From aa38b2ffd4d4d738a7ebb6981afc778174d56753 Mon Sep 17 00:00:00 2001 From: Fabian Hugelshofer Date: Wed, 18 Jun 2008 15:12:14 +0200 Subject: Use union to ensure proper alignment This patch increases portability, but alignment is still not respected in nflog_get_*() which still leaves libnetfilter_log unusable on particular platforms. Signed-off-by: Fabian Hugelshofer --- src/libnetfilter_log.c | 76 +++++++++++++++++++++++++++++--------------------- 1 file changed, 44 insertions(+), 32 deletions(-) diff --git a/src/libnetfilter_log.c b/src/libnetfilter_log.c index a3bd435..2019b0c 100644 --- a/src/libnetfilter_log.c +++ b/src/libnetfilter_log.c @@ -106,18 +106,20 @@ static int __build_send_cfg_msg(struct nflog_handle *h, u_int8_t command, u_int16_t queuenum, u_int8_t pf) { - char buf[NFNL_HEADER_LEN - +NFA_LENGTH(sizeof(struct nfulnl_msg_config_cmd))]; + union { + char buf[NFNL_HEADER_LEN + +NFA_LENGTH(sizeof(struct nfulnl_msg_config_cmd))]; + struct nlmsghdr nmh; + } u; struct nfulnl_msg_config_cmd cmd; - struct nlmsghdr *nmh = (struct nlmsghdr *) buf; - nfnl_fill_hdr(h->nfnlssh, nmh, 0, pf, queuenum, + nfnl_fill_hdr(h->nfnlssh, &u.nmh, 0, pf, queuenum, NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK); cmd.command = command; - nfnl_addattr_l(nmh, sizeof(buf), NFULA_CFG_CMD, &cmd, sizeof(cmd)); + nfnl_addattr_l(&u.nmh, sizeof(u), NFULA_CFG_CMD, &cmd, sizeof(cmd)); - return nfnl_talk(h->nfnlh, nmh, 0, 0, NULL, NULL, NULL); + return nfnl_talk(h->nfnlh, &u.nmh, 0, 0, NULL, NULL, NULL); } static int __nflog_rcv_pkt(struct nlmsghdr *nlh, struct nfattr *nfa[], @@ -291,60 +293,68 @@ int nflog_unbind_group(struct nflog_g_handle *gh) int nflog_set_mode(struct nflog_g_handle *gh, u_int8_t mode, u_int32_t range) { - char buf[NFNL_HEADER_LEN - +NFA_LENGTH(sizeof(struct nfulnl_msg_config_mode))]; + union { + char buf[NFNL_HEADER_LEN + +NFA_LENGTH(sizeof(struct nfulnl_msg_config_mode))]; + struct nlmsghdr nmh; + } u; struct nfulnl_msg_config_mode params; - struct nlmsghdr *nmh = (struct nlmsghdr *) buf; - nfnl_fill_hdr(gh->h->nfnlssh, nmh, 0, AF_UNSPEC, gh->id, + nfnl_fill_hdr(gh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, gh->id, NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK); params.copy_range = htonl(range); /* copy_range is short */ params.copy_mode = mode; - nfnl_addattr_l(nmh, sizeof(buf), NFULA_CFG_MODE, ¶ms, + nfnl_addattr_l(&u.nmh, sizeof(u), NFULA_CFG_MODE, ¶ms, sizeof(params)); - return nfnl_talk(gh->h->nfnlh, nmh, 0, 0, NULL, NULL, NULL); + return nfnl_talk(gh->h->nfnlh, &u.nmh, 0, 0, NULL, NULL, NULL); } int nflog_set_timeout(struct nflog_g_handle *gh, u_int32_t timeout) { - char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(u_int32_t))]; - struct nlmsghdr *nmh = (struct nlmsghdr *) buf; + union { + char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(u_int32_t))]; + struct nlmsghdr nmh; + } u; - nfnl_fill_hdr(gh->h->nfnlssh, nmh, 0, AF_UNSPEC, gh->id, + nfnl_fill_hdr(gh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, gh->id, NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK); - nfnl_addattr32(nmh, sizeof(buf), NFULA_CFG_TIMEOUT, htonl(timeout)); + nfnl_addattr32(&u.nmh, sizeof(u), NFULA_CFG_TIMEOUT, htonl(timeout)); - return nfnl_talk(gh->h->nfnlh, nmh, 0, 0, NULL, NULL, NULL); + return nfnl_talk(gh->h->nfnlh, &u.nmh, 0, 0, NULL, NULL, NULL); } int nflog_set_qthresh(struct nflog_g_handle *gh, u_int32_t qthresh) { - char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(u_int32_t))]; - struct nlmsghdr *nmh = (struct nlmsghdr *) buf; + union { + char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(u_int32_t))]; + struct nlmsghdr nmh; + } u; - nfnl_fill_hdr(gh->h->nfnlssh, nmh, 0, AF_UNSPEC, gh->id, + nfnl_fill_hdr(gh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, gh->id, NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK); - nfnl_addattr32(nmh, sizeof(buf), NFULA_CFG_QTHRESH, htonl(qthresh)); + nfnl_addattr32(&u.nmh, sizeof(u), NFULA_CFG_QTHRESH, htonl(qthresh)); - return nfnl_talk(gh->h->nfnlh, nmh, 0, 0, NULL, NULL, NULL); + return nfnl_talk(gh->h->nfnlh, &u.nmh, 0, 0, NULL, NULL, NULL); } int nflog_set_nlbufsiz(struct nflog_g_handle *gh, u_int32_t nlbufsiz) { - char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(u_int32_t))]; - struct nlmsghdr *nmh = (struct nlmsghdr *) buf; + union { + char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(u_int32_t))]; + struct nlmsghdr nmh; + } u; int status; - nfnl_fill_hdr(gh->h->nfnlssh, nmh, 0, AF_UNSPEC, gh->id, + nfnl_fill_hdr(gh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, gh->id, NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK); - nfnl_addattr32(nmh, sizeof(buf), NFULA_CFG_NLBUFSIZ, htonl(nlbufsiz)); + nfnl_addattr32(&u.nmh, sizeof(u), NFULA_CFG_NLBUFSIZ, htonl(nlbufsiz)); - status = nfnl_talk(gh->h->nfnlh, nmh, 0, 0, NULL, NULL, NULL); + status = nfnl_talk(gh->h->nfnlh, &u.nmh, 0, 0, NULL, NULL, NULL); /* we try to have space for at least 10 messages in the socket buffer */ if (status >= 0) @@ -355,15 +365,17 @@ int nflog_set_nlbufsiz(struct nflog_g_handle *gh, u_int32_t nlbufsiz) int nflog_set_flags(struct nflog_g_handle *gh, u_int16_t flags) { - char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(u_int16_t))]; - struct nlmsghdr *nmh = (struct nlmsghdr *) buf; + union { + char buf[NFNL_HEADER_LEN+NFA_LENGTH(sizeof(u_int16_t))]; + struct nlmsghdr nmh; + } u; - nfnl_fill_hdr(gh->h->nfnlssh, nmh, 0, AF_UNSPEC, gh->id, + nfnl_fill_hdr(gh->h->nfnlssh, &u.nmh, 0, AF_UNSPEC, gh->id, NFULNL_MSG_CONFIG, NLM_F_REQUEST|NLM_F_ACK); - nfnl_addattr16(nmh, sizeof(buf), NFULA_CFG_FLAGS, htons(flags)); + nfnl_addattr16(&u.nmh, sizeof(u), NFULA_CFG_FLAGS, htons(flags)); - return nfnl_talk(gh->h->nfnlh, nmh, 0, 0, NULL, NULL, NULL); + return nfnl_talk(gh->h->nfnlh, &u.nmh, 0, 0, NULL, NULL, NULL); } -- cgit v1.2.3