add infrastrtcur for creating and sending DNS packets

git-svn-id: file:///home/lennart/svn/public/avahi/trunk@10 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

1 files changed, 415 insertions, 0 deletions

diff --git a/socket.c b/socket.c
new file mode 100644
index 0000000..a77f631
--- /dev/null
+++ b/socket.c
@@ -0,0 +1,415 @@
+#include <inttypes.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/time.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+
+#include "dns.h"
+#include "util.h"
+
+#define MDNS_PORT 5353
+
+static void mdns_mcast_group_ipv4(struct sockaddr_in *ret_sa) {
+    g_assert(ret_sa);
+
+    memset(ret_sa, 0, sizeof(struct sockaddr_in));
+    
+    ret_sa->sin_family = AF_INET;
+    ret_sa->sin_port = htons(MDNS_PORT);
+    inet_pton(AF_INET, "224.0.0.251", &ret_sa->sin_addr);
+}
+
+gint flx_open_socket_ipv4(void) {
+    struct ip_mreqn mreq;
+    struct sockaddr_in sa, local;
+    int fd = -1, ttl, yes;
+
+    mdns_mcast_group_ipv4(&sa);
+        
+    if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
+        g_warning("socket() failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    ttl = 255;
+    if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) {
+        g_warning("IP_MULTICAST_TTL failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    ttl = 255;
+    if (setsockopt(fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) < 0) {
+        g_warning("IP_TTL failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    yes = 1;
+    if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
+        g_warning("SO_REUSEADDR failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    memset(&local, 0, sizeof(local));
+    local.sin_family = AF_INET;
+    local.sin_port = htons(MDNS_PORT);
+    
+    if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
+        g_warning("bind() failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    memset(&mreq, 0, sizeof(mreq));
+    mreq.imr_multiaddr = sa.sin_addr;
+    mreq.imr_address.s_addr = htonl(INADDR_ANY);
+    mreq.imr_ifindex = 0;
+    
+    if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+        g_warning("IP_ADD_MEMBERSHIP failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IP, IP_RECVTTL, &yes, sizeof(yes)) < 0) {
+        g_warning("IP_RECVTTL failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &yes, sizeof(yes)) < 0) {
+        g_warning("IP_PKTINFO failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    if (flx_set_cloexec(fd) < 0) {
+        g_warning("FD_CLOEXEC failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    if (flx_set_nonblock(fd) < 0) {
+        g_warning("O_NONBLOCK failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    return fd;
+
+fail:
+    if (fd >= 0)
+        close(fd);
+
+    return -1;
+}
+
+static void mdns_mcast_group_ipv6(struct sockaddr_in6 *ret_sa) {
+    g_assert(ret_sa);
+
+    memset(ret_sa, 0, sizeof(struct sockaddr_in6));
+    
+    ret_sa->sin6_family = AF_INET6;
+    ret_sa->sin6_port = htons(MDNS_PORT);
+    inet_pton(AF_INET6, "ff02::fb", &ret_sa->sin6_addr);
+}
+
+
+gint flx_open_socket_ipv6(void) {
+    struct ipv6_mreq mreq;
+    struct sockaddr_in6 sa, local;
+    int fd = -1, ttl, yes;
+
+    mdns_mcast_group_ipv6(&sa);
+        
+    if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
+        g_warning("socket() failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    ttl = 255;
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
+        g_warning("IPV6_MULTICAST_HOPS failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    ttl = 255;
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl)) < 0) {
+        g_warning("IPV6_UNICAST_HOPS failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    yes = 1;
+    if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0) {
+        g_warning("SO_REUSEADDR failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    memset(&local, 0, sizeof(local));
+    local.sin6_family = AF_INET6;
+    local.sin6_port = htons(MDNS_PORT);
+    
+    if (bind(fd, (struct sockaddr*) &local, sizeof(local)) < 0) {
+        g_warning("bind() failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    memset(&mreq, 0, sizeof(mreq));
+    mreq.ipv6mr_multiaddr = sa.sin6_addr;
+    mreq.ipv6mr_interface = 0;
+    
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
+        g_warning("IPV6_ADD_MEMBERSHIP failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_HOPLIMIT, &yes, sizeof(yes)) < 0) {
+        g_warning("IPV6_HOPLIMIT failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    yes = 1;
+    if (setsockopt(fd, IPPROTO_IPV6, IPV6_PKTINFO, &yes, sizeof(yes)) < 0) {
+        g_warning("IPV6_PKTINFO failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    if (flx_set_cloexec(fd) < 0) {
+        g_warning("FD_CLOEXEC failed: %s\n", strerror(errno));
+        goto fail;
+    }
+    
+    if (flx_set_nonblock(fd) < 0) {
+        g_warning("O_NONBLOCK failed: %s\n", strerror(errno));
+        goto fail;
+    }
+
+    return fd;
+
+fail:
+    if (fd >= 0)
+        close(fd);
+
+    return -1;
+}
+
+static gint sendmsg_loop(gint fd, struct msghdr *msg, gint flags) {
+    g_assert(fd >= 0);
+    g_assert(msg);
+
+    for (;;) {
+    
+        if (sendmsg(fd, msg, flags) >= 0)
+            break;
+        
+        if (errno != EAGAIN) {
+            g_message("sendmsg() failed: %s\n", strerror(errno));
+            return -1;
+        }
+        
+        if (flx_wait_for_write(fd) < 0)
+            return -1;
+    }
+
+    return 0;
+}
+
+gint flx_send_dns_packet_ipv4(gint fd, gint interface, flxDnsPacket *p) {
+    struct sockaddr_in sa;
+    struct msghdr msg;
+    struct iovec io;
+    struct cmsghdr *cmsg;
+    struct in_pktinfo *pkti;
+    uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in_pktinfo)];
+    int i, n;
+
+    g_assert(fd >= 0);
+    g_assert(p);
+    g_assert(flx_dns_packet_check_valid(p) >= 0);
+
+    mdns_mcast_group_ipv4(&sa);
+
+    memset(&io, 0, sizeof(io));
+    io.iov_base = p->data;
+    io.iov_len = p->size;
+
+    memset(cmsg_data, 0, sizeof(cmsg_data));
+    cmsg = (struct cmsghdr*) cmsg_data;
+    cmsg->cmsg_len = sizeof(cmsg_data);
+    cmsg->cmsg_level = IPPROTO_IP;
+    cmsg->cmsg_type = IP_PKTINFO;
+
+    pkti = (struct in_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
+    pkti->ipi_ifindex = interface;
+    
+    memset(&msg, 0, sizeof(msg));
+    msg.msg_name = &sa;
+    msg.msg_namelen = sizeof(sa);
+    msg.msg_iov = &io;
+    msg.msg_iovlen = 1;
+    msg.msg_control = cmsg_data;
+    msg.msg_controllen = sizeof(cmsg_data);
+    msg.msg_flags = 0;
+
+    return sendmsg_loop(fd, &msg, MSG_DONTROUTE);
+}
+
+gint flx_send_dns_packet_ipv6(gint fd, gint interface, flxDnsPacket *p) {
+    struct sockaddr_in6 sa;
+    struct msghdr msg;
+    struct iovec io;
+    struct cmsghdr *cmsg;
+    struct in6_pktinfo *pkti;
+    uint8_t cmsg_data[sizeof(struct cmsghdr) + sizeof(struct in6_pktinfo)];
+    int i, n;
+
+    g_assert(fd >= 0);
+    g_assert(p);
+    g_assert(flx_dns_packet_check_valid(p) >= 0);
+
+    mdns_mcast_group_ipv6(&sa);
+
+    memset(&io, 0, sizeof(io));
+    io.iov_base = p->data;
+    io.iov_len = p->size;
+
+    memset(cmsg_data, 0, sizeof(cmsg_data));
+    cmsg = (struct cmsghdr*) cmsg_data;
+    cmsg->cmsg_len = sizeof(cmsg_data);
+    cmsg->cmsg_level = IPPROTO_IPV6;
+    cmsg->cmsg_type = IPV6_PKTINFO;
+
+    pkti = (struct in6_pktinfo*) (cmsg_data + sizeof(struct cmsghdr));
+    pkti->ipi6_ifindex = interface;
+    
+    memset(&msg, 0, sizeof(msg));
+    msg.msg_name = &sa;
+    msg.msg_namelen = sizeof(sa);
+    msg.msg_iov = &io;
+    msg.msg_iovlen = 1;
+    msg.msg_control = cmsg_data;
+    msg.msg_controllen = sizeof(cmsg_data);
+    msg.msg_flags = 0;
+
+    return sendmsg_loop(fd, &msg, MSG_DONTROUTE);
+}
+
+flxDnsPacket* flx_recv_dns_packet_ipv4(gint fd, struct sockaddr_in *ret_sa, gint *ret_iface, guint8* ret_ttl) {
+    flxDnsPacket *p= NULL;
+    struct msghdr msg;
+    struct iovec io;
+    uint8_t aux[64];
+    ssize_t l;
+    struct cmsghdr *cmsg;
+    gboolean found_ttl = FALSE, found_iface = FALSE;
+
+    g_assert(fd >= 0);
+    g_assert(ret_sa);
+    g_assert(ret_iface);
+    g_assert(ret_ttl);
+
+    p = flx_dns_packet_new();
+
+    io.iov_base = p->data;
+    io.iov_len = sizeof(p->data);
+    
+    memset(&msg, 0, sizeof(msg));
+    msg.msg_name = ret_sa;
+    msg.msg_namelen = sizeof(struct sockaddr_in);
+    msg.msg_iov = &io;
+    msg.msg_iovlen = 1;
+    msg.msg_control = aux;
+    msg.msg_controllen = sizeof(aux);
+    msg.msg_flags = 0;
+    
+    if ((l = recvmsg(fd, &msg, 0)) < 0)
+        goto fail;
+
+    p->size = (size_t) l;
+    
+    *ret_ttl = 0;
+        
+    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg,cmsg)) {
+        if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_TTL) {
+            *ret_ttl = *(uint8_t *) CMSG_DATA(cmsg);
+            found_ttl = TRUE;
+        }
+            
+        if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_PKTINFO) {
+            *ret_iface = ((struct in_pktinfo*) CMSG_DATA(cmsg))->ipi_ifindex;
+            found_iface = TRUE;
+        }
+    }
+
+    g_assert(found_iface && found_ttl);
+
+    return p;
+
+fail:
+    if (p)
+        flx_dns_packet_free(p);
+
+    return NULL;
+}
+
+flxDnsPacket* flx_recv_dns_packet_ipv6(gint fd, struct sockaddr_in6 *ret_sa, gint *ret_iface, guint8* ret_ttl) {
+    flxDnsPacket *p= NULL;
+    struct msghdr msg;
+    struct iovec io;
+    uint8_t aux[64];
+    ssize_t l;
+    struct cmsghdr *cmsg;
+    gboolean found_ttl = FALSE, found_iface = FALSE;
+
+    g_assert(fd >= 0);
+    g_assert(ret_sa);
+    g_assert(ret_iface);
+    g_assert(ret_ttl);
+
+    p = flx_dns_packet_new();
+
+    io.iov_base = p->data;
+    io.iov_len = sizeof(p->data);
+    
+    memset(&msg, 0, sizeof(msg));
+    msg.msg_name = ret_sa;
+    msg.msg_namelen = sizeof(struct sockaddr_in6);
+    msg.msg_iov = &io;
+    msg.msg_iovlen = 1;
+    msg.msg_control = aux;
+    msg.msg_controllen = sizeof(aux);
+    msg.msg_flags = 0;
+    
+    if ((l = recvmsg(fd, &msg, 0)) < 0)
+        goto fail;
+
+    p->size = (size_t) l;
+    
+    *ret_ttl = 0;
+        
+    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg,cmsg)) {
+        if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IPV6_HOPLIMIT) {
+            *ret_ttl = *(uint8_t *) CMSG_DATA(cmsg);
+            found_ttl = TRUE;
+        }
+            
+        if (cmsg->cmsg_level == IPPROTO_IP && cmsg->cmsg_type == IPV6_PKTINFO) {
+            *ret_iface = ((struct in_pktinfo*) CMSG_DATA(cmsg))->ipi_ifindex;
+            found_iface = TRUE;
+        }
+    }
+
+    g_assert(found_iface && found_ttl);
+
+    return p;
+
+fail:
+    if (p)
+        flx_dns_packet_free(p);
+
+    return NULL;
+}
+