pespin has uploaded this change for review. (
https://gerrit.osmocom.org/c/libosmocore/+/35232?usp=email )
Change subject: Reimplement osmo_sock_init2_multiaddr()
......................................................................
Reimplement osmo_sock_init2_multiaddr()
This is an attempt to fix several downsides of current
osmo_sock_init2_multiaddr() API, mainly the requirement to pass an explicit
local address (!NULL). It also now works fine if OSMO_SOCK_F_BIND flag
is not used.
This reimplementation is based on the follwing logic:
- If caller passed family=AF_INET or family=AF_INET6, that same family
is used and kernel will fail if something is wrong.
- If caller passes family=AF_UNSPEC, the function will try to find the
required family to create the socket. The decision is taken on the
assumption that an AF_INET6 socket can handle both AF_INET6 and AF_INET
addresses (through v4v6 mapping). Hence, if any of the addresses in the
local or remote set of addresses resolves through getaddrinfo() to an
IPv6 address, then AF_INET6 is used; AF_INET is used otherwise.
Related: OS#6279
Change-Id: I2641fbaca6f477404b094dbc53c0c1a3dd3fd2fd
---
M src/core/socket.c
1 file changed, 128 insertions(+), 44 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/32/35232/1
diff --git a/src/core/socket.c b/src/core/socket.c
index 1dc8e46..7873e45 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -616,18 +616,45 @@
#ifdef HAVE_LIBSCTP
-/* Check whether there's an IPv6 Addr as first option of any addrinfo item in
the addrinfo set */
+/* Check whether there's an addrinfo item in the addrinfo set with an IPv4 or
IPv6 option */
static void addrinfo_has_v4v6addr(const struct addrinfo **result, size_t
result_count, bool *has_v4, bool *has_v6)
{
size_t host_idx;
+ const struct addrinfo *rp;
*has_v4 = false;
*has_v6 = false;
for (host_idx = 0; host_idx < result_count; host_idx++) {
- if (result[host_idx]->ai_family == AF_INET)
- *has_v4 = true;
- else if (result[host_idx]->ai_family == AF_INET6)
- *has_v6 = true;
+ for (rp = result[host_idx]; rp != NULL; rp = rp->ai_next) {
+ if (result[host_idx]->ai_family == AF_INET)
+ *has_v4 = true;
+ else if (result[host_idx]->ai_family == AF_INET6)
+ *has_v6 = true;
+ }
+ }
+}
+
+/* Check whether there's an addrinfo item in the addrinfo set with only an
IPv4 or IPv6 option */
+static void addrinfo_has_v4v6only_addr(const struct addrinfo **result, size_t
result_count, bool *has_v4only, bool *has_v6only)
+{
+ size_t host_idx;
+ const struct addrinfo *rp;
+ *has_v4only = false;
+ *has_v6only = false;
+
+ for (host_idx = 0; host_idx < result_count; host_idx++) {
+ bool has_v4 = false;
+ bool has_v6 = false;
+ for (rp = result[host_idx]; rp != NULL; rp = rp->ai_next) {
+ if (rp->ai_family == AF_INET6)
+ has_v6 = true;
+ else
+ has_v4 = true;
+ }
+ if (has_v4 && !has_v6)
+ *has_v4only = true;
+ else if (has_v6 && !has_v4)
+ *has_v6only = true;
}
}
@@ -636,13 +663,16 @@
{
size_t host_idx;
struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
+ const struct addrinfo *rp;
for (host_idx = 0; host_idx < result_count; host_idx++) {
- if (result[host_idx]->ai_family != AF_INET6)
- continue;
- if (memcmp(&((struct sockaddr_in6
*)result[host_idx]->ai_addr)->sin6_addr,
- &in6addr_any, sizeof(in6addr_any)) == 0)
- return true;
+ for (rp = result[host_idx]; rp != NULL; rp = rp->ai_next) {
+ if (rp->ai_family != AF_INET6)
+ continue;
+ if (memcmp(&((struct sockaddr_in6
*)rp->ai_addr)->sin6_addr,
+ &in6addr_any, sizeof(in6addr_any)) == 0)
+ return true;
+ }
}
return false;
}
@@ -676,22 +706,28 @@
for (host_idx = 0; host_idx < host_cont; host_idx++) {
/* Addresses are ordered based on RFC 3484, see man getaddrinfo
*/
for (rp = result[host_idx]; rp != NULL; rp = rp->ai_next) {
- if (family != AF_UNSPEC && rp->ai_family != family)
- continue;
- if (offset + rp->ai_addrlen > addrs_buf_len) {
- LOGP(DLGLOBAL, LOGL_ERROR, "Output buffer to
small: %zu\n",
- addrs_buf_len);
- return -ENOSPC;
+ if (family == AF_UNSPEC || rp->ai_family == family)
+ break;
+ }
+ if (!rp && family == AF_INET6) {
+ /* See if we can find an AF_INET addr for the AF_INET6
socket instead: */
+ for (rp = result[host_idx]; rp != NULL; rp =
rp->ai_next) {
+ if (rp->ai_family == AF_INET)
+ break;
}
- memcpy(addrs_buf + offset, rp->ai_addr, rp->ai_addrlen);
- offset += rp->ai_addrlen;
- break;
}
if (!rp) { /* No addr could be bound for this host! */
LOGP(DLGLOBAL, LOGL_ERROR, "No suitable remote address
found for host: %s\n",
hosts[host_idx]);
return -ENODEV;
}
+ if (offset + rp->ai_addrlen > addrs_buf_len) {
+ LOGP(DLGLOBAL, LOGL_ERROR, "Output buffer to small:
%zu\n",
+ addrs_buf_len);
+ return -ENOSPC;
+ }
+ memcpy(addrs_buf + offset, rp->ai_addr, rp->ai_addrlen);
+ offset += rp->ai_addrlen;
}
return 0;
}
@@ -827,15 +863,13 @@
struct addrinfo *res_loc[OSMO_SOCK_MAX_ADDRS],
*res_rem[OSMO_SOCK_MAX_ADDRS];
int sfd = -1, rc, on = 1;
unsigned int i;
- bool loc_has_v4addr, rem_has_v4addr;
- bool loc_has_v6addr, rem_has_v6addr;
+ bool loc_has_v4addr = false, loc_has_v6addr = false;
+ bool rem_has_v4addr = false, rem_has_v6addr = false;
+ bool loc_has_v4only_addr, rem_has_v4only_addr;
+ bool loc_has_v6only_addr, rem_has_v6only_addr;
struct sockaddr_in6 addrs_buf[OSMO_SOCK_MAX_ADDRS];
char strbuf[512];
- /* updated later in case of AF_UNSPEC */
- loc_has_v4addr = rem_has_v4addr = (family == AF_INET);
- loc_has_v6addr = rem_has_v6addr = (family == AF_INET6);
-
/* TODO: So far this function is only aimed for SCTP, but could be
reused in the future for other protocols with multi-addr support */
if (proto != IPPROTO_SCTP)
@@ -862,10 +896,17 @@
local_hosts_cnt, local_port, true);
if (rc < 0)
return -EINVAL;
- /* Figure out if there's any IPV4 or IPv6 addr in the set */
- if (family == AF_UNSPEC)
- addrinfo_has_v4v6addr((const struct addrinfo
**)res_loc, local_hosts_cnt,
- &loc_has_v4addr, &loc_has_v6addr);
+ /* Figure out if there's any IPv4 or IPv6 entry in the result
set */
+ addrinfo_has_v4v6addr((const struct addrinfo **)res_loc,
local_hosts_cnt,
+ &loc_has_v4addr, &loc_has_v6addr);
+ /* Figure out if there's any IPv4-only or IPv6-only addr in the
result set */
+ addrinfo_has_v4v6only_addr((const struct addrinfo **)res_loc,
local_hosts_cnt,
+ &loc_has_v4only_addr,
&loc_has_v6only_addr);
+ if (family == AF_INET && loc_has_v6only_addr) {
+ LOGP(DLGLOBAL, LOGL_ERROR, "Cannot bind an IPv6 address
to an AF_INET socket\n");
+ rc = -EINVAL;
+ goto ret_freeaddrinfo;
+ }
}
/* figure out remote side of socket */
if (flags & OSMO_SOCK_F_CONNECT) {
@@ -875,26 +916,44 @@
rc = -EINVAL;
goto ret_freeaddrinfo_loc;
}
- /* Figure out if there's any IPv4 or IPv6 addr in the set */
- if (family == AF_UNSPEC)
- addrinfo_has_v4v6addr((const struct addrinfo
**)res_rem, remote_hosts_cnt,
- &rem_has_v4addr, &rem_has_v6addr);
+ /* Figure out if there's any IPv4 or IPv6 entry in the result
set */
+ addrinfo_has_v4v6addr((const struct addrinfo **)res_rem,
remote_hosts_cnt,
+ &rem_has_v4addr, &rem_has_v6addr);
+ /* Figure out if there's any IPv4 or IPv6 addr in the result
set */
+ addrinfo_has_v4v6only_addr((const struct addrinfo **)res_rem,
remote_hosts_cnt,
+ &rem_has_v4only_addr,
&rem_has_v6only_addr);
+ if (family == AF_INET && rem_has_v6only_addr) {
+ LOGP(DLGLOBAL, LOGL_ERROR, "Cannot connect to an IPv6
address in an AF_INET socket\n");
+ rc = -EINVAL;
+ goto ret_freeaddrinfo;
+ }
}
- if (((flags & OSMO_SOCK_F_BIND) && (flags & OSMO_SOCK_F_CONNECT)) &&
- !addrinfo_has_in6addr_any((const struct addrinfo **)res_loc,
local_hosts_cnt) &&
+ /* Find out the socket family now if not established by caller:
+ * Both are checked here through "or" here to account for "bind flag
set,
+ * connect flag not set" and viceversa. */
+ if (family == AF_UNSPEC) {
+ if (!loc_has_v6addr && !rem_has_v6addr)
+ family = AF_INET;
+ else
+ family = AF_INET6;
+ }
+
+ /* if both sets are used, make sure there's at least 1 address of the
+ * same type on each set so that SCTP INIT/INIT-ACK can work. */
+ if (family == AF_INET6 && ((flags & OSMO_SOCK_F_BIND) && (flags &
OSMO_SOCK_F_CONNECT)) &&
(loc_has_v4addr != rem_has_v4addr || loc_has_v6addr !=
rem_has_v6addr)) {
- LOGP(DLGLOBAL, LOGL_ERROR, "Invalid v4 vs v6 in local vs remote
addresses: "
- "local:%s%s remote:%s%s\n",
- loc_has_v4addr ? " v4" : "", loc_has_v6addr ? " v6" : "",
- rem_has_v4addr ? " v4" : "", rem_has_v6addr ? " v6" : ""
- );
- rc = -EINVAL;
- goto ret_freeaddrinfo;
+ if (!addrinfo_has_in6addr_any((const struct addrinfo
**)res_loc, local_hosts_cnt)) {
+ LOGP(DLGLOBAL, LOGL_ERROR, "Invalid v4 vs v6 in local
vs remote addresses: "
+ "local:%s%s remote:%s%s\n",
+ loc_has_v4addr ? " v4" : "", loc_has_v6addr ? "
v6" : "",
+ rem_has_v4addr ? " v4" : "", rem_has_v6addr ? "
v6" : "");
+ rc = -EINVAL;
+ goto ret_freeaddrinfo;
+ }
}
- sfd = socket_helper_multiaddr(loc_has_v6addr ? AF_INET6 : AF_INET,
- type, proto, flags);
+ sfd = socket_helper_multiaddr(family, type, proto, flags);
if (sfd < 0) {
rc = sfd;
goto ret_freeaddrinfo;
--
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Gerrit-Project: libosmocore
Gerrit-Branch: master
Gerrit-Change-Id: I2641fbaca6f477404b094dbc53c0c1a3dd3fd2fd
Gerrit-Change-Number: 35232
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <pes...@sysmocom.de>
Gerrit-MessageType: newchange
