net: Use packed structures for networking
PXE boot is broken with GCC 7.1 due option '-fstore-merging' enabled
by default for '-O2':
BOOTP broadcast 1
data abort
pc : [<8ff8bb30>] lr : [<00004f1f>]
reloc pc : [<17832b30>] lr : [<878abf1f>]
sp : 8f558bc0 ip : 00000000 fp : 8ffef5a4
r10: 8ffed248 r9 : 8f558ee0 r8 : 8ffef594
r7 : 0000000e r6 : 8ffed700 r5 : 00000000 r4 : 8ffed74e
r3 : 00060101 r2 : 8ffed230 r1 : 8ffed706 r0 : 00000ddd
Flags: nzcv IRQs off FIQs off Mode SVC_32
Resetting CPU ...
Core reason is usage of structures for network headers without packed
attribute.
Reviewed-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/include/net.h b/include/net.h
index 2eaa882..e126948 100644
--- a/include/net.h
+++ b/include/net.h
@@ -308,7 +308,7 @@
u8 et_dest[ARP_HLEN]; /* Destination node */
u8 et_src[ARP_HLEN]; /* Source node */
u16 et_protlen; /* Protocol or length */
-};
+} __attribute__((packed));
/* Ethernet header size */
#define ETHER_HDR_SIZE (sizeof(struct ethernet_hdr))
@@ -326,7 +326,7 @@
u8 et_snap2;
u8 et_snap3;
u16 et_prot; /* 802 protocol */
-};
+} __attribute__((packed));
/* 802 + SNAP + ethernet header size */
#define E802_HDR_SIZE (sizeof(struct e802_hdr))
@@ -340,7 +340,7 @@
u16 vet_vlan_type; /* PROT_VLAN */
u16 vet_tag; /* TAG of VLAN */
u16 vet_type; /* protocol type */
-};
+} __attribute__((packed));
/* VLAN Ethernet header size */
#define VLAN_ETHER_HDR_SIZE (sizeof(struct vlan_ethernet_hdr))
@@ -369,7 +369,7 @@
u16 ip_sum; /* checksum */
struct in_addr ip_src; /* Source IP address */
struct in_addr ip_dst; /* Destination IP address */
-};
+} __attribute__((packed));
#define IP_OFFS 0x1fff /* ip offset *= 8 */
#define IP_FLAGS 0xe000 /* first 3 bits */
@@ -397,7 +397,7 @@
u16 udp_dst; /* UDP destination port */
u16 udp_len; /* Length of UDP packet */
u16 udp_xsum; /* Checksum */
-};
+} __attribute__((packed));
#define IP_UDP_HDR_SIZE (sizeof(struct ip_udp_hdr))
#define UDP_HDR_SIZE (IP_UDP_HDR_SIZE - IP_HDR_SIZE)
@@ -435,7 +435,7 @@
u8 ar_tha[]; /* Target hardware address */
u8 ar_tpa[]; /* Target protocol address */
#endif /* 0 */
-};
+} __attribute__((packed));
#define ARP_HDR_SIZE (8+20) /* Size assuming ethernet */
@@ -470,7 +470,7 @@
} frag;
u8 data[0];
} un;
-};
+} __attribute__((packed));
#define ICMP_HDR_SIZE (sizeof(struct icmp_hdr))
#define IP_ICMP_HDR_SIZE (IP_HDR_SIZE + ICMP_HDR_SIZE)