SELinux: break ocontext reading into a separate function

Move the reading of ocontext type data out of policydb_read() in a separate
function ocontext_read()
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NStephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

security/selinux/ss/policydb.c

@@ -1901,6 +1901,136 @@ static int genfs_read(struct policydb *p, void *fp)
 	return rc;
 }
 
+static int ocontext_read(struct policydb *p, struct policydb_compat_info *info,
+			 void *fp)
+{
+	int i, j, rc;
+	u32 nel, len;
+	__le32 buf[3];
+	struct ocontext *l, *c;
+	u32 nodebuf[8];
+
+	for (i = 0; i < info->ocon_num; i++) {
+		rc = next_entry(buf, fp, sizeof(u32));
+		if (rc)
+			goto out;
+		nel = le32_to_cpu(buf[0]);
+
+		l = NULL;
+		for (j = 0; j < nel; j++) {
+			rc = -ENOMEM;
+			c = kzalloc(sizeof(*c), GFP_KERNEL);
+			if (!c)
+				goto out;
+			if (l)
+				l->next = c;
+			else
+				p->ocontexts[i] = c;
+			l = c;
+
+			switch (i) {
+			case OCON_ISID:
+				rc = next_entry(buf, fp, sizeof(u32));
+				if (rc)
+					goto out;
+
+				c->sid[0] = le32_to_cpu(buf[0]);
+				rc = context_read_and_validate(&c->context[0], p, fp);
+				if (rc)
+					goto out;
+				break;
+			case OCON_FS:
+			case OCON_NETIF:
+				rc = next_entry(buf, fp, sizeof(u32));
+				if (rc)
+					goto out;
+				len = le32_to_cpu(buf[0]);
+
+				rc = -ENOMEM;
+				c->u.name = kmalloc(len + 1, GFP_KERNEL);
+				if (!c->u.name)
+					goto out;
+
+				rc = next_entry(c->u.name, fp, len);
+				if (rc)
+					goto out;
+
+				c->u.name[len] = 0;
+				rc = context_read_and_validate(&c->context[0], p, fp);
+				if (rc)
+					goto out;
+				rc = context_read_and_validate(&c->context[1], p, fp);
+				if (rc)
+					goto out;
+				break;
+			case OCON_PORT:
+				rc = next_entry(buf, fp, sizeof(u32)*3);
+				if (rc)
+					goto out;
+				c->u.port.protocol = le32_to_cpu(buf[0]);
+				c->u.port.low_port = le32_to_cpu(buf[1]);
+				c->u.port.high_port = le32_to_cpu(buf[2]);
+				rc = context_read_and_validate(&c->context[0], p, fp);
+				if (rc)
+					goto out;
+				break;
+			case OCON_NODE:
+				rc = next_entry(nodebuf, fp, sizeof(u32) * 2);
+				if (rc)
+					goto out;
+				c->u.node.addr = nodebuf[0]; /* network order */
+				c->u.node.mask = nodebuf[1]; /* network order */
+				rc = context_read_and_validate(&c->context[0], p, fp);
+				if (rc)
+					goto out;
+				break;
+			case OCON_FSUSE:
+				rc = next_entry(buf, fp, sizeof(u32)*2);
+				if (rc)
+					goto out;
+
+				rc = -EINVAL;
+				c->v.behavior = le32_to_cpu(buf[0]);
+				if (c->v.behavior > SECURITY_FS_USE_NONE)
+					goto out;
+
+				rc = -ENOMEM;
+				len = le32_to_cpu(buf[1]);
+				c->u.name = kmalloc(len + 1, GFP_KERNEL);
+				if (!c->u.name)
+					goto out;
+
+				rc = next_entry(c->u.name, fp, len);
+				if (rc)
+					goto out;
+				c->u.name[len] = 0;
+				rc = context_read_and_validate(&c->context[0], p, fp);
+				if (rc)
+					goto out;
+				break;
+			case OCON_NODE6: {
+				int k;
+
+				rc = next_entry(nodebuf, fp, sizeof(u32) * 8);
+				if (rc)
+					goto out;
+				for (k = 0; k < 4; k++)
+					c->u.node6.addr[k] = nodebuf[k];
+				for (k = 0; k < 4; k++)
+					c->u.node6.mask[k] = nodebuf[k+4];
+				rc = context_read_and_validate(&c->context[0], p, fp);
+				if (rc)
+					goto out;
+				break;
+			}
+			}
+		}
+	}
+	rc = 0;
+out:
+	return rc;
+}
+
 /*
  * Read the configuration data from a policy database binary
  * representation file into a policy database structure.
@@ -1909,10 +2039,8 @@ int policydb_read(struct policydb *p, void *fp)
 {
 	struct role_allow *ra, *lra;
 	struct role_trans *tr, *ltr;
-	struct ocontext *l, *c;
 	int i, j, rc;
 	__le32 buf[4];
-	u32 nodebuf[8];
 	u32 len, nprim, nel;
 
 	char *policydb_str;
@@ -2117,115 +2245,9 @@ int policydb_read(struct policydb *p, void *fp)
 	if (!p->process_trans_perms)
 		goto bad;
 
-	for (i = 0; i < info->ocon_num; i++) {
-		rc = next_entry(buf, fp, sizeof(u32));
-		if (rc < 0)
-			goto bad;
-		nel = le32_to_cpu(buf[0]);
-		l = NULL;
-		for (j = 0; j < nel; j++) {
-			c = kzalloc(sizeof(*c), GFP_KERNEL);
-			if (!c) {
-				rc = -ENOMEM;
-				goto bad;
-			}
-			if (l)
-				l->next = c;
-			else
-				p->ocontexts[i] = c;
-			l = c;
-			rc = -EINVAL;
-			switch (i) {
-			case OCON_ISID:
-				rc = next_entry(buf, fp, sizeof(u32));
-				if (rc < 0)
-					goto bad;
-				c->sid[0] = le32_to_cpu(buf[0]);
-				rc = context_read_and_validate(&c->context[0], p, fp);
-				if (rc)
-					goto bad;
-				break;
-			case OCON_FS:
-			case OCON_NETIF:
-				rc = next_entry(buf, fp, sizeof(u32));
-				if (rc < 0)
-					goto bad;
-				len = le32_to_cpu(buf[0]);
-				c->u.name = kmalloc(len + 1, GFP_KERNEL);
-				if (!c->u.name) {
-					rc = -ENOMEM;
-					goto bad;
-				}
-				rc = next_entry(c->u.name, fp, len);
-				if (rc < 0)
-					goto bad;
-				c->u.name[len] = 0;
-				rc = context_read_and_validate(&c->context[0], p, fp);
-				if (rc)
-					goto bad;
-				rc = context_read_and_validate(&c->context[1], p, fp);
-				if (rc)
-					goto bad;
-				break;
-			case OCON_PORT:
-				rc = next_entry(buf, fp, sizeof(u32)*3);
-				if (rc < 0)
-					goto bad;
-				c->u.port.protocol = le32_to_cpu(buf[0]);
-				c->u.port.low_port = le32_to_cpu(buf[1]);
-				c->u.port.high_port = le32_to_cpu(buf[2]);
-				rc = context_read_and_validate(&c->context[0], p, fp);
-				if (rc)
-					goto bad;
-				break;
-			case OCON_NODE:
-				rc = next_entry(nodebuf, fp, sizeof(u32) * 2);
-				if (rc < 0)
-					goto bad;
-				c->u.node.addr = nodebuf[0]; /* network order */
-				c->u.node.mask = nodebuf[1]; /* network order */
-				rc = context_read_and_validate(&c->context[0], p, fp);
-				if (rc)
-					goto bad;
-				break;
-			case OCON_FSUSE:
-				rc = next_entry(buf, fp, sizeof(u32)*2);
-				if (rc < 0)
-					goto bad;
-				c->v.behavior = le32_to_cpu(buf[0]);
-				if (c->v.behavior > SECURITY_FS_USE_NONE)
-					goto bad;
-				len = le32_to_cpu(buf[1]);
-				c->u.name = kmalloc(len + 1, GFP_KERNEL);
-				if (!c->u.name) {
-					rc = -ENOMEM;
-					goto bad;
-				}
-				rc = next_entry(c->u.name, fp, len);
-				if (rc < 0)
-					goto bad;
-				c->u.name[len] = 0;
-				rc = context_read_and_validate(&c->context[0], p, fp);
-				if (rc)
-					goto bad;
-				break;
-			case OCON_NODE6: {
-				int k;
-
-				rc = next_entry(nodebuf, fp, sizeof(u32) * 8);
-				if (rc < 0)
-					goto bad;
-				for (k = 0; k < 4; k++)
-					c->u.node6.addr[k] = nodebuf[k];
-				for (k = 0; k < 4; k++)
-					c->u.node6.mask[k] = nodebuf[k+4];
-				if (context_read_and_validate(&c->context[0], p, fp))
-					goto bad;
-				break;
-			}
-			}
-		}
-	}
+	rc = ocontext_read(p, info, fp);
+	if (rc)
+		goto bad;
 
 	rc = genfs_read(p, fp);
 	if (rc)