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Fix hostapd config file reloading with BSS addition/removal

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BSS additional/removal cases were not considered at all in the previous
implementation of hostapd configuration file reloading on SIGHUP. Such
changes resulted in num_bss values getting out of sync in runtime data
and configuration data and likely dereferencing of freed memory (e.g.,
when removing a BSS).

Fix this by forcing a full disable/enable sequence for the interface if
any BSS entry is added/removed or if an interface name changes between
the old and the new configuration.

Signed-off-by: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2018-11-26 00:51:38 +02:00
parent cabbaac119
commit 6e7b4c45fa
1 changed files with 48 additions and 0 deletions
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48
src/ap/hostapd.c
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@ -176,8 +176,27 @@ static void hostapd_clear_old(struct hostapd_iface *iface)
} }
static int hostapd_iface_conf_changed(struct hostapd_config *newconf,
struct hostapd_config *oldconf)
{
size_t i;
if (newconf->num_bss != oldconf->num_bss)
return 1;
for (i = 0; i < newconf->num_bss; i++) {
if (os_strcmp(newconf->bss[i]->iface,
oldconf->bss[i]->iface) != 0)
return 1;
}
return 0;
}
int hostapd_reload_config(struct hostapd_iface *iface) int hostapd_reload_config(struct hostapd_iface *iface)
{ {
struct hapd_interfaces *interfaces = iface->interfaces;
struct hostapd_data *hapd = iface->bss[0]; struct hostapd_data *hapd = iface->bss[0];
struct hostapd_config *newconf, *oldconf; struct hostapd_config *newconf, *oldconf;
size_t j; size_t j;
@ -200,6 +219,35 @@ int hostapd_reload_config(struct hostapd_iface *iface)
hostapd_clear_old(iface); hostapd_clear_old(iface);
oldconf = hapd->iconf; oldconf = hapd->iconf;
if (hostapd_iface_conf_changed(newconf, oldconf)) {
char *fname;
int res;
wpa_printf(MSG_DEBUG,
"Configuration changes include interface/BSS modification - force full disable+enable sequence");
fname = os_strdup(iface->config_fname);
if (!fname) {
hostapd_config_free(newconf);
return -1;
}
hostapd_remove_iface(interfaces, hapd->conf->iface);
iface = hostapd_init(interfaces, fname);
os_free(fname);
hostapd_config_free(newconf);
if (!iface) {
wpa_printf(MSG_ERROR,
"Failed to initialize interface on config reload");
return -1;
}
iface->interfaces = interfaces;
interfaces->iface[interfaces->count] = iface;
interfaces->count++;
res = hostapd_enable_iface(iface);
if (res < 0)
wpa_printf(MSG_ERROR,
"Failed to enable interface on config reload");
return res;
}
iface->conf = newconf; iface->conf = newconf;
for (j = 0; j < iface->num_bss; j++) { for (j = 0; j < iface->num_bss; j++) {