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mirror of https://gitlab.com/libvirt/libvirt.git synced 2025-03-07 17:28:15 +00:00

util: make virSocketAddrIPv4 a union

virSocketAddrIPv4 is a type used only internally by
virsocketaddr.c. It is defined to be a character array, which leads to
multiple occurences of extra bit fiddling and byte swapping for no
good reason (except to confuse).

An IPv4 address is really just a uint32_t with the bytes in network
order, which is exactly the type of the s_addr member of the
sockaddr_in that is a part of the publicly consumed struct
virSocketAddr, and that we are copying in and out of a
virSocketAddrIPv4. Sometimes it's simpler to just treat it as a
network-order uint32_t, so let's make our virSocketAddrIPv4 a union
that has both an unsigned char bytes[4] (for the times when we need to
look one byte at a time) and a uint32_t val (for the times when it's
simpler to treat it as a single value).

For now we just change all the uses from, e.g. x[i] to x.bytes[y];
an upcoming patch will simplify some of the code to remove loops by
using x.val instead of x.bytes when appropriate.

Signed-off-by: Laine Stump <laine@redhat.com>
This commit is contained in:
Laine Stump 2024-08-08 21:09:43 -04:00
parent 14623a3424
commit 009464902a

View File

@ -28,7 +28,11 @@
* Helpers to extract the IP arrays from the virSocketAddr * * Helpers to extract the IP arrays from the virSocketAddr *
* That part is the less portable of the module * That part is the less portable of the module
*/ */
typedef unsigned char virSocketAddrIPv4[4]; typedef union {
uint32_t val;
unsigned char bytes[4];
} virSocketAddrIPv4;
typedef unsigned short virSocketAddrIPv6[8]; typedef unsigned short virSocketAddrIPv6[8];
typedef unsigned char virSocketAddrIPv6Bytes[16]; typedef unsigned char virSocketAddrIPv6Bytes[16];
typedef unsigned char virSocketAddrIPv6Nibbles[32]; typedef unsigned char virSocketAddrIPv6Nibbles[32];
@ -46,7 +50,7 @@ virSocketAddrGetIPv4Addr(const virSocketAddr *addr,
val = ntohl(addr->data.inet4.sin_addr.s_addr); val = ntohl(addr->data.inet4.sin_addr.s_addr);
for (i = 0; i < 4; i++) { for (i = 0; i < 4; i++) {
(*tab)[3 - i] = val & 0xFF; tab->bytes[3 - i] = val & 0xFF;
val >>= 8; val >>= 8;
} }
@ -838,7 +842,7 @@ int virSocketAddrCheckNetmask(virSocketAddr *addr1, virSocketAddr *addr2,
return -1; return -1;
for (i = 0; i < 4; i++) { for (i = 0; i < 4; i++) {
if ((t1[i] & tm[i]) != (t2[i] & tm[i])) if ((t1.bytes[i] & tm.bytes[i]) != (t2.bytes[i] & tm.bytes[i]))
return 0; return 0;
} }
@ -986,14 +990,14 @@ virSocketAddrGetRange(virSocketAddr *start, virSocketAddr *end,
* are the same * are the same
*/ */
for (i = 0; i < 2; i++) { for (i = 0; i < 2; i++) {
if (t1[i] != t2[i]) { if (t1.bytes[i] != t2.bytes[i]) {
virReportError(VIR_ERR_INTERNAL_ERROR, virReportError(VIR_ERR_INTERNAL_ERROR,
_("range %1$s - %2$s is too large (> 65535)"), _("range %1$s - %2$s is too large (> 65535)"),
startStr, endStr); startStr, endStr);
return -1; return -1;
} }
} }
ret = (t2[2] - t1[2]) * 256 + (t2[3] - t1[3]); ret = (t2.bytes[2] - t1.bytes[2]) * 256 + (t2.bytes[3] - t1.bytes[3]);
if (ret < 0) { if (ret < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, virReportError(VIR_ERR_INTERNAL_ERROR,
_("range %1$s - %2$s is reversed "), _("range %1$s - %2$s is reversed "),
@ -1064,7 +1068,7 @@ int virSocketAddrGetNumNetmaskBits(const virSocketAddr *netmask)
return -1; return -1;
for (i = 0; i < 4; i++) for (i = 0; i < 4; i++)
if (tm[i] == 0xff) if (tm.bytes[i] == 0xff)
c += 8; c += 8;
else else
break; break;
@ -1075,7 +1079,7 @@ int virSocketAddrGetNumNetmaskBits(const virSocketAddr *netmask)
j = i << 3; j = i << 3;
while (j < (8 * 4)) { while (j < (8 * 4)) {
bit = 1 << (7 - (j & 7)); bit = 1 << (7 - (j & 7));
if ((tm[j >> 3] & bit)) if ((tm.bytes[j >> 3] & bit))
c++; c++;
else else
break; break;
@ -1084,7 +1088,7 @@ int virSocketAddrGetNumNetmaskBits(const virSocketAddr *netmask)
while (j < (8 * 4)) { while (j < (8 * 4)) {
bit = 1 << (7 - (j & 7)); bit = 1 << (7 - (j & 7));
if ((tm[j >> 3] & bit)) if ((tm.bytes[j >> 3] & bit))
return -1; return -1;
j++; j++;
} }
@ -1326,7 +1330,7 @@ virSocketAddrPTRDomain(const virSocketAddr *addr,
return -1; return -1;
for (i = prefix / 8; i > 0; i--) for (i = prefix / 8; i > 0; i--)
virBufferAsprintf(&buf, "%u.", ip[i - 1]); virBufferAsprintf(&buf, "%u.", ip.bytes[i - 1]);
virBufferAddLit(&buf, VIR_SOCKET_ADDR_IPV4_ARPA); virBufferAddLit(&buf, VIR_SOCKET_ADDR_IPV4_ARPA);
} else if (VIR_SOCKET_ADDR_IS_FAMILY(addr, AF_INET6)) { } else if (VIR_SOCKET_ADDR_IS_FAMILY(addr, AF_INET6)) {
@ -1389,7 +1393,7 @@ virSocketAddrBytes(const virSocketAddr *addr,
return 0; return 0;
virSocketAddrGetIPv4Addr(addr, &ip); virSocketAddrGetIPv4Addr(addr, &ip);
memcpy(bytes, ip, sizeof(ip)); memcpy(bytes, &ip, sizeof(ip));
return sizeof(ip); return sizeof(ip);
} }