctd_helper *__helper_find(const char *helper_name, uint8_t l4proto) { struct ctd_helper *cur, *helper = NULL; diff --git a/src/helpers/Makefile.am b/src/helpers/Makefile.am index e4f10c9..e458ab4 100644 --- a/src/helpers/Makefile.am +++ b/src/helpers/Makefile.am @@ -11,7 +11,7 @@ pkglib_LTLIBRARIES = ct_helper_amanda.la \ ct_helper_slp.la \ ct_helper_ssdp.la -HELPER_LDFLAGS = -avoid-version -module $(LIBNETFILTER_CONNTRACK_LIBS) $(LAZY_LDFLAGS) +HELPER_LDFLAGS = -avoid-version -module $(LIBNETFILTER_CONNTRACK_LIBS) HELPER_CFLAGS = $(AM_CFLAGS) $(LIBNETFILTER_CONNTRACK_CFLAGS) ct_helper_amanda_la_SOURCES = amanda.c diff --git a/src/helpers/ftp.c b/src/helpers/ftp.c index 2505c71..29ac55c 100644 --- a/src/helpers/ftp.c +++ b/src/helpers/ftp.c @@ -36,17 +36,9 @@ #include #include -static bool loose; /* XXX: export this as config option. */ - -#define NUM_SEQ_TO_REMEMBER 2 +#include "helpers/ftp.h" -/* This structure exists only once per master */ -struct ftp_info { - /* Valid seq positions for cmd matching after newline */ - uint32_t seq_aft_nl[MYCT_DIR_MAX][NUM_SEQ_TO_REMEMBER]; - /* 0 means seq_match_aft_nl not set */ - int seq_aft_nl_num[MYCT_DIR_MAX]; -}; +static bool loose; /* XXX: export this as config option. */ enum nf_ct_ftp_type { /* PORT command from client */ diff --git a/src/helpers/rpc.c b/src/helpers/rpc.c index 3b3d0a7..732e9ba 100644 --- a/src/helpers/rpc.c +++ b/src/helpers/rpc.c @@ -41,21 +41,12 @@ #include #include +#include "helpers/rpc.h" + /* RFC 1050: RPC: Remote Procedure Call Protocol Specification Version 2 */ /* RFC 1014: XDR: External Data Representation Standard */ #define SUPPORTED_RPC_VERSION 2 -struct rpc_info { - /* XID */ - uint32_t xid; - /* program */ - uint32_t pm_prog; - /* program version */ - uint32_t pm_vers; - /* transport protocol: TCP|UDP */ - uint32_t pm_prot; -}; - /* So, this packet has hit the connection tracking matching code. Mangle it, and change the expectation to match the new version. */ static unsigned int diff --git a/src/helpers/sane.c b/src/helpers/sane.c index 2c07099..ebcb24c 100644 --- a/src/helpers/sane.c +++ b/src/helpers/sane.c @@ -39,11 +39,7 @@ #include #include #include - -enum sane_state { - SANE_STATE_NORMAL, - SANE_STATE_START_REQUESTED, -}; +#include "helpers/sane.h" struct sane_request { uint32_t RPC_code; @@ -61,10 +57,6 @@ struct sane_reply_net_start { /* other fields aren't interesting for conntrack */ }; -struct nf_ct_sane_master { - enum sane_state state; -}; - static int sane_helper_cb(struct pkt_buff *pkt, uint32_t protoff, struct myct *myct, uint32_t ctinfo) diff --git a/src/helpers/tns.c b/src/helpers/tns.c index 803f40a..5692f29 100644 --- a/src/helpers/tns.c +++ b/src/helpers/tns.c @@ -29,6 +29,8 @@ #include #include +#include "helpers/tns.h" + /* TNS SQL*Net Version 2 */ enum tns_types { TNS_TYPE_CONNECT = 1, @@ -58,11 +60,6 @@ struct tns_redirect { uint16_t data_len; }; -struct tns_info { - /* Scan next DATA|REDIRECT packet */ - bool parse; -}; - static int try_number(const char *data, size_t dlen, uint32_t array[], int array_size, char sep, char term) { diff --git a/src/nfct-extensions/helper.c b/src/nfct-extensions/helper.c index e5d8d0a..894bf26 100644 --- a/src/nfct-extensions/helper.c +++ b/src/nfct-extensions/helper.c @@ -180,7 +180,7 @@ static int nfct_cmd_helper_add(struct mnl_socket *nl, int argc, char *argv[]) return -1; } - helper = helper_find(CONNTRACKD_LIB_DIR, argv[3], l4proto, RTLD_LAZY); + helper = __helper_find(argv[3], l4proto); if (helper == NULL) { nfct_perror("that helper is not supported"); return -1; @@ -430,7 +430,7 @@ nfct_cmd_helper_disable(struct mnl_socket *nl, int argc, char *argv[]) return -1; } - helper = helper_find(CONNTRACKD_LIB_DIR, argv[3], l4proto, RTLD_LAZY); + helper = __helper_find(argv[3], l4proto); if (helper == NULL) { nfct_perror("that helper is not supported"); return -1; @@ -468,7 +468,187 @@ static struct nfct_extension helper = { .parse_params = nfct_helper_parse_params, }; +/* + * supported helpers: to set up helpers via nfct, the following definitions are + * provided for backward compatibility reasons since conntrackd does not depend + * on nfct anymore to set up the userspace helpers. + */ + +static struct ctd_helper amanda_helper = { + .name = "amanda", + .l4proto = IPPROTO_UDP, + .policy = { + [0] = { + .name = "amanda", + .expect_max = 3, + .expect_timeout = 180, + }, + }, +}; + +static struct ctd_helper dhcpv6_helper = { + .name = "dhcpv6", + .l4proto = IPPROTO_UDP, + .policy = { + [0] = { + .name = "dhcpv6", + .expect_max = 1, + .expect_timeout = 300, + }, + }, +}; + +#include "helpers/ftp.h" + +static struct ctd_helper ftp_helper = { + .name = "ftp", + .l4proto = IPPROTO_TCP, + .priv_data_len = sizeof(struct ftp_info), + .policy = { + [0] = { + .name = "ftp", + .expect_max = 1, + .expect_timeout = 300, + }, + }, +}; + +static struct ctd_helper mdns_helper = { + .name = "mdns", + .l4proto = IPPROTO_UDP, + .priv_data_len = 0, + .policy = { + [0] = { + .name = "mdns", + .expect_max = 8, + .expect_timeout = 30, + }, + }, +}; + +#include "helpers/rpc.h" + +static struct ctd_helper rpc_helper_tcp = { + .name = "rpc", + .l4proto = IPPROTO_TCP, + .priv_data_len = sizeof(struct rpc_info), + .policy = { + { + .name = "rpc", + .expect_max = 1, + .expect_timeout = 300, + }, + }, +}; + +static struct ctd_helper rpc_helper_udp = { + .name = "rpc", + .l4proto = IPPROTO_UDP, + .priv_data_len = sizeof(struct rpc_info), + .policy = { + { + .name = "rpc", + .expect_max = 1, + .expect_timeout = 300, + }, + }, +}; + +#include "helpers/sane.h" + +static struct ctd_helper sane_helper = { + .name = "sane", + .l4proto = IPPROTO_TCP, + .priv_data_len = sizeof(struct nf_ct_sane_master), + .policy = { + [0] = { + .name = "sane", + .expect_max = 1, + .expect_timeout = 5 * 60, + }, + }, +}; + +static struct ctd_helper slp_helper = { + .name = "slp", + .l4proto = IPPROTO_UDP, + .priv_data_len = 0, + .policy = { + [0] = { + .name = "slp", + .expect_max = 8, + .expect_timeout = 16, /* default CONFIG_MC_MAX + 1 */ + }, + }, +}; + +static struct ctd_helper ssdp_helper_udp = { + .name = "ssdp", + .l4proto = IPPROTO_UDP, + .priv_data_len = 0, + .policy = { + [0] = { + .name = "ssdp", + .expect_max = 8, + .expect_timeout = 5 * 60, + }, + }, +}; + +static struct ctd_helper ssdp_helper_tcp = { + .name = "ssdp", + .l4proto = IPPROTO_TCP, + .priv_data_len = 0, + .policy = { + [0] = { + .name = "ssdp", + .expect_max = 8, + .expect_timeout = 5 * 60, + }, + }, +}; + +static struct ctd_helper tftp_helper = { + .name = "tftp", + .l4proto = IPPROTO_UDP, + .policy = { + [0] = { + .name = "tftp", + .expect_max = 1, + .expect_timeout = 5 * 60, + }, + }, +}; + +#include "helpers/tns.h" + +static struct ctd_helper tns_helper = { + .name = "tns", + .l4proto = IPPROTO_TCP, + .priv_data_len = sizeof(struct tns_info), + .policy = { + [0] = { + .name = "tns", + .expect_max = 1, + .expect_timeout = 300, + }, + }, +}; + static void __init helper_init(void) { + helper_register(&amanda_helper); + helper_register(&dhcpv6_helper); + helper_register(&ftp_helper); + helper_register(&mdns_helper); + helper_register(&rpc_helper_tcp); + helper_register(&rpc_helper_udp); + helper_register(&sane_helper); + helper_register(&slp_helper); + helper_register(&ssdp_helper_udp); + helper_register(&ssdp_helper_tcp); + helper_register(&tftp_helper); + helper_register(&tns_helper); + nfct_extension_register(&helper); } -- cgit v1.2.3