// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2009, Oracle. All rights reserved.
*
* Convert socket addresses to presentation addresses and universal
* addresses, and vice versa.
*
* Universal addresses are introduced by RFC 1833 and further refined by
* recent RFCs describing NFSv4. The universal address format is part
* of the external (network) interface provided by rpcbind version 3
* and 4, and by NFSv4. Such an address is a string containing a
* presentation format IP address followed by a port number in
* "hibyte.lobyte" format.
*
* IPv6 addresses can also include a scope ID, typically denoted by
* a '%' followed by a device name or a non-negative integer. Refer to
* RFC 4291, Section 2.2 for details on IPv6 presentation formats.
*/
#include <net/ipv6.h>
#include <linux/sunrpc/addr.h>
#include <linux/sunrpc/msg_prot.h>
#include <linux/slab.h>
#include <linux/export.h>
#if IS_ENABLED(CONFIG_IPV6)
static size_t rpc_ntop6_noscopeid(const struct sockaddr *sap,
char *buf, const int buflen)
{
const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
const struct in6_addr *addr = &sin6->sin6_addr;
/*
* RFC 4291, Section 2.2.2
*
* Shorthanded ANY address
*/
if (ipv6_addr_any(addr))
return snprintf(buf, buflen, "::");
/*
* RFC 4291, Section 2.2.2
*
* Shorthanded loopback address
*/
if (ipv6_addr_loopback(addr))
return snprintf(buf, buflen, "::1");
/*
* RFC 4291, Section 2.2.3
*
* Special presentation address format for mapped v4
* addresses.
*/
if (ipv6_addr_v4mapped(addr))
return snprintf(buf, buflen, "::ffff:%pI4",
&addr->s6_addr32[3]);
/*
* RFC 4291, Section 2.2.1
*/
return snprintf(buf, buflen, "%pI6c", addr);
}
static size_t rpc_ntop6(const struct sockaddr *sap,
char *buf, const size_t buflen)
{
const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
char scopebuf[IPV6_SCOPE_ID_LEN];
size_t len;
int rc;
len = rpc_ntop6_noscopeid(sap, buf, buflen);
if (unlikely(len == 0))
return len;
if (!(ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL))
return len;
if (sin6->sin6_scope_id == 0)
return len;
rc = snprintf(scopebuf, sizeof(scopebuf), "%c%u",
IPV6_SCOPE_DELIMITER, sin6->sin6_scope_id);
if (unlikely((size_t)rc >= sizeof(scopebuf)))
return 0;
len += rc;
if (unlikely(len >= buflen))
return 0;
strcat(buf, scopebuf);
return len;
}
#else /* !IS_ENABLED(CONFIG_IPV6) */
static size_t rpc_ntop6_noscopeid(const struct sockaddr *sap,
char *buf, const int buflen)
{
return 0;
}
static size_t rpc_ntop6(const struct sockaddr *sap,
char *buf, const size_t buflen)
{
return 0;
}
#endif /* !IS_ENABLED(CONFIG_IPV6) */
static int rpc_ntop4(const struct sockaddr *sap,
char *buf, const size_t buflen)
{
const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
}
/**
* rpc_ntop - construct a presentation address in @buf
* @sap: socket address
* @buf: construction area
* @buflen: size of @buf, in bytes
*
* Plants a %NUL-terminated string in @buf and returns the length
* of the string, excluding the %NUL. Otherwise zero is returned.
*/
size_t rpc_ntop(const struct sockaddr *sap, char *buf, const size_t buflen)
{
switch (sap->sa_family) {
case AF_INET:
return rpc_ntop4(sap, buf, buflen);
case AF_INET6:
return rpc_ntop6(sap, buf, buflen);
}
return 0;
}
EXPORT_SYMBOL_GPL(rpc_ntop);
static size_t rpc_pton4(const char *buf, const size_t buflen,
struct sockaddr *sap, const size_t salen)
{
struct sockaddr_in *sin = (struct sockaddr_in *)sap;
u8 *addr = (u8 *)&sin->sin_addr.s_addr;
if (buflen > INET_ADDRSTRLEN || salen < sizeof(struct sockaddr_in))
return 0;
memset(sap, 0, sizeof(struct sockaddr_in));
if (in4_pton(buf, buflen, addr, '\0', NULL) == 0)
return 0;
sin->sin_family = AF_INET;
return sizeof(struct sockaddr_in);
}
#if IS_ENABLED(CONFIG_IPV6)
static int rpc_parse_scope_id(struct net *net, const char *buf,
const size_t buflen, const char *delim,
struct sockaddr_in6 *sin6)
{
char p[IPV6_SCOPE_ID_LEN + 1];
size_t len;
u32 scope_id = 0;
struct net_device *dev;
if ((buf + buflen) == delim)
return 1;
if (*delim != IPV6_SCOPE_DELIMITER)
return 0;
if (!(ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL))
return 0;
len = (buf + buflen) - delim - 1;
if (len > IPV6_SCOPE_ID_LEN)
return 0;
memcpy(p, delim + 1, len);
p[len] = 0;
dev = dev_get_by_name(net, p);
if (dev != NULL) {
scope_id = dev->ifindex;
dev_put(dev);
} else {
if (kstrtou32(p, 10, &scope_id) != 0)
return 0;
}
sin6->sin6_scope_id = scope_id;
return 1;
}
static size_t rpc_pton6(struct net *net, const char *buf, const size_t buflen,
struct sockaddr *sap, const size_t salen)
{
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
u8 *addr = (u8 *)&sin6->sin6_addr.in6_u;
const char *delim;
if (buflen > (INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN) ||
salen < sizeof(struct sockaddr_in6))
return 0;
memset(sap, 0, sizeof(struct sockaddr_in6));
if (in6_pton(buf, buflen, addr, IPV6_SCOPE_DELIMITER, &delim) == 0)
return 0;
if (!rpc_parse_scope_id(net, buf, buflen, delim, sin6))
return 0;
sin6->sin6_family = AF_INET6;
return sizeof(struct sockaddr_in6);
}
#else
static size_t rpc_pton6(struct net *net, const char *buf, const size_t buflen,
struct sockaddr *sap, const size_t salen)
{
return 0;
}
#endif
/**
* rpc_pton - Construct a sockaddr in @sap
* @net: applicable network namespace
* @buf: C string containing presentation format IP address
* @buflen: length of presentation address in bytes
* @sap: buffer into which to plant socket address
* @salen: size of buffer in bytes
*
* Returns the size of the socket address if successful; otherwise
* zero is returned.
*
* Plants a socket address in @sap and returns the size of the
* socket address, if successful. Returns zero if an error
* occurred.
*/
size_t rpc_pton(struct net *net, const char *buf, const size_t buflen,
struct sockaddr *sap, const size_t salen)
{
unsigned int i;
for (i = 0; i < buflen; i++)
if (buf[i] == ':')
return rpc_pton6(net, buf, buflen, sap, salen);
return rpc_pton4(buf, buflen, sap, salen);
}
EXPORT_SYMBOL_GPL(rpc_pton);
/**
* rpc_sockaddr2uaddr - Construct a universal address string from @sap.
* @sap: socket address
* @gfp_flags: allocation mode
*
* Returns a %NUL-terminated string in dynamically allocated memory;
* otherwise NULL is returned if an error occurred. Caller must
* free the returned string.
*/
char *rpc_sockaddr2uaddr(const struct sockaddr *sap, gfp_t gfp_flags)
{
char portbuf[RPCBIND_MAXUADDRPLEN];
char addrbuf[RPCBIND_MAXUADDRLEN];
unsigned short port;
switch (sap->sa_family) {
case AF_INET:
if (rpc_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
return NULL;
port = ntohs(((struct sockaddr_in *)sap)->sin_port);
break;
case AF_INET6:
if (rpc_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
return NULL;
port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
break;
default:
return NULL;
}
if (snprintf(portbuf, sizeof(portbuf),
".%u.%u", port >> 8, port & 0xff) >= (int)sizeof(portbuf))
return NULL;
if (strlcat(addrbuf, portbuf, sizeof(addrbuf)) >= sizeof(addrbuf))
return NULL;
return kstrdup(addrbuf, gfp_flags);
}
/**
* rpc_uaddr2sockaddr - convert a universal address to a socket address.
* @net: applicable network namespace
* @uaddr: C string containing universal address to convert
* @uaddr_len: length of universal address string
* @sap: buffer into which to plant socket address
* @salen: size of buffer
*
* @uaddr does not have to be '\0'-terminated, but kstrtou8() and
* rpc_pton() require proper string termination to be successful.
*
* Returns the size of the socket address if successful; otherwise
* zero is returned.
*/
size_t rpc_uaddr2sockaddr(struct net *net, const char *uaddr,
const size_t uaddr_len, struct sockaddr *sap,
const size_t salen)
{
char *c, buf[RPCBIND_MAXUADDRLEN + sizeof('\0')];
u8 portlo, porthi;
unsigned short port;
if (uaddr_len > RPCBIND_MAXUADDRLEN)
return 0;
memcpy(buf, uaddr, uaddr_len);
buf[uaddr_len] = '\0';
c = strrchr(buf, '.');
if (unlikely(c == NULL))
return 0;
if (unlikely(kstrtou8(c + 1, 10, &portlo) != 0))
return 0;
*c = '\0';
c = strrchr(buf, '.');
if (unlikely(c == NULL))
return 0;
if (unlikely(kstrtou8(c + 1, 10, &porthi) != 0))
return 0;
port = (unsigned short)((porthi << 8) | portlo);
*c = '\0';
if (rpc_pton(net, buf, strlen(buf), sap, salen) == 0)
return 0;
switch (sap->sa_family) {
case AF_INET:
((struct sockaddr_in *)sap)->sin_port = htons(port);
return sizeof(struct sockaddr_in);
case AF_INET6:
((struct sockaddr_in6 *)sap)->sin6_port = htons(port);
return sizeof(struct sockaddr_in6);
}
return 0;
}
EXPORT_SYMBOL_GPL(rpc_uaddr2sockaddr);
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