hostap/wpa_supplicant/ctrl_iface_unix.c
Ben Greear 4fdc8def88 Make UNIX socket non-blocking for ctrl_iface
This keeps wpa_cli from hanging forever if the other end of the socket
dies.

Signed-hostap: Ben Greear <greearb@candelatech.com>
2012-08-04 20:34:27 +03:00

746 lines
18 KiB
C

/*
* WPA Supplicant / UNIX domain socket -based control interface
* Copyright (c) 2004-2009, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include <sys/un.h>
#include <sys/stat.h>
#include <grp.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#ifdef ANDROID
#include <cutils/sockets.h>
#endif /* ANDROID */
#include "utils/common.h"
#include "utils/eloop.h"
#include "utils/list.h"
#include "eapol_supp/eapol_supp_sm.h"
#include "config.h"
#include "wpa_supplicant_i.h"
#include "ctrl_iface.h"
/* Per-interface ctrl_iface */
/**
* struct wpa_ctrl_dst - Internal data structure of control interface monitors
*
* This structure is used to store information about registered control
* interface monitors into struct wpa_supplicant. This data is private to
* ctrl_iface_unix.c and should not be touched directly from other files.
*/
struct wpa_ctrl_dst {
struct dl_list list;
struct sockaddr_un addr;
socklen_t addrlen;
int debug_level;
int errors;
};
struct ctrl_iface_priv {
struct wpa_supplicant *wpa_s;
int sock;
struct dl_list ctrl_dst;
};
static void wpa_supplicant_ctrl_iface_send(struct ctrl_iface_priv *priv,
int level, const char *buf,
size_t len);
static int wpa_supplicant_ctrl_iface_attach(struct ctrl_iface_priv *priv,
struct sockaddr_un *from,
socklen_t fromlen)
{
struct wpa_ctrl_dst *dst;
dst = os_zalloc(sizeof(*dst));
if (dst == NULL)
return -1;
os_memcpy(&dst->addr, from, sizeof(struct sockaddr_un));
dst->addrlen = fromlen;
dst->debug_level = MSG_INFO;
dl_list_add(&priv->ctrl_dst, &dst->list);
wpa_hexdump(MSG_DEBUG, "CTRL_IFACE monitor attached",
(u8 *) from->sun_path,
fromlen - offsetof(struct sockaddr_un, sun_path));
return 0;
}
static int wpa_supplicant_ctrl_iface_detach(struct ctrl_iface_priv *priv,
struct sockaddr_un *from,
socklen_t fromlen)
{
struct wpa_ctrl_dst *dst;
dl_list_for_each(dst, &priv->ctrl_dst, struct wpa_ctrl_dst, list) {
if (fromlen == dst->addrlen &&
os_memcmp(from->sun_path, dst->addr.sun_path,
fromlen - offsetof(struct sockaddr_un, sun_path))
== 0) {
dl_list_del(&dst->list);
os_free(dst);
wpa_hexdump(MSG_DEBUG, "CTRL_IFACE monitor detached",
(u8 *) from->sun_path,
fromlen -
offsetof(struct sockaddr_un, sun_path));
return 0;
}
}
return -1;
}
static int wpa_supplicant_ctrl_iface_level(struct ctrl_iface_priv *priv,
struct sockaddr_un *from,
socklen_t fromlen,
char *level)
{
struct wpa_ctrl_dst *dst;
wpa_printf(MSG_DEBUG, "CTRL_IFACE LEVEL %s", level);
dl_list_for_each(dst, &priv->ctrl_dst, struct wpa_ctrl_dst, list) {
if (fromlen == dst->addrlen &&
os_memcmp(from->sun_path, dst->addr.sun_path,
fromlen - offsetof(struct sockaddr_un, sun_path))
== 0) {
wpa_hexdump(MSG_DEBUG, "CTRL_IFACE changed monitor "
"level", (u8 *) from->sun_path,
fromlen -
offsetof(struct sockaddr_un, sun_path));
dst->debug_level = atoi(level);
return 0;
}
}
return -1;
}
static void wpa_supplicant_ctrl_iface_receive(int sock, void *eloop_ctx,
void *sock_ctx)
{
struct wpa_supplicant *wpa_s = eloop_ctx;
struct ctrl_iface_priv *priv = sock_ctx;
char buf[4096];
int res;
struct sockaddr_un from;
socklen_t fromlen = sizeof(from);
char *reply = NULL;
size_t reply_len = 0;
int new_attached = 0;
res = recvfrom(sock, buf, sizeof(buf) - 1, 0,
(struct sockaddr *) &from, &fromlen);
if (res < 0) {
perror("recvfrom(ctrl_iface)");
return;
}
buf[res] = '\0';
if (os_strcmp(buf, "ATTACH") == 0) {
if (wpa_supplicant_ctrl_iface_attach(priv, &from, fromlen))
reply_len = 1;
else {
new_attached = 1;
reply_len = 2;
}
} else if (os_strcmp(buf, "DETACH") == 0) {
if (wpa_supplicant_ctrl_iface_detach(priv, &from, fromlen))
reply_len = 1;
else
reply_len = 2;
} else if (os_strncmp(buf, "LEVEL ", 6) == 0) {
if (wpa_supplicant_ctrl_iface_level(priv, &from, fromlen,
buf + 6))
reply_len = 1;
else
reply_len = 2;
} else {
reply = wpa_supplicant_ctrl_iface_process(wpa_s, buf,
&reply_len);
}
if (reply) {
sendto(sock, reply, reply_len, 0, (struct sockaddr *) &from,
fromlen);
os_free(reply);
} else if (reply_len == 1) {
sendto(sock, "FAIL\n", 5, 0, (struct sockaddr *) &from,
fromlen);
} else if (reply_len == 2) {
sendto(sock, "OK\n", 3, 0, (struct sockaddr *) &from,
fromlen);
}
if (new_attached)
eapol_sm_notify_ctrl_attached(wpa_s->eapol);
}
static char * wpa_supplicant_ctrl_iface_path(struct wpa_supplicant *wpa_s)
{
char *buf;
size_t len;
char *pbuf, *dir = NULL, *gid_str = NULL;
int res;
if (wpa_s->conf->ctrl_interface == NULL)
return NULL;
pbuf = os_strdup(wpa_s->conf->ctrl_interface);
if (pbuf == NULL)
return NULL;
if (os_strncmp(pbuf, "DIR=", 4) == 0) {
dir = pbuf + 4;
gid_str = os_strstr(dir, " GROUP=");
if (gid_str) {
*gid_str = '\0';
gid_str += 7;
}
} else
dir = pbuf;
len = os_strlen(dir) + os_strlen(wpa_s->ifname) + 2;
buf = os_malloc(len);
if (buf == NULL) {
os_free(pbuf);
return NULL;
}
res = os_snprintf(buf, len, "%s/%s", dir, wpa_s->ifname);
if (res < 0 || (size_t) res >= len) {
os_free(pbuf);
os_free(buf);
return NULL;
}
#ifdef __CYGWIN__
{
/* Windows/WinPcap uses interface names that are not suitable
* as a file name - convert invalid chars to underscores */
char *pos = buf;
while (*pos) {
if (*pos == '\\')
*pos = '_';
pos++;
}
}
#endif /* __CYGWIN__ */
os_free(pbuf);
return buf;
}
static void wpa_supplicant_ctrl_iface_msg_cb(void *ctx, int level,
const char *txt, size_t len)
{
struct wpa_supplicant *wpa_s = ctx;
if (wpa_s == NULL || wpa_s->ctrl_iface == NULL)
return;
wpa_supplicant_ctrl_iface_send(wpa_s->ctrl_iface, level, txt, len);
}
struct ctrl_iface_priv *
wpa_supplicant_ctrl_iface_init(struct wpa_supplicant *wpa_s)
{
struct ctrl_iface_priv *priv;
struct sockaddr_un addr;
char *fname = NULL;
gid_t gid = 0;
int gid_set = 0;
char *buf, *dir = NULL, *gid_str = NULL;
struct group *grp;
char *endp;
int flags;
priv = os_zalloc(sizeof(*priv));
if (priv == NULL)
return NULL;
dl_list_init(&priv->ctrl_dst);
priv->wpa_s = wpa_s;
priv->sock = -1;
if (wpa_s->conf->ctrl_interface == NULL)
return priv;
buf = os_strdup(wpa_s->conf->ctrl_interface);
if (buf == NULL)
goto fail;
#ifdef ANDROID
os_snprintf(addr.sun_path, sizeof(addr.sun_path), "wpa_%s",
wpa_s->conf->ctrl_interface);
priv->sock = android_get_control_socket(addr.sun_path);
if (priv->sock >= 0)
goto havesock;
#endif /* ANDROID */
if (os_strncmp(buf, "DIR=", 4) == 0) {
dir = buf + 4;
gid_str = os_strstr(dir, " GROUP=");
if (gid_str) {
*gid_str = '\0';
gid_str += 7;
}
} else {
dir = buf;
gid_str = wpa_s->conf->ctrl_interface_group;
}
if (mkdir(dir, S_IRWXU | S_IRWXG) < 0) {
if (errno == EEXIST) {
wpa_printf(MSG_DEBUG, "Using existing control "
"interface directory.");
} else {
perror("mkdir[ctrl_interface]");
goto fail;
}
}
if (gid_str) {
grp = getgrnam(gid_str);
if (grp) {
gid = grp->gr_gid;
gid_set = 1;
wpa_printf(MSG_DEBUG, "ctrl_interface_group=%d"
" (from group name '%s')",
(int) gid, gid_str);
} else {
/* Group name not found - try to parse this as gid */
gid = strtol(gid_str, &endp, 10);
if (*gid_str == '\0' || *endp != '\0') {
wpa_printf(MSG_ERROR, "CTRL: Invalid group "
"'%s'", gid_str);
goto fail;
}
gid_set = 1;
wpa_printf(MSG_DEBUG, "ctrl_interface_group=%d",
(int) gid);
}
}
if (gid_set && chown(dir, -1, gid) < 0) {
perror("chown[ctrl_interface]");
goto fail;
}
/* Make sure the group can enter and read the directory */
if (gid_set &&
chmod(dir, S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP) < 0) {
wpa_printf(MSG_ERROR, "CTRL: chmod[ctrl_interface]: %s",
strerror(errno));
goto fail;
}
if (os_strlen(dir) + 1 + os_strlen(wpa_s->ifname) >=
sizeof(addr.sun_path)) {
wpa_printf(MSG_ERROR, "ctrl_iface path limit exceeded");
goto fail;
}
priv->sock = socket(PF_UNIX, SOCK_DGRAM, 0);
if (priv->sock < 0) {
perror("socket(PF_UNIX)");
goto fail;
}
os_memset(&addr, 0, sizeof(addr));
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
addr.sun_len = sizeof(addr);
#endif /* __FreeBSD__ */
addr.sun_family = AF_UNIX;
fname = wpa_supplicant_ctrl_iface_path(wpa_s);
if (fname == NULL)
goto fail;
os_strlcpy(addr.sun_path, fname, sizeof(addr.sun_path));
if (bind(priv->sock, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
wpa_printf(MSG_DEBUG, "ctrl_iface bind(PF_UNIX) failed: %s",
strerror(errno));
if (connect(priv->sock, (struct sockaddr *) &addr,
sizeof(addr)) < 0) {
wpa_printf(MSG_DEBUG, "ctrl_iface exists, but does not"
" allow connections - assuming it was left"
"over from forced program termination");
if (unlink(fname) < 0) {
perror("unlink[ctrl_iface]");
wpa_printf(MSG_ERROR, "Could not unlink "
"existing ctrl_iface socket '%s'",
fname);
goto fail;
}
if (bind(priv->sock, (struct sockaddr *) &addr,
sizeof(addr)) < 0) {
perror("supp-ctrl-iface-init: bind(PF_UNIX)");
goto fail;
}
wpa_printf(MSG_DEBUG, "Successfully replaced leftover "
"ctrl_iface socket '%s'", fname);
} else {
wpa_printf(MSG_INFO, "ctrl_iface exists and seems to "
"be in use - cannot override it");
wpa_printf(MSG_INFO, "Delete '%s' manually if it is "
"not used anymore", fname);
os_free(fname);
fname = NULL;
goto fail;
}
}
if (gid_set && chown(fname, -1, gid) < 0) {
perror("chown[ctrl_interface/ifname]");
goto fail;
}
if (chmod(fname, S_IRWXU | S_IRWXG) < 0) {
perror("chmod[ctrl_interface/ifname]");
goto fail;
}
os_free(fname);
#ifdef ANDROID
havesock:
#endif /* ANDROID */
/*
* Make socket non-blocking so that we don't hang forever if
* target dies unexpectedly.
*/
flags = fcntl(priv->sock, F_GETFL);
if (flags >= 0) {
flags |= O_NONBLOCK;
if (fcntl(priv->sock, F_SETFL, flags) < 0) {
perror("fcntl(ctrl, O_NONBLOCK)");
/* Not fatal, continue on.*/
}
}
eloop_register_read_sock(priv->sock, wpa_supplicant_ctrl_iface_receive,
wpa_s, priv);
wpa_msg_register_cb(wpa_supplicant_ctrl_iface_msg_cb);
os_free(buf);
return priv;
fail:
if (priv->sock >= 0)
close(priv->sock);
os_free(priv);
if (fname) {
unlink(fname);
os_free(fname);
}
os_free(buf);
return NULL;
}
void wpa_supplicant_ctrl_iface_deinit(struct ctrl_iface_priv *priv)
{
struct wpa_ctrl_dst *dst, *prev;
if (priv->sock > -1) {
char *fname;
char *buf, *dir = NULL, *gid_str = NULL;
eloop_unregister_read_sock(priv->sock);
if (!dl_list_empty(&priv->ctrl_dst)) {
/*
* Wait a second before closing the control socket if
* there are any attached monitors in order to allow
* them to receive any pending messages.
*/
wpa_printf(MSG_DEBUG, "CTRL_IFACE wait for attached "
"monitors to receive messages");
os_sleep(1, 0);
}
close(priv->sock);
priv->sock = -1;
fname = wpa_supplicant_ctrl_iface_path(priv->wpa_s);
if (fname) {
unlink(fname);
os_free(fname);
}
buf = os_strdup(priv->wpa_s->conf->ctrl_interface);
if (buf == NULL)
goto free_dst;
if (os_strncmp(buf, "DIR=", 4) == 0) {
dir = buf + 4;
gid_str = os_strstr(dir, " GROUP=");
if (gid_str) {
*gid_str = '\0';
gid_str += 7;
}
} else
dir = buf;
if (rmdir(dir) < 0) {
if (errno == ENOTEMPTY) {
wpa_printf(MSG_DEBUG, "Control interface "
"directory not empty - leaving it "
"behind");
} else {
perror("rmdir[ctrl_interface]");
}
}
os_free(buf);
}
free_dst:
dl_list_for_each_safe(dst, prev, &priv->ctrl_dst, struct wpa_ctrl_dst,
list)
os_free(dst);
os_free(priv);
}
/**
* wpa_supplicant_ctrl_iface_send - Send a control interface packet to monitors
* @priv: Pointer to private data from wpa_supplicant_ctrl_iface_init()
* @level: Priority level of the message
* @buf: Message data
* @len: Message length
*
* Send a packet to all monitor programs attached to the control interface.
*/
static void wpa_supplicant_ctrl_iface_send(struct ctrl_iface_priv *priv,
int level, const char *buf,
size_t len)
{
struct wpa_ctrl_dst *dst, *next;
char levelstr[10];
int idx, res;
struct msghdr msg;
struct iovec io[2];
if (priv->sock < 0 || dl_list_empty(&priv->ctrl_dst))
return;
res = os_snprintf(levelstr, sizeof(levelstr), "<%d>", level);
if (res < 0 || (size_t) res >= sizeof(levelstr))
return;
io[0].iov_base = levelstr;
io[0].iov_len = os_strlen(levelstr);
io[1].iov_base = (char *) buf;
io[1].iov_len = len;
os_memset(&msg, 0, sizeof(msg));
msg.msg_iov = io;
msg.msg_iovlen = 2;
idx = 0;
dl_list_for_each_safe(dst, next, &priv->ctrl_dst, struct wpa_ctrl_dst,
list) {
if (level >= dst->debug_level) {
wpa_hexdump(MSG_DEBUG, "CTRL_IFACE monitor send",
(u8 *) dst->addr.sun_path, dst->addrlen -
offsetof(struct sockaddr_un, sun_path));
msg.msg_name = (void *) &dst->addr;
msg.msg_namelen = dst->addrlen;
if (sendmsg(priv->sock, &msg, 0) < 0) {
int _errno = errno;
wpa_printf(MSG_INFO, "CTRL_IFACE monitor[%d]: "
"%d - %s",
idx, errno, strerror(errno));
dst->errors++;
if (dst->errors > 1000 ||
(_errno != ENOBUFS && dst->errors > 10) ||
_errno == ENOENT) {
wpa_supplicant_ctrl_iface_detach(
priv, &dst->addr,
dst->addrlen);
}
} else
dst->errors = 0;
}
idx++;
}
}
void wpa_supplicant_ctrl_iface_wait(struct ctrl_iface_priv *priv)
{
char buf[256];
int res;
struct sockaddr_un from;
socklen_t fromlen = sizeof(from);
for (;;) {
wpa_printf(MSG_DEBUG, "CTRL_IFACE - %s - wait for monitor to "
"attach", priv->wpa_s->ifname);
eloop_wait_for_read_sock(priv->sock);
res = recvfrom(priv->sock, buf, sizeof(buf) - 1, 0,
(struct sockaddr *) &from, &fromlen);
if (res < 0) {
perror("recvfrom(ctrl_iface)");
continue;
}
buf[res] = '\0';
if (os_strcmp(buf, "ATTACH") == 0) {
/* handle ATTACH signal of first monitor interface */
if (!wpa_supplicant_ctrl_iface_attach(priv, &from,
fromlen)) {
sendto(priv->sock, "OK\n", 3, 0,
(struct sockaddr *) &from, fromlen);
/* OK to continue */
return;
} else {
sendto(priv->sock, "FAIL\n", 5, 0,
(struct sockaddr *) &from, fromlen);
}
} else {
/* return FAIL for all other signals */
sendto(priv->sock, "FAIL\n", 5, 0,
(struct sockaddr *) &from, fromlen);
}
}
}
/* Global ctrl_iface */
struct ctrl_iface_global_priv {
struct wpa_global *global;
int sock;
};
static void wpa_supplicant_global_ctrl_iface_receive(int sock, void *eloop_ctx,
void *sock_ctx)
{
struct wpa_global *global = eloop_ctx;
char buf[256];
int res;
struct sockaddr_un from;
socklen_t fromlen = sizeof(from);
char *reply;
size_t reply_len;
res = recvfrom(sock, buf, sizeof(buf) - 1, 0,
(struct sockaddr *) &from, &fromlen);
if (res < 0) {
perror("recvfrom(ctrl_iface)");
return;
}
buf[res] = '\0';
reply = wpa_supplicant_global_ctrl_iface_process(global, buf,
&reply_len);
if (reply) {
sendto(sock, reply, reply_len, 0, (struct sockaddr *) &from,
fromlen);
os_free(reply);
} else if (reply_len) {
sendto(sock, "FAIL\n", 5, 0, (struct sockaddr *) &from,
fromlen);
}
}
struct ctrl_iface_global_priv *
wpa_supplicant_global_ctrl_iface_init(struct wpa_global *global)
{
struct ctrl_iface_global_priv *priv;
struct sockaddr_un addr;
priv = os_zalloc(sizeof(*priv));
if (priv == NULL)
return NULL;
priv->global = global;
priv->sock = -1;
if (global->params.ctrl_interface == NULL)
return priv;
#ifdef ANDROID
priv->sock = android_get_control_socket(global->params.ctrl_interface);
if (priv->sock >= 0)
goto havesock;
#endif /* ANDROID */
wpa_printf(MSG_DEBUG, "Global control interface '%s'",
global->params.ctrl_interface);
priv->sock = socket(PF_UNIX, SOCK_DGRAM, 0);
if (priv->sock < 0) {
perror("socket(PF_UNIX)");
goto fail;
}
os_memset(&addr, 0, sizeof(addr));
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
addr.sun_len = sizeof(addr);
#endif /* __FreeBSD__ */
addr.sun_family = AF_UNIX;
os_strlcpy(addr.sun_path, global->params.ctrl_interface,
sizeof(addr.sun_path));
if (bind(priv->sock, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
perror("supp-global-ctrl-iface-init (will try fixup): "
"bind(PF_UNIX)");
if (connect(priv->sock, (struct sockaddr *) &addr,
sizeof(addr)) < 0) {
wpa_printf(MSG_DEBUG, "ctrl_iface exists, but does not"
" allow connections - assuming it was left"
"over from forced program termination");
if (unlink(global->params.ctrl_interface) < 0) {
perror("unlink[ctrl_iface]");
wpa_printf(MSG_ERROR, "Could not unlink "
"existing ctrl_iface socket '%s'",
global->params.ctrl_interface);
goto fail;
}
if (bind(priv->sock, (struct sockaddr *) &addr,
sizeof(addr)) < 0) {
perror("supp-glb-iface-init: bind(PF_UNIX)");
goto fail;
}
wpa_printf(MSG_DEBUG, "Successfully replaced leftover "
"ctrl_iface socket '%s'",
global->params.ctrl_interface);
} else {
wpa_printf(MSG_INFO, "ctrl_iface exists and seems to "
"be in use - cannot override it");
wpa_printf(MSG_INFO, "Delete '%s' manually if it is "
"not used anymore",
global->params.ctrl_interface);
goto fail;
}
}
#ifdef ANDROID
havesock:
#endif /* ANDROID */
eloop_register_read_sock(priv->sock,
wpa_supplicant_global_ctrl_iface_receive,
global, NULL);
return priv;
fail:
if (priv->sock >= 0)
close(priv->sock);
os_free(priv);
return NULL;
}
void
wpa_supplicant_global_ctrl_iface_deinit(struct ctrl_iface_global_priv *priv)
{
if (priv->sock >= 0) {
eloop_unregister_read_sock(priv->sock);
close(priv->sock);
}
if (priv->global->params.ctrl_interface)
unlink(priv->global->params.ctrl_interface);
os_free(priv);
}