nl80211: improve error handling

- introduce a new nl80211_request() which combines nl80211_msg() with
   nl80211_send() to simplify calling code

 - always invoke nl80211_free() in nl80211_send() and remove explicit
   nl80211_free() invocations in callers

 - back out early on netlink errors in functions performing multiple
   calls, e.g. when fetching scan results

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
This commit is contained in:
Jo-Philipp Wich 2017-06-26 09:20:24 +02:00
parent ab089dda34
commit 335967c6c2

View file

@ -374,7 +374,7 @@ static int nl80211_send(struct nl80211_msg_conveyor *cv,
void *cb_arg)
{
static struct nl80211_msg_conveyor rcv;
int err = 1;
int err;
if (cb_func)
nl_cb_set(cv->cb, NL_CB_VALID, NL_CB_CUSTOM, cb_func, cb_arg);
@ -386,6 +386,8 @@ static int nl80211_send(struct nl80211_msg_conveyor *cv,
if (err < 0)
goto out;
err = 1;
nl_cb_err(cv->cb, NL_CB_CUSTOM, nl80211_msg_error, &err);
nl_cb_set(cv->cb, NL_CB_FINISH, NL_CB_CUSTOM, nl80211_msg_finish, &err);
nl_cb_set(cv->cb, NL_CB_ACK, NL_CB_CUSTOM, nl80211_msg_ack, &err);
@ -394,9 +396,24 @@ static int nl80211_send(struct nl80211_msg_conveyor *cv,
nl_recvmsgs(nls->nl_sock, cv->cb);
out:
nl80211_free(cv);
return err;
}
static int nl80211_request(const char *ifname, int cmd, int flags,
int (*cb_func)(struct nl_msg *, void *),
void *cb_arg)
{
struct nl80211_msg_conveyor *cv;
cv = nl80211_msg(ifname, cmd, flags);
if (!cv)
return -ENOMEM;
return nl80211_send(cv, cb_func, cb_arg);
}
static struct nlattr ** nl80211_parse(struct nl_msg *msg)
{
struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
@ -443,18 +460,24 @@ static int nl80211_subscribe(const char *family, const char *group)
{
struct nl80211_group_conveyor cv = { .name = group, .id = -ENOENT };
struct nl80211_msg_conveyor *req;
int err;
req = nl80211_ctl(CTRL_CMD_GETFAMILY, 0);
if (req)
{
NLA_PUT_STRING(req->msg, CTRL_ATTR_FAMILY_NAME, family);
nl80211_send(req, nl80211_subscribe_cb, &cv);
err = nl80211_send(req, nl80211_subscribe_cb, &cv);
if (err)
return err;
return nl_socket_add_membership(nls->nl_sock, cv.id);
nla_put_failure:
nl80211_free(req);
}
return nl_socket_add_membership(nls->nl_sock, cv.id);
return -ENOMEM;
}
@ -550,16 +573,11 @@ static int nl80211_ifname2phy_cb(struct nl_msg *msg, void *arg)
static char * nl80211_ifname2phy(const char *ifname)
{
static char phy[32] = { 0 };
struct nl80211_msg_conveyor *req;
memset(phy, 0, sizeof(phy));
req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
if (req)
{
nl80211_send(req, nl80211_ifname2phy_cb, phy);
nl80211_free(req);
}
nl80211_request(ifname, NL80211_CMD_GET_WIPHY, 0,
nl80211_ifname2phy_cb, phy);
return phy[0] ? phy : NULL;
}
@ -642,17 +660,13 @@ static int nl80211_get_mode_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_mode(const char *ifname, int *buf)
{
char *res;
struct nl80211_msg_conveyor *req;
res = nl80211_phy2ifname(ifname);
req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_INTERFACE, 0);
*buf = IWINFO_OPMODE_UNKNOWN;
if (req)
{
nl80211_send(req, nl80211_get_mode_cb, buf);
nl80211_free(req);
}
res = nl80211_phy2ifname(ifname);
nl80211_request(res ? res : ifname, NL80211_CMD_GET_INTERFACE, 0,
nl80211_get_mode_cb, buf);
return (*buf == IWINFO_OPMODE_UNKNOWN) ? -1 : 0;
}
@ -892,7 +906,7 @@ static int __nl80211_wpactl_query(const char *ifname, ...)
static char * nl80211_ifadd(const char *ifname)
{
char *rv = NULL, path[PATH_MAX];
char path[PATH_MAX];
static char nif[IFNAMSIZ] = { 0 };
struct nl80211_msg_conveyor *req;
FILE *sysfs;
@ -916,18 +930,19 @@ static char * nl80211_ifadd(const char *ifname)
fclose(sysfs);
}
rv = nif;
return nif;
nla_put_failure:
nl80211_free(req);
}
return rv;
return NULL;
}
static void nl80211_ifdel(const char *ifname)
{
struct nl80211_msg_conveyor *req;
int err;
req = nl80211_msg(ifname, NL80211_CMD_DEL_INTERFACE, 0);
if (req)
@ -935,6 +950,7 @@ static void nl80211_ifdel(const char *ifname)
NLA_PUT_STRING(req->msg, NL80211_ATTR_IFNAME, ifname);
nl80211_send(req, NULL, NULL);
return;
nla_put_failure:
nl80211_free(req);
@ -1035,47 +1051,33 @@ static int nl80211_get_ssid_bssid_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_ssid(const char *ifname, char *buf)
{
char *res;
struct nl80211_msg_conveyor *req;
struct nl80211_ssid_bssid sb;
struct nl80211_ssid_bssid sb = { .ssid = (unsigned char *)buf };
/* try to find ssid from scan dump results */
res = nl80211_phy2ifname(ifname);
req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP);
sb.ssid[0] = 0;
sb.ssid = (unsigned char *)buf;
*buf = 0;
if (req)
{
nl80211_send(req, nl80211_get_ssid_bssid_cb, &sb);
nl80211_free(req);
}
nl80211_request(res ? res : ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP,
nl80211_get_ssid_bssid_cb, &sb);
/* failed, try to find from hostapd info */
if (*buf == 0)
nl80211_hostapd_query(ifname, "ssid", buf, IWINFO_ESSID_MAX_SIZE + 1);
if (sb.ssid[0] == 0)
nl80211_hostapd_query(ifname, "ssid", sb.ssid,
IWINFO_ESSID_MAX_SIZE + 1);
return (*buf == 0) ? -1 : 0;
return (sb.ssid[0] == 0) ? -1 : 0;
}
static int nl80211_get_bssid(const char *ifname, char *buf)
{
char *res, bssid[sizeof("FF:FF:FF:FF:FF:FF\0")];
struct nl80211_msg_conveyor *req;
struct nl80211_ssid_bssid sb;
struct nl80211_ssid_bssid sb = { };
/* try to find bssid from scan dump results */
res = nl80211_phy2ifname(ifname);
req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP);
sb.ssid = NULL;
sb.bssid[0] = 0;
if (req)
{
nl80211_send(req, nl80211_get_ssid_bssid_cb, &sb);
nl80211_free(req);
}
nl80211_request(res ? res : ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP,
nl80211_get_ssid_bssid_cb, &sb);
/* failed, try to find mac from hostapd info */
if ((sb.bssid[0] == 0) &&
@ -1139,18 +1141,13 @@ static int nl80211_get_frequency_info_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_frequency(const char *ifname, int *buf)
{
char *res, channel[4], hwmode[2];
struct nl80211_msg_conveyor *req;
/* try to find frequency from interface info */
res = nl80211_phy2ifname(ifname);
req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_INTERFACE, 0);
*buf = 0;
if (req)
{
nl80211_send(req, nl80211_get_frequency_info_cb, buf);
nl80211_free(req);
}
nl80211_request(res ? res : ifname, NL80211_CMD_GET_INTERFACE, 0,
nl80211_get_frequency_info_cb, buf);
/* failed, try to find frequency from hostapd info */
if ((*buf == 0) &&
@ -1164,13 +1161,9 @@ static int nl80211_get_frequency(const char *ifname, int *buf)
if (*buf == 0)
{
res = nl80211_phy2ifname(ifname);
req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP);
if (req)
{
nl80211_send(req, nl80211_get_frequency_scan_cb, buf);
nl80211_free(req);
}
nl80211_request(res ? res : ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP,
nl80211_get_frequency_scan_cb, buf);
}
return (*buf == 0) ? -1 : 0;
@ -1201,21 +1194,15 @@ static int nl80211_get_txpower_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_txpower(const char *ifname, int *buf)
{
char *res;
struct nl80211_msg_conveyor *req;
res = nl80211_phy2ifname(ifname);
req = nl80211_msg(res ? res : ifname, NL80211_CMD_GET_INTERFACE, 0);
if (req)
{
*buf = 0;
nl80211_send(req, nl80211_get_txpower_cb, buf);
nl80211_free(req);
if (*buf)
return 0;
}
if (nl80211_request(res ? res : ifname, NL80211_CMD_GET_INTERFACE, 0,
nl80211_get_txpower_cb, buf))
return -1;
return 0;
}
@ -1283,7 +1270,6 @@ static void nl80211_fill_signal(const char *ifname, struct nl80211_rssi_rate *r)
{
DIR *d;
struct dirent *de;
struct nl80211_msg_conveyor *req;
r->rssi = 0;
r->rate = 0;
@ -1296,14 +1282,8 @@ static void nl80211_fill_signal(const char *ifname, struct nl80211_rssi_rate *r)
(!de->d_name[strlen(ifname)] ||
!strncmp(&de->d_name[strlen(ifname)], ".sta", 4)))
{
req = nl80211_msg(de->d_name, NL80211_CMD_GET_STATION,
NLM_F_DUMP);
if (req)
{
nl80211_send(req, nl80211_fill_signal_cb, r);
nl80211_free(req);
}
nl80211_request(de->d_name, NL80211_CMD_GET_STATION,
NLM_F_DUMP, nl80211_fill_signal_cb, r);
}
}
@ -1371,24 +1351,17 @@ static int nl80211_get_noise_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_noise(const char *ifname, int *buf)
{
int8_t noise;
struct nl80211_msg_conveyor *req;
int8_t noise = 0;
req = nl80211_msg(ifname, NL80211_CMD_GET_SURVEY, NLM_F_DUMP);
if (req)
{
noise = 0;
if (nl80211_request(ifname, NL80211_CMD_GET_SURVEY, NLM_F_DUMP,
nl80211_get_noise_cb, &noise))
goto out;
nl80211_send(req, nl80211_get_noise_cb, &noise);
nl80211_free(req);
if (noise)
{
*buf = noise;
return 0;
}
}
out:
*buf = 0;
return -1;
}
@ -1792,7 +1765,6 @@ static int nl80211_get_assoclist(const char *ifname, char *buf, int *len)
DIR *d;
int i, noise = 0;
struct dirent *de;
struct nl80211_msg_conveyor *req;
struct nl80211_array_buf arr = { .buf = buf, .count = 0 };
struct iwinfo_assoclist_entry *e;
@ -1804,14 +1776,8 @@ static int nl80211_get_assoclist(const char *ifname, char *buf, int *len)
(!de->d_name[strlen(ifname)] ||
!strncmp(&de->d_name[strlen(ifname)], ".sta", 4)))
{
req = nl80211_msg(de->d_name, NL80211_CMD_GET_STATION,
NLM_F_DUMP);
if (req)
{
nl80211_send(req, nl80211_get_assoclist_cb, &arr);
nl80211_free(req);
}
nl80211_request(de->d_name, NL80211_CMD_GET_STATION,
NLM_F_DUMP, nl80211_get_assoclist_cb, &arr);
}
}
@ -1879,7 +1845,7 @@ static int nl80211_get_txpwrlist_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_txpwrlist(const char *ifname, char *buf, int *len)
{
int ch_cur;
int err, ch_cur;
int dbm_max = -1, dbm_cur, dbm_cnt;
struct nl80211_msg_conveyor *req;
struct iwinfo_txpwrlist_entry entry;
@ -1887,17 +1853,13 @@ static int nl80211_get_txpwrlist(const char *ifname, char *buf, int *len)
if (nl80211_get_channel(ifname, &ch_cur))
ch_cur = 0;
req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
if (req)
{
/* initialize the value pointer with channel for callback */
dbm_max = ch_cur;
nl80211_send(req, nl80211_get_txpwrlist_cb, &dbm_max);
nl80211_free(req);
}
err = nl80211_request(ifname, NL80211_CMD_GET_WIPHY, 0,
nl80211_get_txpwrlist_cb, &dbm_max);
if (dbm_max > 0)
if (!err)
{
for (dbm_cur = 0, dbm_cnt = 0;
dbm_cur < dbm_max;
@ -2100,27 +2062,24 @@ static int nl80211_get_scanlist_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_scanlist_nl(const char *ifname, char *buf, int *len)
{
struct nl80211_msg_conveyor *req;
struct nl80211_scanlist sl = { .e = (struct iwinfo_scanlist_entry *)buf };
req = nl80211_msg(ifname, NL80211_CMD_TRIGGER_SCAN, 0);
if (req)
{
nl80211_send(req, NULL, NULL);
nl80211_free(req);
}
if (nl80211_request(ifname, NL80211_CMD_TRIGGER_SCAN, 0, NULL, NULL))
goto out;
nl80211_wait("nl80211", "scan", NL80211_CMD_NEW_SCAN_RESULTS);
if (nl80211_wait("nl80211", "scan", NL80211_CMD_NEW_SCAN_RESULTS))
goto out;
req = nl80211_msg(ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP);
if (req)
{
nl80211_send(req, nl80211_get_scanlist_cb, &sl);
nl80211_free(req);
}
if (nl80211_request(ifname, NL80211_CMD_GET_SCAN, NLM_F_DUMP,
nl80211_get_scanlist_cb, &sl))
goto out;
*len = sl.len * sizeof(struct iwinfo_scanlist_entry);
return *len ? 0 : -1;
return 0;
out:
*len = 0;
return -1;
}
static int wpasupp_ssid_decode(const char *in, char *out, int outlen)
@ -2447,22 +2406,17 @@ static int nl80211_get_freqlist_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_freqlist(const char *ifname, char *buf, int *len)
{
struct nl80211_msg_conveyor *req;
struct nl80211_array_buf arr = { .buf = buf, .count = 0 };
req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
if (req)
{
nl80211_send(req, nl80211_get_freqlist_cb, &arr);
nl80211_free(req);
}
if (nl80211_request(ifname, NL80211_CMD_GET_WIPHY, 0,
nl80211_get_freqlist_cb, &arr))
goto out;
if (arr.count > 0)
{
*len = arr.count * sizeof(struct iwinfo_freqlist_entry);
return 0;
}
out:
*len = 0;
return -1;
}
@ -2481,20 +2435,11 @@ static int nl80211_get_country_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_country(const char *ifname, char *buf)
{
int rv = -1;
struct nl80211_msg_conveyor *req;
if (nl80211_request(ifname, NL80211_CMD_GET_REG, 0,
nl80211_get_country_cb, buf))
return -1;
req = nl80211_msg(ifname, NL80211_CMD_GET_REG, 0);
if (req)
{
nl80211_send(req, nl80211_get_country_cb, buf);
nl80211_free(req);
if (buf[0])
rv = 0;
}
return rv;
return 0;
}
static int nl80211_get_countrylist(const char *ifname, char *buf, int *len)
@ -2604,43 +2549,39 @@ static int nl80211_get_modelist_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_hwmodelist(const char *ifname, int *buf)
{
struct nl80211_msg_conveyor *req;
struct nl80211_modes m = { 0 };
req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
if (req)
{
nl80211_send(req, nl80211_get_modelist_cb, &m);
nl80211_free(req);
}
if (nl80211_request(ifname, NL80211_CMD_GET_WIPHY, 0,
nl80211_get_modelist_cb, &m))
goto out;
if (!m.ok)
goto out;
if (m.ok)
{
*buf = m.hw;
return 0;
}
out:
*buf = 0;
return -1;
}
static int nl80211_get_htmodelist(const char *ifname, int *buf)
{
struct nl80211_msg_conveyor *req;
struct nl80211_modes m = { 0 };
req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
if (req)
{
nl80211_send(req, nl80211_get_modelist_cb, &m);
nl80211_free(req);
}
if (nl80211_request(ifname, NL80211_CMD_GET_WIPHY, 0,
nl80211_get_modelist_cb, &m))
goto out;
if (!m.ok)
goto out;
if (m.ok)
{
*buf = m.ht;
return 0;
}
out:
*buf = 0;
return -1;
}
@ -2700,14 +2641,10 @@ static int nl80211_get_ifcomb_cb(struct nl_msg *msg, void *arg)
static int nl80211_get_mbssid_support(const char *ifname, int *buf)
{
struct nl80211_msg_conveyor *req;
req = nl80211_msg(ifname, NL80211_CMD_GET_WIPHY, 0);
if (!req)
if (nl80211_request(ifname, NL80211_CMD_GET_WIPHY, 0,
nl80211_get_ifcomb_cb, buf))
return -1;
nl80211_send(req, nl80211_get_ifcomb_cb, buf);
nl80211_free(req);
return 0;
}