chiark / gitweb /
sd-network: make socket filter programs static const where possible
[elogind.git] / src / libsystemd-network / dhcp-network.c
index 29276c0559b07a90213a95da9cb5395ff26d5b41..1ced5cf292adc84e65d211fbddc799d022c2f59c 100644 (file)
 
 #include "dhcp-internal.h"
 
-int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link,
+int dhcp_network_bind_raw_socket(int ifindex, union sockaddr_union *link,
                                  uint32_t xid, struct ether_addr mac_addr) {
+
         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_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, ARPHRD_ETHER, 1, 0),               /* header type == ARPHRD_ETHER ? */
-            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, ETHER_ADDR_LEN, 1, 0),             /* address length == ETHER_ADDR_LEN ? */
-            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 *) &mac_addr))),                    /* 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 *) &mac_addr) + 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 */
+                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, ARPHRD_ETHER, 1, 0),               /* header type == ARPHRD_ETHER ? */
+                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, ETHER_ADDR_LEN, 1, 0),             /* address length == ETHER_ADDR_LEN ? */
+                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 *) &mac_addr))),                    /* 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 *) &mac_addr) + 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
         };
         _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));
+        r = setsockopt(s, SOL_PACKET, PACKET_AUXDATA, &on, sizeof(on));
         if (r < 0)
                 return -errno;
 
@@ -105,7 +106,7 @@ int dhcp_network_bind_raw_socket(int index, union sockaddr_union *link,
 
         link->ll.sll_family = AF_PACKET;
         link->ll.sll_protocol = htons(ETH_P_IP);
-        link->ll.sll_ifindex =  index;
+        link->ll.sll_ifindex = ifindex;
         link->ll.sll_halen = ETH_ALEN;
         memset(link->ll.sll_addr, 0xff, ETH_ALEN);