X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Flibsystemd-network%2Fdhcp-network.c;h=5f2d2cfbfd1d1482db6a1103dd3671c4f0dd6fd3;hp=a9a15b4d5adc156b6ef5c17671d7df5eca2f54ee;hb=e2acdb6b0f68d9b4152708a9f21bf9e11f8b9e7e;hpb=0c79c68d93d721d37ba088fb50dbf07bb0d447e5 diff --git a/src/libsystemd-network/dhcp-network.c b/src/libsystemd-network/dhcp-network.c index a9a15b4d5..5f2d2cfbf 100644 --- a/src/libsystemd-network/dhcp-network.c +++ b/src/libsystemd-network/dhcp-network.c @@ -22,7 +22,9 @@ #include #include #include +#include #include +#include #include #include #include @@ -31,98 +33,204 @@ #include "dhcp-internal.h" -int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link) -{ +static int _bind_raw_socket(int ifindex, union sockaddr_union *link, + uint32_t xid, const uint8_t *mac_addr, + size_t mac_addr_len, + const uint8_t *bcast_addr, + const struct ether_addr *eth_mac, + uint16_t arp_type, uint8_t dhcp_hlen) { struct sock_filter filter[] = { - BPF_STMT(BPF_LD + BPF_W + BPF_LEN, 0), /* A <- packet length */ - BPF_JUMP(BPF_JMP + BPF_JGE + BPF_K, sizeof(DHCPPacket), 1, 0), /* packet >= DHCPPacket ? */ - BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ - BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, ip.protocol)), /* A <- IP protocol */ - BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 1, 0), /* IP protocol == UDP ? */ - BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ - BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, udp.dest)), /* A <- UDP destination port */ - BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DHCP_PORT_CLIENT, 1, 0), /* UDP destination port == DHCP client port ? */ - BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ - BPF_STMT(BPF_RET + BPF_K, 65535), /* return all */ + BPF_STMT(BPF_LD + BPF_W + BPF_LEN, 0), /* A <- packet length */ + BPF_JUMP(BPF_JMP + BPF_JGE + BPF_K, sizeof(DHCPPacket), 1, 0), /* packet >= DHCPPacket ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, ip.protocol)), /* A <- IP protocol */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 1, 0), /* IP protocol == UDP ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, ip.frag_off)), /* A <- Flags */ + BPF_STMT(BPF_ALU + BPF_AND + BPF_K, 0x20), /* A <- A & 0x20 (More Fragments bit) */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, ip.frag_off)), /* A <- Flags + Fragment offset */ + BPF_STMT(BPF_ALU + BPF_AND + BPF_K, 0x1fff), /* A <- A & 0x1fff (Fragment offset) */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, udp.dest)), /* A <- UDP destination port */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DHCP_PORT_CLIENT, 1, 0), /* UDP destination port == DHCP client port ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.op)), /* A <- DHCP op */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, BOOTREPLY, 1, 0), /* op == BOOTREPLY ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.htype)), /* A <- DHCP header type */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, arp_type, 1, 0), /* header type == arp_type ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_B + BPF_ABS, offsetof(DHCPPacket, dhcp.hlen)), /* A <- MAC address length */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, dhcp_hlen, 1, 0), /* address length == dhcp_hlen ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.xid)), /* A <- client identifier */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, xid, 1, 0), /* client identifier == xid ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_IMM, htobe32(*((unsigned int *) eth_mac))), /* A <- 4 bytes of client's MAC */ + BPF_STMT(BPF_MISC + BPF_TAX, 0), /* X <- A */ + BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.chaddr)), /* A <- 4 bytes of MAC from dhcp.chaddr */ + BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0), /* A xor X */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_IMM, htobe16(*((unsigned short *) (((char *) eth_mac) + 4)))), /* A <- remainder of client's MAC */ + BPF_STMT(BPF_MISC + BPF_TAX, 0), /* X <- A */ + BPF_STMT(BPF_LD + BPF_H + BPF_ABS, offsetof(DHCPPacket, dhcp.chaddr) + 4), /* A <- remainder of MAC from dhcp.chaddr */ + BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0), /* A xor X */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 1, 0), /* A == 0 ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_LD + BPF_W + BPF_ABS, offsetof(DHCPPacket, dhcp.magic)), /* A <- DHCP magic cookie */ + BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DHCP_MAGIC_COOKIE, 1, 0), /* cookie == DHCP magic cookie ? */ + BPF_STMT(BPF_RET + BPF_K, 0), /* ignore */ + BPF_STMT(BPF_RET + BPF_K, 65535), /* return all */ }; struct sock_fprog fprog = { - .len = ELEMENTSOF(filter), - .filter = filter + .len = ELEMENTSOF(filter), + .filter = filter }; - int s, one = 1; + _cleanup_close_ int s = -1; + int r, on = 1; - assert(index > 0); + assert(ifindex > 0); assert(link); s = socket(AF_PACKET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); if (s < 0) return -errno; + r = setsockopt(s, SOL_PACKET, PACKET_AUXDATA, &on, sizeof(on)); + if (r < 0) + return -errno; + + r = setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog)); + if (r < 0) + return -errno; + link->ll.sll_family = AF_PACKET; link->ll.sll_protocol = htons(ETH_P_IP); - link->ll.sll_ifindex = index; - link->ll.sll_halen = ETH_ALEN; - memset(link->ll.sll_addr, 0xff, ETH_ALEN); + link->ll.sll_ifindex = ifindex; + link->ll.sll_hatype = htons(arp_type); + link->ll.sll_halen = mac_addr_len; + memcpy(link->ll.sll_addr, bcast_addr, mac_addr_len); - if (setsockopt (s, SOL_PACKET, PACKET_AUXDATA, &one, sizeof(one)) < 0) + r = bind(s, &link->sa, sizeof(link->ll)); + if (r < 0) return -errno; - if (setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &fprog, sizeof(fprog)) < 0) { - return -errno; - } + r = s; + s = -1; - if (bind(s, &link->sa, sizeof(link->ll)) < 0) { - safe_close(s); - return -errno; - } + return r; +} - return s; +int dhcp_network_bind_raw_socket(int ifindex, union sockaddr_union *link, + uint32_t xid, const uint8_t *mac_addr, + size_t mac_addr_len, uint16_t arp_type) { + static const uint8_t eth_bcast[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF }; + /* Default broadcast address for IPoIB */ + static const uint8_t ib_bcast[] = { + 0x00, 0xff, 0xff, 0xff, 0xff, 0x12, 0x40, 0x1b, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0xff, 0xff, 0xff, 0xff + }; + struct ether_addr eth_mac = { { 0, 0, 0, 0, 0, 0 } }; + const uint8_t *bcast_addr = NULL; + uint8_t dhcp_hlen = 0; + + assert_return(mac_addr_len > 0, -EINVAL); + + if (arp_type == ARPHRD_ETHER) { + assert_return(mac_addr_len == ETH_ALEN, -EINVAL); + memcpy(ð_mac, mac_addr, ETH_ALEN); + bcast_addr = eth_bcast; + dhcp_hlen = ETH_ALEN; + } else if (arp_type == ARPHRD_INFINIBAND) { + assert_return(mac_addr_len == INFINIBAND_ALEN, -EINVAL); + bcast_addr = ib_bcast; + } else + return -EINVAL; + + return _bind_raw_socket(ifindex, link, xid, mac_addr, mac_addr_len, + bcast_addr, ð_mac, arp_type, dhcp_hlen); } -int dhcp_network_bind_udp_socket(int index, be32_t address, uint16_t port) -{ - int s; +int dhcp_network_bind_udp_socket(be32_t address, uint16_t port) { union sockaddr_union src = { .in.sin_family = AF_INET, .in.sin_port = htobe16(port), .in.sin_addr.s_addr = address, }; + _cleanup_close_ int s = -1; + int r, on = 1, tos = IPTOS_CLASS_CS6; s = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0); if (s < 0) return -errno; - if (bind(s, &src.sa, sizeof(src.in)) < 0) { - safe_close(s); + r = setsockopt(s, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)); + if (r < 0) return -errno; + + r = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); + if (r < 0) + return -errno; + + if (address == INADDR_ANY) { + r = setsockopt(s, IPPROTO_IP, IP_PKTINFO, &on, sizeof(on)); + if (r < 0) + return -errno; + + r = setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)); + if (r < 0) + return -errno; + } else { + r = setsockopt(s, IPPROTO_IP, IP_FREEBIND, &on, sizeof(on)); + if (r < 0) + return -errno; } - return s; + r = bind(s, &src.sa, sizeof(src.in)); + if (r < 0) + return -errno; + + r = s; + s = -1; + + return r; } int dhcp_network_send_raw_socket(int s, const union sockaddr_union *link, - const void *packet, size_t len) -{ + const void *packet, size_t len) { + int r; + assert(link); assert(packet); assert(len); - if (sendto(s, packet, len, 0, &link->sa, sizeof(link->ll)) < 0) + r = sendto(s, packet, len, 0, &link->sa, sizeof(link->ll)); + if (r < 0) return -errno; return 0; } int dhcp_network_send_udp_socket(int s, be32_t address, uint16_t port, - const void *packet, size_t len) -{ + const void *packet, size_t len) { union sockaddr_union dest = { .in.sin_family = AF_INET, .in.sin_port = htobe16(port), .in.sin_addr.s_addr = address, }; + int r; + + assert(s >= 0); + assert(packet); + assert(len); - if (sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in)) < 0) + r = sendto(s, packet, len, 0, &dest.sa, sizeof(dest.in)); + if (r < 0) return -errno; return 0;