[PATCH 15/18] P2P2: Handle identity ID consistently within files

[Benjamin Berg]

From: Benjamin Berg <benjamin.berg at intel.com>

Using an ID to reference a specific identity= block within the same file
for the DIK has the problem that it requires the IDs to be stable.
However, we also use a static int for the ID enumeration in case
multiple files are read.

Overall, it seems like it could be better to use the DIK as an
identifier. However, we do not, so the numbering needs to be restored
consistently within the file. The straight forward way to achieve this
is to store the base of the counter as a static variable and adding it
to both the go_dik_id and the id of the identity= blocks.

For all of this to work, we also need to make sure that we write out the
values with file-local indices. As such, we need to use the position in
the internal list rather than the assigned ID when writing the values.

Fixes: 417c67468b8d ("P2P2: Add device identity block to wpa_supplicant configuration")
Fixes: ec4569174750 ("P2P2: Store ID of Device Identity block in network block")
CC: Shivani Baranwal <quic_shivbara at quicinc.com>
CC: Vinay Gannevaram <quic_vganneva at quicinc.com>
Signed-off-by: Benjamin Berg <benjamin.berg at intel.com>

---

Hi,

Could we maybe rework this to use the DIK itself in the network= block
rather than an ID to find the corresponding identity= block?

Benjamin

Signed-off-by: Benjamin Berg <benjamin.berg at intel.com>
---
 wpa_supplicant/config_file.c | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/wpa_supplicant/config_file.c b/wpa_supplicant/config_file.c
index 0012503017..e41f26841f 100644
--- a/wpa_supplicant/config_file.c
+++ b/wpa_supplicant/config_file.c
@@ -367,7 +367,8 @@ struct wpa_config * wpa_config_read(const char *name, struct wpa_config *cfgp,
 	struct wpa_config *config;
 	static int id = 0;
 	static int cred_id = 0;
-	static int identity_id = 1;
+	static int base_identity_id = 0;
+	int identity_id = base_identity_id;
 
 	if (name == NULL)
 		return NULL;
@@ -416,6 +417,7 @@ struct wpa_config * wpa_config_read(const char *name, struct wpa_config *cfgp,
 				errors++;
 				continue;
 			}
+			ssid->go_dik_id += base_identity_id;
 			ssid->ro = ro;
 			if (head == NULL) {
 				head = tail = ssid;
@@ -456,7 +458,7 @@ struct wpa_config * wpa_config_read(const char *name, struct wpa_config *cfgp,
 #endif /* CONFIG_NO_CONFIG_BLOBS */
 		} else if (os_strcmp(pos, "identity={") == 0) {
 			identity = wpa_config_read_identity(f, &line,
-							    identity_id++);
+							    ++identity_id);
 			if (!identity) {
 				wpa_printf(MSG_ERROR,
 					   "Line %d: failed to parse identity block.",
@@ -488,6 +490,8 @@ struct wpa_config * wpa_config_read(const char *name, struct wpa_config *cfgp,
 	config->cred = cred_head;
 	config->identity = identity_head;
 
+	base_identity_id = identity_id;
+
 #ifndef WPA_IGNORE_CONFIG_ERRORS
 	if (errors) {
 		if (config != cfgp)
@@ -768,7 +772,8 @@ static void write_mka_ckn(FILE *f, struct wpa_ssid *ssid)
 #endif /* CONFIG_MACSEC */
 
 
-static void wpa_config_write_network(FILE *f, struct wpa_ssid *ssid)
+static void wpa_config_write_network(FILE *f, struct wpa_ssid *ssid,
+				     struct wpa_config *config)
 {
 #define STR(t) write_str(f, #t, ssid)
 #define INT(t) write_int(f, #t, ssid->t, 0)
@@ -910,7 +915,20 @@ static void wpa_config_write_network(FILE *f, struct wpa_ssid *ssid)
 	write_p2p_client_list(f, ssid);
 	write_p2p2_client_list(f, ssid);
 	write_psk_list(f, ssid);
-	INT(go_dik_id);
+	{
+		struct wpa_dev_ik *dev_ik;
+		int i = 1, go_dik_id = 0;
+
+		for (dev_ik = config->identity;
+		     dev_ik;
+		     dev_ik = dev_ik->next, i++) {
+			if (dev_ik->id == ssid->go_dik_id) {
+				go_dik_id = i;
+				break;
+			}
+		}
+		write_int(f, "go_dik_id", go_dik_id, 0);
+	}
 #endif /* CONFIG_P2P */
 	INT(ap_max_inactivity);
 	INT(dtim_period);
@@ -1861,7 +1879,7 @@ int wpa_config_write(const char *name, struct wpa_config *config)
 		    !ssid->pmk_valid)
 			continue; /* do not save invalid network */
 		fprintf(f, "\nnetwork={\n");
-		wpa_config_write_network(f, ssid);
+		wpa_config_write_network(f, ssid, config);
 		fprintf(f, "}\n");
 	}
 
-- 
2.51.0