discover: Respect persistent flag for network overrides

If the persistent bit is set in a IPMI network override, overwrite any
existing interface config in NVRAM with the new network override.

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>

discover/ipmi.c

@@ -223,7 +223,7 @@ bool ipmi_present(void)
 
 /* Reads and applies an IPMI interface config override, which closely follows
  * the format of an interface config struct as described in lib/types */
-void parse_ipmi_interface_override(struct config *config, uint8_t *buf,
+int parse_ipmi_interface_override(struct config *config, uint8_t *buf,
 				uint16_t len)
 {
 	struct interface_config *ifconf;
@@ -240,14 +240,14 @@ void parse_ipmi_interface_override(struct config *config, uint8_t *buf,
 
 	if (!hwsize || !ipsize) {
 		pb_log("%s: Empty response\n", __func__);
-		return;
+		return -1;
 	}
 
 	/* At the moment only support 6-byte MAC addresses */
 	if (hwsize != sizeof(ifconf->hwaddr)) {
 		pb_log("Unsupported HW address size in network override: %u\n",
 		       hwsize);
-		return;
+		return -1;
 	}
 
 	/* Sanity check the IP address size */
@@ -259,14 +259,14 @@ void parse_ipmi_interface_override(struct config *config, uint8_t *buf,
 		addr_len = INET6_ADDRSTRLEN;
 	} else {
 		pb_log("Unsupported IP address size: %u\n", ipsize);
-		return;
+		return -1;
 	}
 
 	/* Everything past here is the interface config */
 	ifconf = talloc_zero(config, struct interface_config);
 	if (!ifconf) {
 		pb_log("Failed to allocate network override\n");
-		return;
+		return -1;
 	}
 
 	/* Hardware Address */
@@ -281,15 +281,15 @@ void parse_ipmi_interface_override(struct config *config, uint8_t *buf,
 		if (ipsize + ipsize  + 1 > len - i) {
 			pb_log("Expected data greater than buffer size\n");
 			talloc_free(ifconf);
-			return;
+			return -1;
 		}
 
 		/* IP address */
 		ipstr = talloc_array(ifconf, char, addr_len);
 		if (!inet_ntop(addr_type, &buf[i], ipstr, addr_len)) {
 			pb_log("Failed to convert ipaddr: %m\n");
 			talloc_free(ifconf);
-			return;
+			return -1;
 		}
 		i += ipsize;
 
@@ -303,17 +303,19 @@ void parse_ipmi_interface_override(struct config *config, uint8_t *buf,
 		if (!inet_ntop(addr_type, &buf[i], gatewaystr, addr_len)) {
 			pb_log("Failed to convert gateway: %m\n");
 			talloc_free(ifconf);
-			return;
+			return -1;
 		}
 		ifconf->static_config.gateway = gatewaystr;
 		i += ipsize;
 	}
 
-	pb_log("Applying IPMI network config\n");
+	pb_log("Applying IPMI network interface override\n");
 
 	/* Replace any existing interface config */
 	talloc_free(config->network.interfaces);
 	config->network.n_interfaces = 1;
 	config->network.interfaces = talloc(config, struct interface_config *);
 	config->network.interfaces[0] = ifconf;
+
+	return 0;
 }

discover/ipmi.h

@@ -38,7 +38,7 @@ int ipmi_transaction(struct ipmi *ipmi, uint8_t netfn, uint8_t cmd,
 		uint8_t *resp_buf, uint16_t *resp_len,
 		int timeout_ms);
 
-void parse_ipmi_interface_override(struct config *config, uint8_t *buf,
+int parse_ipmi_interface_override(struct config *config, uint8_t *buf,
 				uint16_t len);
 
 

discover/platform-powerpc.c

@@ -1121,6 +1121,7 @@ static void get_ipmi_network_override(struct platform_powerpc *platform,
 	const uint32_t magic_value = 0x21706221;
 	uint8_t resp[resp_len];
 	uint32_t cookie;
+	bool persistent;
 	int i, rc;
 	uint8_t req[] = {
 		0x61, /* parameter selector: OEM section (network) */
@@ -1169,18 +1170,21 @@ static void get_ipmi_network_override(struct platform_powerpc *platform,
 		return;
 	}
 
-	/* Check for valid parameters. For now ignore the persistent flag */
+	/* Check that the parameters are valid */
 	if (resp[2] & 0x80) {
 		pb_debug("platform: network override is invalid/locked\n");
 		return;
 	}
 
-	/* Check for valid parameters in the boot flags section, ignoring the
-	 * persistent bit */
+	/* Check for valid parameters in the boot flags section */
 	if (!(resp[3] & 0x80)) {
 		pb_debug("platform: network override valid flag not set\n");
 		return;
 	}
+	/* Read the persistent flag; if it is set we need to save this config */
+	persistent = resp[3] & 0x40;
+	if (persistent)
+		pb_debug("platform: network override is persistent\n");
 
 	/* Check 4-byte cookie value */
 	i = 4;
@@ -1202,7 +1206,15 @@ static void get_ipmi_network_override(struct platform_powerpc *platform,
 	}
 
 	/* Interpret the rest of the interface config */
-	parse_ipmi_interface_override(config, &resp[i], resp_len - i);
+	rc = parse_ipmi_interface_override(config, &resp[i], resp_len - i);
+
+	if (!rc && persistent) {
+		/* Write this new config to NVRAM */
+		update_network_config(platform, config);
+		rc = write_nvram(platform);
+		if (rc)
+			pb_log("platform: Failed to save persistent interface override\n");
+	}
 }
 
 static int load_config(struct platform *p, struct config *config)