From ccc95c1e13927a081690e0b3dde7441a86c6f266 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Tue, 3 Jun 2014 23:21:50 +0200 Subject: [PATCH] dns: use common function for sending packets Signed-off-by: Felix Fietkau --- dns.c | 75 ++++++++++++++++++++++++++++++++----------------------------------- 1 file changed, 36 insertions(+), 39 deletions(-) diff --git a/dns.c b/dns.c index 5595384..517825b 100644 --- a/dns.c +++ b/dns.c @@ -65,10 +65,43 @@ dns_type_string(uint16_t type) return "N/A"; } +static int +dns_send_packet(int fd, struct iovec *iov, int iov_len) +{ + static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1]; + static struct sockaddr_in a = { + .sin_family = AF_INET, + .sin_port = htons(MCAST_PORT), + }; + static struct msghdr m = { + .msg_name = (struct sockaddr *) &a, + .msg_namelen = sizeof(a), + .msg_control = cmsg_data, + .msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)), + }; + struct in_pktinfo *pkti; + struct cmsghdr *cmsg; + + m.msg_iov = iov; + m.msg_iovlen = iov_len; + + memset(cmsg_data, 0, sizeof(cmsg_data)); + cmsg = CMSG_FIRSTHDR(&m); + cmsg->cmsg_len = m.msg_controllen; + cmsg->cmsg_level = IPPROTO_IP; + cmsg->cmsg_type = IP_PKTINFO; + + pkti = (struct in_pktinfo*) CMSG_DATA(cmsg); + pkti->ipi_ifindex = iface_index; + + a.sin_addr.s_addr = inet_addr(MCAST_ADDR); + + return sendmsg(fd, &m, 0); +} + void dns_send_question(struct uloop_fd *u, char *question, int type) { - static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1]; static struct dns_header h = { .questions = cpu_to_be16(1), }; @@ -88,23 +121,8 @@ dns_send_question(struct uloop_fd *u, char *question, int type) .iov_len = sizeof(q), } }; - static struct sockaddr_in a = { - .sin_family = AF_INET, - .sin_port = htons(MCAST_PORT), - }; - static struct msghdr m = { - .msg_name = (struct sockaddr *) &a, - .msg_namelen = sizeof(a), - .msg_iov = iov, - .msg_iovlen = ARRAY_SIZE(iov), - .msg_control = cmsg_data, - .msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)), - }; - struct in_pktinfo *pkti; - struct cmsghdr *cmsg; int len; - a.sin_addr.s_addr = inet_addr(MCAST_ADDR); q.type = __cpu_to_be16(type); len = dn_comp(question, (void *) name_buffer, sizeof(name_buffer), NULL, NULL); @@ -113,17 +131,7 @@ dns_send_question(struct uloop_fd *u, char *question, int type) iov[1].iov_len = len; - memset(cmsg_data, 0, sizeof(cmsg_data)); - - cmsg = CMSG_FIRSTHDR(&m); - cmsg->cmsg_len = m.msg_controllen; - cmsg->cmsg_level = IPPROTO_IP; - cmsg->cmsg_type = IP_PKTINFO; - - pkti = (struct in_pktinfo*) CMSG_DATA(cmsg); - pkti->ipi_ifindex = iface_index; - - if (sendmsg(u->fd, &m, 0) < 0) + if (dns_send_packet(u->fd, iov, ARRAY_SIZE(iov)) < 0) fprintf(stderr, "failed to send question\n"); else DBG(1, "Q <- %s %s\n", dns_type_string(type), question); @@ -165,18 +173,12 @@ dns_send_answer(struct uloop_fd *u, char *answer) { uint8_t buffer[256]; struct dns_header h = { 0 }; - struct msghdr m = { 0 }; struct iovec *iov; - struct sockaddr_in in = { 0 }; int len, i; if (!dns_answer_cnt) return; - in.sin_family = AF_INET; - in.sin_addr.s_addr = inet_addr(MCAST_ADDR); - in.sin_port = htons(MCAST_PORT); - h.answers = __cpu_to_be16(dns_answer_cnt); h.flags = __cpu_to_be16(0x8400); @@ -184,11 +186,6 @@ dns_send_answer(struct uloop_fd *u, char *answer) if (!iov) return; - m.msg_name = ∈ - m.msg_namelen = sizeof(struct sockaddr_in); - m.msg_iov = iov; - m.msg_iovlen = (dns_answer_cnt * 3) + 1; - iov[0].iov_base = &h; iov[0].iov_len = sizeof(struct dns_header); @@ -218,7 +215,7 @@ dns_send_answer(struct uloop_fd *u, char *answer) DBG(1, "A <- %s %s\n", dns_type_string(dns_reply[i].type), answer); } - if (sendmsg(u->fd, &m, 0) < 0) + if (dns_send_packet(u->fd, iov, (dns_answer_cnt * 3) + 1) < 0) fprintf(stderr, "failed to send question\n"); for (i = 0; i < dns_answer_cnt; i++) { -- 2.11.0