/* * BIRD Internet Routing Daemon -- Linux Multicasting and Network Includes * * (c) 1998--2000 Martin Mares <mj@ucw.cz> * * Can be freely distributed and used under the terms of the GNU GPL. */ #include <net/if.h> #ifdef IPV6 #ifndef IPV6_UNICAST_HOPS /* Needed on glibc 2.0 systems */ #include <linux/in6.h> #define CONFIG_IPV6_GLIBC_20 #endif static inline void set_inaddr(struct in6_addr *ia, ip_addr a) { ipa_hton(a); memcpy(ia, &a, sizeof(a)); } static inline void get_inaddr(ip_addr *a, struct in6_addr *ia) { memcpy(a, ia, sizeof(*a)); ipa_ntoh(*a); } static inline char * sysio_bind_to_iface(sock *s) { struct ifreq ifr; strcpy(ifr.ifr_name, s->iface->name); if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0) return "SO_BINDTODEVICE"; return NULL; } #else static inline void set_inaddr(struct in_addr *ia, ip_addr a) { ipa_hton(a); memcpy(&ia->s_addr, &a, sizeof(a)); } static inline void get_inaddr(ip_addr *a, struct in_addr *ia) { memcpy(a, &ia->s_addr, sizeof(*a)); ipa_ntoh(*a); } /* * Multicasting in Linux systems is a real mess. Not only different kernels * have different interfaces, but also different libc's export it in different * ways. Horrible. */ #if defined(CONFIG_LINUX_MC_MREQ) || defined(CONFIG_LINUX_MC_MREQ_BIND) /* * Older kernels support only struct mreq which matches interfaces by their * addresses and thus fails on unnumbered devices. On newer 2.0 kernels * we can use SO_BINDTODEVICE to circumvent this problem. */ #define MREQ_IFA struct in_addr #define MREQ_GRP struct ip_mreq static inline void fill_mreq_ifa(struct in_addr *m, struct iface *ifa UNUSED, ip_addr saddr, ip_addr maddr UNUSED) { set_inaddr(m, saddr); } static inline void fill_mreq_grp(struct ip_mreq *m, struct iface *ifa, ip_addr saddr, ip_addr maddr) { bzero(m, sizeof(*m)); #ifdef CONFIG_LINUX_MC_MREQ_BIND m->imr_interface.s_addr = INADDR_ANY; #else set_inaddr(&m->imr_interface, saddr); #endif set_inaddr(&m->imr_multiaddr, maddr); } #endif #ifdef CONFIG_LINUX_MC_MREQN /* * 2.1 and newer kernels use struct mreqn which passes ifindex, so no * problems with unnumbered devices. */ #ifndef HAVE_STRUCT_IP_MREQN /* Several versions of glibc don't define this structure, so we have to do it ourselves */ struct ip_mreqn { struct in_addr imr_multiaddr; /* IP multicast address of group */ struct in_addr imr_address; /* local IP address of interface */ int imr_ifindex; /* Interface index */ }; #endif #define MREQ_IFA struct ip_mreqn #define MREQ_GRP struct ip_mreqn #define fill_mreq_ifa fill_mreq #define fill_mreq_grp fill_mreq static inline void fill_mreq(struct ip_mreqn *m, struct iface *ifa, ip_addr saddr, ip_addr maddr) { bzero(m, sizeof(*m)); m->imr_ifindex = ifa->index; set_inaddr(&m->imr_address, saddr); set_inaddr(&m->imr_multiaddr, maddr); } #endif static inline char * sysio_setup_multicast(sock *s) { MREQ_IFA m; int zero = 0; if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_LOOP, &zero, sizeof(zero)) < 0) return "IP_MULTICAST_LOOP"; if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_TTL, &s->ttl, sizeof(s->ttl)) < 0) return "IP_MULTICAST_TTL"; /* This defines where should we send _outgoing_ multicasts */ fill_mreq_ifa(&m, s->iface, s->saddr, IPA_NONE); if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_IF, &m, sizeof(m)) < 0) return "IP_MULTICAST_IF"; #if defined(CONFIG_LINUX_MC_MREQ_BIND) || defined(CONFIG_LINUX_MC_MREQN) { struct ifreq ifr; strcpy(ifr.ifr_name, s->iface->name); if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0) return "SO_BINDTODEVICE"; } #endif return NULL; } static inline char * sysio_join_group(sock *s, ip_addr maddr) { MREQ_GRP m; /* And this one sets interface for _receiving_ multicasts from */ fill_mreq_grp(&m, s->iface, s->saddr, maddr); if (setsockopt(s->fd, SOL_IP, IP_ADD_MEMBERSHIP, &m, sizeof(m)) < 0) return "IP_ADD_MEMBERSHIP"; return NULL; } static inline char * sysio_leave_group(sock *s, ip_addr maddr) { MREQ_GRP m; /* And this one sets interface for _receiving_ multicasts from */ fill_mreq_grp(&m, s->iface, s->saddr, maddr); if (setsockopt(s->fd, SOL_IP, IP_DROP_MEMBERSHIP, &m, sizeof(m)) < 0) return "IP_DROP_MEMBERSHIP"; return NULL; } #endif #include <linux/socket.h> #include <linux/tcp.h> /* For the case that we have older kernel headers */ /* Copied from Linux kernel file include/linux/tcp.h */ #ifndef TCP_MD5SIG #define TCP_MD5SIG 14 #define TCP_MD5SIG_MAXKEYLEN 80 struct tcp_md5sig { struct sockaddr_storage tcpm_addr; /* address associated */ __u16 __tcpm_pad1; /* zero */ __u16 tcpm_keylen; /* key length */ __u32 __tcpm_pad2; /* zero */ __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */ }; #endif static int sk_set_md5_auth_int(sock *s, sockaddr *sa, char *passwd) { struct tcp_md5sig md5; memset(&md5, 0, sizeof(md5)); memcpy(&md5.tcpm_addr, (struct sockaddr *) sa, sizeof(*sa)); if (passwd) { int len = strlen(passwd); if (len > TCP_MD5SIG_MAXKEYLEN) { log(L_ERR "MD5 password too long"); return -1; } md5.tcpm_keylen = len; memcpy(&md5.tcpm_key, passwd, len); } int rv = setsockopt(s->fd, IPPROTO_TCP, TCP_MD5SIG, &md5, sizeof(md5)); if (rv < 0) { if (errno == ENOPROTOOPT) log(L_ERR "Kernel does not support TCP MD5 signatures"); else log(L_ERR "sk_set_md5_auth_int: setsockopt: %m"); } return rv; } #ifndef IPV6 /* RX/TX packet info handling for IPv4 */ /* Mostly similar to standardized IPv6 code */ #define CMSG_RX_SPACE CMSG_SPACE(sizeof(struct in_pktinfo)) #define CMSG_TX_SPACE CMSG_SPACE(sizeof(struct in_pktinfo)) static char * sysio_register_cmsgs(sock *s) { int ok = 1; if ((s->flags & SKF_LADDR_RX) && setsockopt(s->fd, IPPROTO_IP, IP_PKTINFO, &ok, sizeof(ok)) < 0) return "IP_PKTINFO"; return NULL; } static void sysio_process_rx_cmsgs(sock *s, struct msghdr *msg) { struct cmsghdr *cm; struct in_pktinfo *pi = NULL; if (!(s->flags & SKF_LADDR_RX)) return; for (cm = CMSG_FIRSTHDR(msg); cm != NULL; cm = CMSG_NXTHDR(msg, cm)) { if (cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_PKTINFO) pi = (struct in_pktinfo *) CMSG_DATA(cm); } if (!pi) { s->laddr = IPA_NONE; s->lifindex = 0; return; } get_inaddr(&s->laddr, &pi->ipi_addr); s->lifindex = pi->ipi_ifindex; return; } static void sysio_prepare_tx_cmsgs(sock *s, struct msghdr *msg, void *cbuf, size_t cbuflen) { struct cmsghdr *cm; struct in_pktinfo *pi; if (!(s->flags & SKF_LADDR_TX)) return; msg->msg_control = cbuf; msg->msg_controllen = cbuflen; cm = CMSG_FIRSTHDR(msg); cm->cmsg_level = IPPROTO_IP; cm->cmsg_type = IP_PKTINFO; cm->cmsg_len = CMSG_LEN(sizeof(*pi)); pi = (struct in_pktinfo *) CMSG_DATA(cm); set_inaddr(&pi->ipi_spec_dst, s->saddr); pi->ipi_ifindex = s->iface ? s->iface->index : 0; msg->msg_controllen = cm->cmsg_len; } #endif