diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/Makefile.am | 9 | ||||
| -rw-r--r-- | src/libnfnetlink.c | 210 |
2 files changed, 167 insertions, 52 deletions
diff --git a/src/Makefile.am b/src/Makefile.am index 16340c5..cbddcb9 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -1,6 +1,6 @@ -#AUTOMAKE_OPTIONS = no-dependencies foreign - -#EXTRA_DIST = $(man_MANS) acinclude.m4 +# This is _NOT_ the library release version, it's an API version. +# Please read Chapter 6 "Library interface versions" of the libtool documentation before making any modification +LIBVERSION=1:0:0 INCLUDES = $(all_includes) -I$(top_srcdir)/include AM_CFLAGS=-fPIC -Wall @@ -8,5 +8,6 @@ LIBS= lib_LTLIBRARIES = libnfnetlink.la -libnfnetlink_la_LDFLAGS = -Wc,-nostartfiles +libnfnetlink_la_LDFLAGS = -Wc,-nostartfiles \ + -version-info $(LIBVERSION) libnfnetlink_la_SOURCES = libnfnetlink.c diff --git a/src/libnfnetlink.c b/src/libnfnetlink.c index 6547987..3f37273 100644 --- a/src/libnfnetlink.c +++ b/src/libnfnetlink.c @@ -1,7 +1,8 @@ /* libnfnetlink.c: generic library for communication with netfilter * - * (C) 2001 by Jay Schulist <jschlst@samba.org> - * (C) 2002-2005 by Harald Welte <laforge@gnumonks.org> + * (C) 2002-2006 by Harald Welte <laforge@gnumonks.org> + * + * Based on some original ideas from Jay Schulist <jschlst@samba.org> * * Development of this code funded by Astaro AG (http://www.astaro.com) * @@ -12,6 +13,9 @@ * Define structure nfnlhdr * Added __be64_to_cpu function * Use NFA_TYPE macro to get the attribute type + * + * 2006-01-14 Harald Welte <laforge@netfilter.org>: + * introduce nfnl_subsys_handle */ #include <stdlib.h> @@ -36,6 +40,26 @@ #define nfnl_debug_dump_packet(a, b, ...) #endif +struct nfnl_subsys_handle { + struct nfnl_handle *nfnlh; + u_int32_t subscriptions; + u_int8_t subsys_id; + u_int8_t cb_count; + struct nfnl_callback *cb; /* array of callbacks */ +}; + +#define NFNL_MAX_SUBSYS 16 /* enough for now */ +struct nfnl_handle { + int fd; + struct sockaddr_nl local; + struct sockaddr_nl peer; + u_int32_t subscriptions; + u_int32_t seq; + u_int32_t dump; + struct nlmsghdr *last_nlhdr; + struct nfnl_subsys_handle subsys[NFNL_MAX_SUBSYS+1]; +}; + void nfnl_dump_packet(struct nlmsghdr *nlh, int received_len, char *desc) { void *nlmsg_data = NLMSG_DATA(nlh); @@ -65,63 +89,131 @@ int nfnl_fd(struct nfnl_handle *h) return h->fd; } +static int recalc_rebind_subscriptions(struct nfnl_handle *nfnlh) +{ + int i; + u_int32_t new_subscriptions = 0; + + for (i = 0; i < NFNL_MAX_SUBSYS; i++) + new_subscriptions |= nfnlh->subsys[i].subscriptions; + + if (nfnlh->subscriptions != new_subscriptions) { + int err; + + nfnlh->local.nl_groups = new_subscriptions; + err = bind(nfnlh->fd, (struct sockaddr *)&nfnlh->local, + sizeof(nfnlh->local)); + if (err < 0) { + nfnl_error("bind(netlink): %s", strerror(errno)); + return err; + } + nfnlh->subscriptions = new_subscriptions; + } + + return 0; +} + /** * nfnl_open - open a netlink socket * * nfnlh: libnfnetlink handle to be allocated by user - * subsys_id: which nfnetlink subsystem we are interested in - * cb_count: number of callbacks that are used maximum. - * subscriptions: netlink groups we want to be subscribed to * */ -int nfnl_open(struct nfnl_handle *nfnlh, u_int8_t subsys_id, - u_int8_t cb_count, u_int32_t subscriptions) +struct nfnl_handle *nfnl_open(void) { - int err; + struct nfnl_handle *nfnlh; unsigned int addr_len; - struct nfnl_callback *cb; + int err; + + nfnlh = malloc(sizeof(*nfnlh)); + if (!nfnlh) + return NULL; - cb = malloc(sizeof(*cb) * cb_count); - if (!cb) - return -ENOMEM; - memset(nfnlh, 0, sizeof(*nfnlh)); nfnlh->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_NETFILTER); if (nfnlh->fd < 0) { nfnl_error("socket(netlink): %s", strerror(errno)); - return nfnlh->fd; + goto err_free; } nfnlh->local.nl_family = AF_NETLINK; - nfnlh->local.nl_groups = subscriptions; - nfnlh->peer.nl_family = AF_NETLINK; - err = bind(nfnlh->fd, (struct sockaddr *)&nfnlh->local, - sizeof(nfnlh->local)); - if (err < 0) { - nfnl_error("bind(netlink): %s", strerror(errno)); - return err; - } - addr_len = sizeof(nfnlh->local); err = getsockname(nfnlh->fd, (struct sockaddr *)&nfnlh->local, &addr_len); if (addr_len != sizeof(nfnlh->local)) { nfnl_error("Bad address length (%u != %zd)", addr_len, sizeof(nfnlh->local)); - return -1; + goto err_close; } if (nfnlh->local.nl_family != AF_NETLINK) { nfnl_error("Bad address family %d", nfnlh->local.nl_family); - return -1; + goto err_close; } nfnlh->seq = time(NULL); - nfnlh->subsys_id = subsys_id; - nfnlh->cb_count = cb_count; - nfnlh->cb = cb; - return 0; + return nfnlh; + +err_close: + close(nfnlh->fd); +err_free: + free(nfnlh); + return NULL; +} + +/** + * nfnl_subsys_open - open a netlink subsystem + * + * nfnlh: libnfnetlink handle + * subsys_id: which nfnetlink subsystem we are interested in + * cb_count: number of callbacks that are used maximum. + * subscriptions: netlink groups we want to be subscribed to + */ +struct nfnl_subsys_handle * +nfnl_subsys_open(struct nfnl_handle *nfnlh, u_int8_t subsys_id, + u_int8_t cb_count, u_int32_t subscriptions) +{ + struct nfnl_subsys_handle *ssh; + + if (subsys_id > NFNL_MAX_SUBSYS) { + + return NULL; + } + + ssh = &nfnlh->subsys[subsys_id]; + if (ssh->cb) { + + return NULL; + } + + ssh->cb = malloc(sizeof(*(ssh->cb)) * cb_count); + if (!ssh->cb) { + + return NULL; + } + + ssh->nfnlh = nfnlh; + ssh->cb_count = cb_count; + ssh->subscriptions = subscriptions; + + if (recalc_rebind_subscriptions(nfnlh) < 0) { + free(ssh->cb); + ssh->cb = NULL; + return NULL; + } + + return ssh; +} + +void nfnl_subsys_close(struct nfnl_subsys_handle *ssh) +{ + ssh->subscriptions = 0; + ssh->cb_count = 0; + if (ssh->cb) { + free(ssh->cb); + ssh->cb = NULL; + } } /** @@ -132,8 +224,18 @@ int nfnl_open(struct nfnl_handle *nfnlh, u_int8_t subsys_id, */ int nfnl_close(struct nfnl_handle *nfnlh) { - free(nfnlh->cb); - return close(nfnlh->fd); + int i, ret; + + for (i = 0; i < NFNL_MAX_SUBSYS; i++) + nfnl_subsys_close(&nfnlh->subsys[i]); + + ret = close(nfnlh->fd); + if (ret < 0) + return ret; + + free(nfnlh); + + return 0; } /** @@ -187,7 +289,7 @@ int nfnl_sendiov(const struct nfnl_handle *nfnlh, const struct iovec *iov, * the size of struct nlmsghdr + struct nfgenmsg * */ -void nfnl_fill_hdr(struct nfnl_handle *nfnlh, +void nfnl_fill_hdr(struct nfnl_subsys_handle *ssh, struct nlmsghdr *nlh, unsigned int len, u_int8_t family, u_int16_t res_id, @@ -198,10 +300,10 @@ void nfnl_fill_hdr(struct nfnl_handle *nfnlh, ((void *)nlh + sizeof(*nlh)); nlh->nlmsg_len = NLMSG_LENGTH(len+sizeof(*nfg)); - nlh->nlmsg_type = (nfnlh->subsys_id<<8)|msg_type; + nlh->nlmsg_type = (ssh->subsys_id<<8)|msg_type; nlh->nlmsg_flags = msg_flags; nlh->nlmsg_pid = 0; - nlh->nlmsg_seq = ++nfnlh->seq; + nlh->nlmsg_seq = ++ssh->nfnlh->seq; nfg->nfgen_family = family; nfg->version = NFNETLINK_V0; @@ -693,23 +795,23 @@ struct nlmsghdr *nfnl_get_msg_next(struct nfnl_handle *h, return nlh; } -int nfnl_callback_register(struct nfnl_handle *h, +int nfnl_callback_register(struct nfnl_subsys_handle *ssh, u_int8_t type, struct nfnl_callback *cb) { - if (type >= h->cb_count) + if (type >= ssh->cb_count) return -EINVAL; - memcpy(&h->cb[type], cb, sizeof(*cb)); + memcpy(&ssh->cb[type], cb, sizeof(*cb)); return 0; } -int nfnl_callback_unregister(struct nfnl_handle *h, u_int8_t type) +int nfnl_callback_unregister(struct nfnl_subsys_handle *ssh, u_int8_t type) { - if (type >= h->cb_count) + if (type >= ssh->cb_count) return -EINVAL; - h->cb[type].call = NULL; + ssh->cb[type].call = NULL; return 0; } @@ -720,12 +822,20 @@ int nfnl_check_attributes(const struct nfnl_handle *h, { int min_len; u_int8_t type = NFNL_MSG_TYPE(nlh->nlmsg_type); - struct nfnl_callback *cb = &h->cb[type]; + u_int8_t subsys_id = NFNL_SUBSYS_ID(nlh->nlmsg_type); + const struct nfnl_subsys_handle *ssh; + struct nfnl_callback *cb; + + if (subsys_id > NFNL_MAX_SUBSYS) + return -EINVAL; + + ssh = &h->subsys[subsys_id]; + cb = &ssh->cb[type]; #if 1 /* checks need to be enabled as soon as this is called from * somebody else than __nfnl_handle_msg */ - if (type >= h->cb_count) + if (type >= ssh->cb_count) return -EINVAL; min_len = NLMSG_ALIGN(sizeof(struct nfgenmsg)); @@ -755,26 +865,30 @@ int nfnl_check_attributes(const struct nfnl_handle *h, static int __nfnl_handle_msg(struct nfnl_handle *h, struct nlmsghdr *nlh, int len) { + struct nfnl_subsys_handle *ssh; u_int8_t type = NFNL_MSG_TYPE(nlh->nlmsg_type); + u_int8_t subsys_id = NFNL_SUBSYS_ID(nlh->nlmsg_type); int err = 0; - if (NFNL_SUBSYS_ID(nlh->nlmsg_type) != h->subsys_id) + if (subsys_id > NFNL_MAX_SUBSYS) return -1; + ssh = &h->subsys[subsys_id]; + if (nlh->nlmsg_len < NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct nfgenmsg)))) return -1; - if (type >= h->cb_count) + if (type >= ssh->cb_count) return -1; - if (h->cb[type].attr_count) { - struct nfattr *nfa[h->cb[type].attr_count]; + if (ssh->cb[type].attr_count) { + struct nfattr *nfa[ssh->cb[type].attr_count]; err = nfnl_check_attributes(h, nlh, nfa); if (err < 0) return err; - if (h->cb[type].call) - return h->cb[type].call(nlh, nfa, h->cb[type].data); + if (ssh->cb[type].call) + return ssh->cb[type].call(nlh, nfa, ssh->cb[type].data); } return 0; } |