libsystemd-network: fix unaligned loads (issue #7654)

should fix https://github.com/systemd/systemd/issues/7654

Also fix up mistaken endianness swap. BPF is native endianness.

diff --git a/src/libsystemd-network/arp-util.c b/src/libsystemd-network/arp-util.c
index 67409cc918e70f9e99acdc8b08d43b58dbec5977..89e68c7ac7f5c29a1e24bcfcd00e3f84eedea494 100644 (file)
--- a/src/libsystemd-network/arp-util.c
+++ b/src/libsystemd-network/arp-util.c
@@ -24,6 +24,7 @@
 
 #include "arp-util.h"
 #include "fd-util.h"
+#include "unaligned.h"
 #include "util.h"
 
 int arp_network_bind_raw_socket(int ifindex, be32_t address, const struct ether_addr *eth_mac) {
@@ -48,12 +49,12 @@ int arp_network_bind_raw_socket(int ifindex, be32_t address, const struct ether_
                 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REPLY, 1, 0),                        /* protocol == reply ? */
                 BPF_STMT(BPF_RET + BPF_K, 0),                                                  /* ignore */
                 /* Sender Hardware Address must be different from our own */
-                BPF_STMT(BPF_LD + BPF_IMM, htobe32(*((uint32_t *) eth_mac))),                  /* A <- 4 bytes of client's MAC */
+                BPF_STMT(BPF_LD + BPF_IMM, unaligned_read_ne32(&eth_mac->ether_addr_octet[0])),/* 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(struct ether_arp, arp_sha)),       /* A <- 4 bytes of SHA */
                 BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0),                                        /* A xor X */
                 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, 0, 0, 6),                                  /* A == 0 ? */
-                BPF_STMT(BPF_LD + BPF_IMM, htobe16(*((uint16_t *) (((char *) eth_mac) + 4)))), /* A <- remainder of client's MAC */
+                BPF_STMT(BPF_LD + BPF_IMM, unaligned_read_ne16(&eth_mac->ether_addr_octet[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(struct ether_arp, arp_sha) + 4),   /* A <- remainder of SHA */
                 BPF_STMT(BPF_ALU + BPF_XOR + BPF_X, 0),                                        /* A xor X */

diff --git a/src/libsystemd-network/dhcp-network.c b/src/libsystemd-network/dhcp-network.c
index 010090aef1cb96e62c0d1160802d33cd3c65d77a..602bf08a6033d7baa7edcb83154c1b7fb830822a 100644 (file)
--- a/src/libsystemd-network/dhcp-network.c
+++ b/src/libsystemd-network/dhcp-network.c
@@ -32,6 +32,7 @@
 #include "dhcp-internal.h"
 #include "fd-util.h"
 #include "socket-util.h"
+#include "unaligned.h"
 
 static int _bind_raw_socket(int ifindex, union sockaddr_union *link,
                             uint32_t xid, const uint8_t *mac_addr,
@@ -70,13 +71,13 @@ static int _bind_raw_socket(int ifindex, union sockaddr_union *link,
                 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_LD + BPF_IMM, unaligned_read_be32(&eth_mac->ether_addr_octet[0])),        /* 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_LD + BPF_IMM, unaligned_read_be16(&eth_mac->ether_addr_octet[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 */