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Add osmo_sock_init2() function, allowing both BIND *and* CONNECT 

The old osmo_sock_init() function allows only either a bind (for a
server socket), or a connect (for a client socket), but not both
together.  So there's no way to have a client socket that is bound to a
specific local IP and/or port, which is needed for some use cases.

Change-Id: Idab124bcca47872f55311a82d6818aed590965e6
This commit is contained in:
Harald Welte 2017-04-08 20:52:33 +02:00
parent acd08feb8f
commit dda70fca79
5 changed files with 248 additions and 33 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
include/osmocom/core/socket.h
View File

@ -24,6 +24,10 @@ struct osmo_fd;
int osmo_sock_init(uint16_t family, uint16_t type, uint8_t proto,
const char *host, uint16_t port, unsigned int flags);
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_init_ofd(struct osmo_fd *ofd, int family, int type, int proto,
const char *host, uint16_t port, unsigned int flags);

220
src/socket.c
View File

@ -51,6 +51,188 @@
#include <netdb.h>
#include <ifaddrs.h>
static struct addrinfo *addrinfo_helper(uint16_t family, uint16_t type, uint8_t proto,
const char *host, uint16_t port, bool passive)
{
struct addrinfo hints, *result;
char portbuf[16];
int rc;
snprintf(portbuf, sizeof(portbuf), "%u", port);
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = family;
if (type == SOCK_RAW) {
/* Workaround for glibc, that returns EAI_SERVICE (-8) if
* SOCK_RAW and IPPROTO_GRE is used.
*/
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = IPPROTO_UDP;
} else {
hints.ai_socktype = type;
hints.ai_protocol = proto;
}
if (passive)
hints.ai_flags |= AI_PASSIVE;
rc = getaddrinfo(host, portbuf, &hints, &result);
if (rc != 0) {
LOGP(DLGLOBAL, LOGL_ERROR, "getaddrinfo returned NULL: %s:%u: %s\n",
host, port, strerror(errno));
return NULL;
}
return result;
}
static int socket_helper(const struct addrinfo *rp, unsigned int flags)
{
int sfd, on = 1;
sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
if (sfd == -1)
return sfd;
if (flags & OSMO_SOCK_F_NONBLOCK) {
if (ioctl(sfd, FIONBIO, (unsigned char *)&on) < 0) {
LOGP(DLGLOBAL, LOGL_ERROR,
"cannot set this socket unblocking: %s\n",
strerror(errno));
close(sfd);
sfd = -EINVAL;
}
}
return sfd;
}
/*! \brief Initialize a socket (including bind and/or connect)
* \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_host local host name or IP address in string form
* \param[in] local_port local port number in host byte order
* \param[in] remote_host remote host name or IP address in string form
* \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 creates a new socket of the designated \a family, \a
* type and \a proto and optionally binds it to the \a local_host and \a
* local_port as well as optionally connects it to the \a remote_host
* and \q remote_port, depending on the value * of \a flags parameter.
*
* As opposed to \ref osmo_sock_init(), this function allows to combine
* the \ref OSMO_SOCK_F_BIND and \ref OSMO_SOCK_F_CONNECT flags. This
* is useful if you want to connect to a remote host/port, but still
* want to bind that socket to either a specific local alias IP and/or a
* specific local source port.
*
* You must specify either \ref OSMO_SOCK_F_BIND, or \ref
* OSMO_SOCK_F_CONNECT, or both.
*
* If \ref OSMO_SOCK_F_NONBLOCK is specified, the socket will be set to
* non-blocking mode.
*/
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)
{
struct addrinfo *result, *rp;
int sfd = -1, rc, on = 1;
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;
}
/* figure out local side of socket */
if (flags & OSMO_SOCK_F_BIND) {
result = addrinfo_helper(family, type, proto, local_host, local_port, true);
if (!result)
return -EINVAL;
for (rp = result; rp != NULL; rp = rp->ai_next) {
/* Workaround for glibc again */
if (type == SOCK_RAW) {
rp->ai_socktype = SOCK_RAW;
rp->ai_protocol = proto;
}
sfd = socket_helper(rp, flags);
if (sfd < 0)
continue;
rc = setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR,
&on, sizeof(on));
if (rc < 0) {
LOGP(DLGLOBAL, LOGL_ERROR,
"cannot setsockopt socket:"
" %s:%u: %s\n",
local_host, local_port, strerror(errno));
break;
}
if (bind(sfd, rp->ai_addr, rp->ai_addrlen) != -1)
break;
close(sfd);
}
freeaddrinfo(result);
if (rp == NULL) {
LOGP(DLGLOBAL, LOGL_ERROR, "unable to bind socket: %s:%u: %s\n",
local_host, local_port, strerror(errno));
return -ENODEV;
}
}
/* figure out remote side of socket */
if (flags & OSMO_SOCK_F_CONNECT) {
result = addrinfo_helper(family, type, proto, remote_host, remote_port, false);
if (!result) {
close(sfd);
return -EINVAL;
}
for (rp = result; rp != NULL; rp = rp->ai_next) {
/* Workaround for glibc again */
if (type == SOCK_RAW) {
rp->ai_socktype = SOCK_RAW;
rp->ai_protocol = proto;
}
if (!sfd) {
sfd = socket_helper(rp, flags);
if (sfd < 0)
continue;
}
rc = connect(sfd, rp->ai_addr, rp->ai_addrlen);
if (rc != -1 || (rc == -1 && errno == EINPROGRESS))
break;
close(sfd);
sfd = -1;
}
freeaddrinfo(result);
if (rp == NULL) {
LOGP(DLGLOBAL, LOGL_ERROR, "unable to connect socket: %s:%u: %s\n",
remote_host, remote_port, strerror(errno));
return -ENODEV;
}
}
/* Make sure to call 'listen' on a bound, connection-oriented sock */
if ((flags & (OSMO_SOCK_F_BIND|OSMO_SOCK_F_CONNECT)) == OSMO_SOCK_F_BIND) {
switch (type) {
case SOCK_STREAM:
case SOCK_SEQPACKET:
listen(sfd, 10);
break;
}
}
return sfd;
}
/*! \brief Initialize a socket (including bind/connect)
* \param[in] family Address Family like AF_INET, AF_INET6, AF_UNSPEC
* \param[in] type Socket type like SOCK_DGRAM, SOCK_STREAM
@ -67,9 +249,8 @@
int osmo_sock_init(uint16_t family, uint16_t type, uint8_t proto,
const char *host, uint16_t port, unsigned int flags)
{
struct addrinfo hints, *result, *rp;
struct addrinfo *result, *rp;
int sfd, rc, on = 1;
char portbuf[16];
if ((flags & (OSMO_SOCK_F_BIND | OSMO_SOCK_F_CONNECT)) ==
(OSMO_SOCK_F_BIND | OSMO_SOCK_F_CONNECT)) {
@ -78,25 +259,8 @@ int osmo_sock_init(uint16_t family, uint16_t type, uint8_t proto,
return -EINVAL;
}
sprintf(portbuf, "%u", port);
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = family;
if (type == SOCK_RAW) {
/* Workaround for glibc, that returns EAI_SERVICE (-8) if
* SOCK_RAW and IPPROTO_GRE is used.
*/
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = IPPROTO_UDP;
} else {
hints.ai_socktype = type;
hints.ai_protocol = proto;
}
if (flags & OSMO_SOCK_F_BIND)
hints.ai_flags |= AI_PASSIVE;
rc = getaddrinfo(host, portbuf, &hints, &result);
if (rc != 0) {
result = addrinfo_helper(family, type, proto, host, port, flags & OSMO_SOCK_F_BIND);
if (!result) {
LOGP(DLGLOBAL, LOGL_ERROR, "getaddrinfo returned NULL: %s:%u: %s\n",
host, port, strerror(errno));
return -EINVAL;
@ -109,20 +273,10 @@ int osmo_sock_init(uint16_t family, uint16_t type, uint8_t proto,
rp->ai_protocol = proto;
}
sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
sfd = socket_helper(rp, flags);
if (sfd == -1)
continue;
if (flags & OSMO_SOCK_F_NONBLOCK) {
if (ioctl(sfd, FIONBIO, (unsigned char *)&on) < 0) {
LOGP(DLGLOBAL, LOGL_ERROR,
"cannot set this socket unblocking:"
" %s:%u: %s\n",
host, port, strerror(errno));
close(sfd);
freeaddrinfo(result);
return -EINVAL;
}
}
if (flags & OSMO_SOCK_F_CONNECT) {
rc = connect(sfd, rp->ai_addr, rp->ai_addrlen);
if (rc != -1 || (rc == -1 && errno == EINPROGRESS))

52
tests/socket/socket_test.c
View File

@ -73,6 +73,57 @@ static int test_sockinit(void)
return 0;
}
static int test_sockinit2(void)
{
int fd, rc;
char *name;
printf("Checking osmo_sock_init2() with bind to a random local UDP port\n");
fd = osmo_sock_init2(AF_INET, SOCK_DGRAM, IPPROTO_UDP,
"0.0.0.0", 0, NULL, 0, OSMO_SOCK_F_BIND);
OSMO_ASSERT(fd >= 0);
name = osmo_sock_get_name(NULL, fd);
/* expect it to be not connected. We cannot match on INADDR_ANY,
* as apparently that won't work on FreeBSD if there's only one
* address (e.g. 127.0.0.1) assigned to the entire system, like
* the Osmocom FreeBSD build slaves */
OSMO_ASSERT(!strncmp(name, "(NULL<->", 7));
talloc_free(name);
/* expect it to be blocking */
rc = fcntl(fd, F_GETFL);
OSMO_ASSERT(!(rc & O_NONBLOCK));
close(fd);
printf("Checking osmo_sock_init2() for OSMO_SOCK_F_NONBLOCK\n");
fd = osmo_sock_init2(AF_INET, SOCK_DGRAM, IPPROTO_UDP,
"0.0.0.0", 0, NULL, 0, OSMO_SOCK_F_BIND|OSMO_SOCK_F_NONBLOCK);
OSMO_ASSERT(fd >= 0);
/* expect it to be blocking */
rc = fcntl(fd, F_GETFL);
OSMO_ASSERT(rc & O_NONBLOCK);
close(fd);
printf("Checking osmo_sock_init2() for invalid flags\n");
fd = osmo_sock_init2(AF_INET, SOCK_DGRAM, IPPROTO_UDP, "0.0.0.0", 0, NULL, 0, 0);
OSMO_ASSERT(fd < 0);
printf("Checking osmo_sock_init2() for combined BIND + CONNECT\n");
fd = osmo_sock_init2(AF_INET, SOCK_DGRAM, IPPROTO_UDP, "127.0.0.1", 0, "127.0.0.1", 53,
OSMO_SOCK_F_BIND|OSMO_SOCK_F_CONNECT);
OSMO_ASSERT(fd >= 0);
name = osmo_sock_get_name(NULL, fd);
#ifndef __FreeBSD__
/* For some reason, on the jenkins.osmocom.org build slave with
* FreeBSD 10 inside a jail, it fails. Works fine on laforge's
* FreeBSD 10 or 11 VM at home */
OSMO_ASSERT(!strncmp(name, "(127.0.0.1:53<->127.0.0.1", 25));
#endif
talloc_free(name);
return 0;
}
const struct log_info_cat default_categories[] = {
};
@ -88,6 +139,7 @@ int main(int argc, char *argv[])
log_set_print_filename(osmo_stderr_target, 0);
test_sockinit();
test_sockinit2();
return EXIT_SUCCESS;
}

1
tests/socket/socket_test.err
View File

@ -1 +1,2 @@
invalid: both bind and connect flags set: 0.0.0.0:0
invalid: you have to specify either BIND or CONNECT flags

4
tests/socket/socket_test.ok
View File

@ -1,3 +1,7 @@
Checking osmo_sock_init() with bind to a random local UDP port
Checking for OSMO_SOCK_F_NONBLOCK
Checking for invalid flags
Checking osmo_sock_init2() with bind to a random local UDP port
Checking osmo_sock_init2() for OSMO_SOCK_F_NONBLOCK
Checking osmo_sock_init2() for invalid flags
Checking osmo_sock_init2() for combined BIND + CONNECT