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socket: Introduce API osmo_sock_init2_multiaddr() 

This API will be used by libosmo-netif's osmo_stream for SCTP sockets,
which in turn will be used by libosmo-sccp to support multi-homed
connections.

Related: OS#3608
Change-Id: Ic8681d9e093216c99c6bca4be81c31ef83688ed1
This commit is contained in:
Pau Espin 2019-10-10 17:38:35 +02:00 committed by laforge
parent c85f773640
commit 3f464fc007
5 changed files with 307 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
configure.ac
View File

@ -100,6 +100,17 @@ AC_SUBST(SYMBOL_VISIBILITY)
AC_CHECK_FUNCS(clock_gettime localtime_r)
old_LIBS=$LIBS
AC_SEARCH_LIBS([sctp_bindx], [sctp], [
AC_DEFINE(HAVE_LIBSCTP, 1, [Define 1 to enable SCTP support])
AC_SUBST(HAVE_LIBSCTP, [1])
if test -n "$ac_lib"; then
AC_SUBST(LIBSCTP_LIBS, [-l$ac_lib])
fi
], [
AC_MSG_WARN([sctp_bindx not found in searched libs])])
LIBS=$old_LIBS
AC_DEFUN([CHECK_TM_INCLUDES_TM_GMTOFF], [
AC_CACHE_CHECK(
[whether struct tm has tm_gmtoff member],

1
debian/control vendored
View File

@ -15,6 +15,7 @@ Build-Depends: debhelper (>= 9),
libpcsclite-dev,
pkg-config,
libtalloc-dev,
libsctp-dev,
python (>= 2.7.6)
Standards-Version: 3.9.8
Vcs-Git: git://git.osmocom.org/libosmocore.git

7
include/osmocom/core/socket.h
View File

@ -36,6 +36,9 @@ struct osmo_fd;
/*! use SO_REUSEADDR on UDP ports (required for multicast) */
#define OSMO_SOCK_F_UDP_REUSEADDR (1 << 5)
/*! maximum number of local or remote addresses supported by an osmo_sock instance */
#define OSMO_SOCK_MAX_ADDRS 32
int osmo_sock_init(uint16_t family, uint16_t type, uint8_t proto,
const char *host, uint16_t port, unsigned int flags);
@ -43,6 +46,10 @@ int osmo_sock_init2(uint16_t family, uint16_t type, uint8_t proto,
const char *local_host, uint16_t local_port,
const char *remote_host, uint16_t remote_port, unsigned int flags);
int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
const char **local_hosts, size_t local_hosts_cnt, uint16_t local_port,
const char **remote_hosts, size_t remote_hosts_cnt, uint16_t remote_port, unsigned int flags);
int osmo_sock_init_ofd(struct osmo_fd *ofd, int family, int type, int proto,
const char *host, uint16_t port, unsigned int flags);

4
src/Makefile.am
View File

@ -4,7 +4,7 @@
LIBVERSION=14:0:2
AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include
AM_CFLAGS = -Wall $(TALLOC_CFLAGS) $(PTHREAD_CFLAGS)
AM_CFLAGS = -Wall $(TALLOC_CFLAGS) $(PTHREAD_CFLAGS) $(LIBSCTP_CFLAGS)
if ENABLE_PSEUDOTALLOC
AM_CPPFLAGS += -I$(top_srcdir)/src/pseudotalloc
@ -12,7 +12,7 @@ endif
lib_LTLIBRARIES = libosmocore.la
libosmocore_la_LIBADD = $(BACKTRACE_LIB) $(TALLOC_LIBS) $(LIBRARY_RT) $(PTHREAD_LIBS)
libosmocore_la_LIBADD = $(BACKTRACE_LIB) $(TALLOC_LIBS) $(LIBRARY_RT) $(PTHREAD_LIBS) $(LIBSCTP_LIBS)
libosmocore_la_SOURCES = context.c timer.c timer_gettimeofday.c timer_clockgettime.c \
select.c signal.c msgb.c bits.c \
bitvec.c bitcomp.c counter.c fsm.c \

286
src/socket.c
View File

@ -53,6 +53,10 @@
#include <netdb.h>
#include <ifaddrs.h>
#ifdef HAVE_LIBSCTP
#include <netinet/sctp.h>
#endif
static struct addrinfo *addrinfo_helper(uint16_t family, uint16_t type, uint8_t proto,
const char *host, uint16_t port, bool passive)
{
@ -96,6 +100,34 @@ static struct addrinfo *addrinfo_helper(uint16_t family, uint16_t type, uint8_t
return result;
}
/*! Retrieve an array of addrinfo with specified hints, one for each host in the hosts array.
* \param[out] addrinfo array of addrinfo pointers, will be filled by the function on success.
* Its size must be at least the one of hosts.
* \param[in] family Socket family like AF_INET, AF_INET6.
* \param[in] type Socket type like SOCK_DGRAM, SOCK_STREAM.
* \param[in] proto Protocol like IPPROTO_TCP, IPPROTO_UDP.
* \param[in] hosts array of char pointers (strings) containing the addresses to query.
* \param[in] host_cnt length of the hosts array (in items).
* \param[in] port port number in host byte order.
* \param[in] passive whether to include the AI_PASSIVE flag in getaddrinfo() hints.
* \returns 0 is returned on success together with a filled addrinfo array; negative on error
*/
static int addrinfo_helper_multi(struct addrinfo **addrinfo, uint16_t family, uint16_t type, uint8_t proto,
const char **hosts, size_t host_cnt, uint16_t port, bool passive)
{
int i, j;
for (i = 0; i < host_cnt; i++) {
addrinfo[i] = addrinfo_helper(family, type, proto, hosts[i], port, passive);
if (!addrinfo[i]) {
for (j = 0; j < i; j++)
freeaddrinfo(addrinfo[j]);
return -EINVAL;
}
}
return 0;
}
static int socket_helper(const struct addrinfo *rp, unsigned int flags)
{
int sfd, on = 1;
@ -118,6 +150,37 @@ static int socket_helper(const struct addrinfo *rp, unsigned int flags)
return sfd;
}
/* Fill buf with a string representation of the address set, in the form:
* buf_len == 0: "()"
* buf_len == 1: "hostA"
* buf_len >= 2: (hostA|hostB|...|...)
*/
static int multiaddr_snprintf(char* buf, size_t buf_len, const char **hosts, size_t host_cnt)
{
int len = 0, offset = 0, rem = buf_len;
int ret, i;
char *after;
if (buf_len < 3)
return -EINVAL;
if (host_cnt != 1) {
ret = snprintf(buf, rem, "(");
if (ret < 0)
return ret;
OSMO_SNPRINTF_RET(ret, rem, offset, len);
}
for (i = 0; i < host_cnt; i++) {
if (host_cnt == 1)
after = "";
else
after = (i == (host_cnt - 1)) ? ")" : "|";
ret = snprintf(buf + offset, rem, "%s%s", hosts[i] ? : "0.0.0.0", after);
OSMO_SNPRINTF_RET(ret, rem, offset, len);
}
return len;
}
static int osmo_sock_init_tail(int fd, uint16_t type, unsigned int flags)
{
@ -294,6 +357,229 @@ int osmo_sock_init2(uint16_t family, uint16_t type, uint8_t proto,
return sfd;
}
#ifdef HAVE_LIBSCTP
/* Build array of addresses taking first addrinfo result of the requested family
* for each host in hosts. addrs4 or addrs6 are filled based on family type. */
static int addrinfo_to_sockaddr(uint16_t family, const struct addrinfo **result,
const char **hosts, int host_cont,
struct sockaddr_in *addrs4, struct sockaddr_in6 *addrs6) {
size_t host_idx;
const struct addrinfo *rp;
OSMO_ASSERT(family == AF_INET || family == AF_INET6);
for (host_idx = 0; host_idx < host_cont; host_idx++) {
for (rp = result[host_idx]; rp != NULL; rp = rp->ai_next) {
if (rp->ai_family != family)
continue;
if (family == AF_INET)
memcpy(&addrs4[host_idx], rp->ai_addr, sizeof(addrs4[host_idx]));
else
memcpy(&addrs6[host_idx], rp->ai_addr, sizeof(addrs6[host_idx]));
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;
}
}
return 0;
}
/*! Initialize a socket (including bind and/or connect) with multiple local or remote addresses.
* \param[in] family Address Family like AF_INET, AF_INET6, AF_UNSPEC
* \param[in] type Socket type like SOCK_DGRAM, SOCK_STREAM
* \param[in] proto Protocol like IPPROTO_TCP, IPPROTO_UDP
* \param[in] local_hosts array of char pointers (strings), each containing local host name or IP address in string form
* \param[in] local_hosts_cnt length of local_hosts (in items)
* \param[in] local_port local port number in host byte order
* \param[in] remote_host array of char pointers (strings), each containing remote host name or IP address in string form
* \param[in] remote_hosts_cnt length of remote_hosts (in items)
* \param[in] remote_port remote port number in host byte order
* \param[in] flags flags like \ref OSMO_SOCK_F_CONNECT
* \returns socket file descriptor on success; negative on error
*
* This function is similar to \ref osmo_sock_init2(), but can be passed an
* array of local or remote addresses for protocols supporting multiple
* addresses per socket, like SCTP (currently only one supported). This function
* should not be used by protocols not supporting this kind of features, but
* rather \ref osmo_sock_init2() should be used instead.
* See \ref osmo_sock_init2() for more information on flags and general behavior.
*/
int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
const char **local_hosts, size_t local_hosts_cnt, uint16_t local_port,
const char **remote_hosts, size_t remote_hosts_cnt, uint16_t remote_port,
unsigned int flags)
{
struct addrinfo *result[OSMO_SOCK_MAX_ADDRS];
int sfd = -1, rc, on = 1;
int i;
struct sockaddr_in addrs4[OSMO_SOCK_MAX_ADDRS];
struct sockaddr_in6 addrs6[OSMO_SOCK_MAX_ADDRS];
struct sockaddr *addrs;
char strbuf[512];
/* 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)
return -ENOTSUP;
/* TODO: Let's not support AF_UNSPEC for now. sctp_bindx() actually
supports binding both types of addresses on a AF_INET6 soscket, but
that would mean we could get both AF_INET and AF_INET6 addresses for
each host, and makes complexity of this function increase a lot since
we'd need to find out which subsets to use, use v4v6 mapped socket,
etc. */
if (family == AF_UNSPEC)
return -ENOTSUP;
if ((flags & (OSMO_SOCK_F_BIND | OSMO_SOCK_F_CONNECT)) == 0) {
LOGP(DLGLOBAL, LOGL_ERROR, "invalid: you have to specify either "
"BIND or CONNECT flags\n");
return -EINVAL;
}
if (((flags & OSMO_SOCK_F_BIND) && !local_hosts_cnt) ||
((flags & OSMO_SOCK_F_CONNECT) && !remote_hosts_cnt) ||
local_hosts_cnt > OSMO_SOCK_MAX_ADDRS ||
remote_hosts_cnt > OSMO_SOCK_MAX_ADDRS)
return -EINVAL;
/* figure out local side of socket */
if (flags & OSMO_SOCK_F_BIND) {
rc = addrinfo_helper_multi(result, family, type, proto, local_hosts,
local_hosts_cnt, local_port, true);
if (rc < 0)
return -EINVAL;
/* Since addrinfo_helper sets ai_family, socktype and
ai_protocol in hints, we know all results will use same
values, so simply pick the first one and pass it to create
the socket:
*/
sfd = socket_helper(result[0], flags);
if (sfd < 0) {
for (i = 0; i < local_hosts_cnt; i++)
freeaddrinfo(result[i]);
return sfd;
}
if (proto != IPPROTO_UDP || flags & OSMO_SOCK_F_UDP_REUSEADDR) {
rc = setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR,
&on, sizeof(on));
if (rc < 0) {
multiaddr_snprintf(strbuf, sizeof(strbuf), local_hosts, local_hosts_cnt);
LOGP(DLGLOBAL, LOGL_ERROR,
"cannot setsockopt socket:"
" %s:%u: %s\n",
strbuf, local_port,
strerror(errno));
for (i = 0; i < local_hosts_cnt; i++)
freeaddrinfo(result[i]);
close(sfd);
return rc;
}
}
/* Build array of addresses taking first of same family for each host.
TODO: Ideally we should use backtracking storing last used
indexes and trying next combination if connect() fails .*/
rc = addrinfo_to_sockaddr(family, (const struct addrinfo **)result,
local_hosts, local_hosts_cnt, addrs4, addrs6);
if (rc < 0) {
for (i = 0; i < local_hosts_cnt; i++)
freeaddrinfo(result[i]);
close(sfd);
return -ENODEV;
}
if (family == AF_INET)
addrs = (struct sockaddr *)addrs4;
else
addrs = (struct sockaddr *)addrs6;
if (sctp_bindx(sfd, addrs, local_hosts_cnt, SCTP_BINDX_ADD_ADDR) == -1) {
multiaddr_snprintf(strbuf, sizeof(strbuf), local_hosts, local_hosts_cnt);
LOGP(DLGLOBAL, LOGL_NOTICE, "unable to bind socket: %s:%u: %s\n",
strbuf, local_port, strerror(errno));
for (i = 0; i < local_hosts_cnt; i++)
freeaddrinfo(result[i]);
close(sfd);
return -ENODEV;
}
for (i = 0; i < local_hosts_cnt; i++)
freeaddrinfo(result[i]);
}
/* Reached this point, if OSMO_SOCK_F_BIND then sfd is valid (>=0) or it
was already closed and func returned. If OSMO_SOCK_F_BIND is not
set, then sfd = -1 */
/* figure out remote side of socket */
if (flags & OSMO_SOCK_F_CONNECT) {
rc = addrinfo_helper_multi(result, family, type, proto, remote_hosts,
remote_hosts_cnt, remote_port, false);
if (rc < 0) {
if (sfd >= 0)
close(sfd);
return -EINVAL;
}
if (sfd < 0) {
/* Since addrinfo_helper sets ai_family, socktype and
ai_protocol in hints, we know all results will use same
values, so simply pick the first one and pass it to create
the socket:
*/
sfd = socket_helper(result[0], flags);
if (sfd < 0) {
for (i = 0; i < remote_hosts_cnt; i++)
freeaddrinfo(result[i]);
return sfd;
}
}
/* Build array of addresses taking first of same family for each host.
TODO: Ideally we should use backtracking storing last used
indexes and trying next combination if connect() fails .*/
rc = addrinfo_to_sockaddr(family, (const struct addrinfo **)result,
remote_hosts, remote_hosts_cnt, addrs4, addrs6);
if (rc < 0) {
for (i = 0; i < remote_hosts_cnt; i++)
freeaddrinfo(result[i]);
close(sfd);
return -ENODEV;
}
if (family == AF_INET)
addrs = (struct sockaddr *)addrs4;
else
addrs = (struct sockaddr *)addrs6;
rc = sctp_connectx(sfd, addrs, remote_hosts_cnt, NULL);
if (rc != 0 && errno != EINPROGRESS) {
multiaddr_snprintf(strbuf, sizeof(strbuf), remote_hosts, remote_hosts_cnt);
LOGP(DLGLOBAL, LOGL_ERROR, "unable to connect socket: %s:%u: %s\n",
strbuf, remote_port, strerror(errno));
for (i = 0; i < remote_hosts_cnt; i++)
freeaddrinfo(result[i]);
close(sfd);
return -ENODEV;
}
for (i = 0; i < remote_hosts_cnt; i++)
freeaddrinfo(result[i]);
}
rc = osmo_sock_init_tail(sfd, type, flags);
if (rc < 0) {
close(sfd);
sfd = -1;
}
return sfd;
}
#endif /* HAVE_LIBSCTP */
/*! Initialize a socket (including bind/connect)
* \param[in] family Address Family like AF_INET, AF_INET6, AF_UNSPEC