lib: Exchange protocol info during CACEP

This exchanges a protocol name, a protocol version and concrete syntax
for the protocol upon CACEP. For CDAP, only version 1 and GPB are
supported. No lists for other supported versions or syntaxes are
exchanged (but the proto file supports it). CACEP fails if there is a
mismatch between the protocol names, version and syntax specified by
the communicating parties.

1 files changed, 123 insertions, 6 deletions

diff --git a/src/lib/pol/cacep_anonymous_auth.c b/src/lib/pol/cacep_anonymous_auth.c
index d450fdc5..1ad8a533 100644
--- a/src/lib/pol/cacep_anonymous_auth.c
+++ b/src/lib/pol/cacep_anonymous_auth.c
@@ -24,7 +24,10 @@
 #include <ouroboros/config.h>
 #include <ouroboros/cacep.h>
 #include <ouroboros/time_utils.h>
+#include <ouroboros/dev.h>
+#include <ouroboros/errno.h>
 
+#include "cacep_proto.h"
 #include "cacep_anonymous_auth.h"
 
 #include <stdlib.h>
@@ -32,6 +35,11 @@
 #include <string.h>
 #include <stdio.h>
 
+#include "cacep_anonymous_auth.pb-c.h"
+typedef CacepAnonymousAuthMsg cacep_anonymous_auth_msg_t;
+typedef CacepProtoMsg cacep_proto_msg_t;
+
+#define BUF_SIZE 2048
 #define NAME_LEN 8
 
 /* this policy generates a hex string */
@@ -61,21 +69,130 @@ static struct cacep_info * anonymous_info(void)
         return info;
 }
 
+static struct cacep_info * read_msg(int fd)
+{
+        struct cacep_info *          tmp;
+        uint8_t                      buf[BUF_SIZE];
+        cacep_anonymous_auth_msg_t * msg;
+        ssize_t                      len;
+
+        len = flow_read(fd, buf, BUF_SIZE);
+        if (len < 0)
+                return NULL;
+
+        msg = cacep_anonymous_auth_msg__unpack(NULL, len, buf);
+        if (msg == NULL)
+                return NULL;
+
+        tmp = anonymous_info();
+        if (tmp == NULL) {
+                cacep_anonymous_auth_msg__free_unpacked(msg, NULL);
+                return NULL;
+        }
+
+        tmp->proto.protocol = strdup(msg->proto->protocol);
+        if (tmp->proto.protocol == NULL) {
+                free(tmp);
+                cacep_anonymous_auth_msg__free_unpacked(msg, NULL);
+                return NULL;
+        }
+
+        tmp->proto.pref_version = msg->proto->pref_version;
+        tmp->proto.pref_syntax  = code_to_syntax(msg->proto->pref_syntax);
+        if (tmp->proto.pref_syntax < 0) {
+                free(tmp->proto.protocol);
+                free(tmp);
+                cacep_anonymous_auth_msg__free_unpacked(msg, NULL);
+                return NULL;
+        }
+
+        cacep_anonymous_auth_msg__free_unpacked(msg, NULL);
+
+        return tmp;
+}
+
+static int send_msg(int                       fd,
+                    const struct cacep_info * info)
+{
+        cacep_anonymous_auth_msg_t msg  = CACEP_ANONYMOUS_AUTH_MSG__INIT;
+        cacep_proto_msg_t          cmsg = CACEP_PROTO_MSG__INIT;
+        int                        ret  = 0;
+        uint8_t *                  data = NULL;
+        size_t                     len  = 0;
+
+        cmsg.protocol     = info->proto.protocol;
+        cmsg.pref_version = info->proto.pref_version;
+        cmsg.pref_syntax  = syntax_to_code(info->proto.pref_syntax);
+        if (cmsg.pref_syntax < 0)
+                return -1;
+
+        msg.proto = &cmsg;
+
+        len = cacep_anonymous_auth_msg__get_packed_size(&msg);
+        if (len == 0)
+                return -1;
+
+        data = malloc(len);
+        if (data == NULL)
+                return -ENOMEM;
+
+        cacep_anonymous_auth_msg__pack(&msg, data);
+
+        if (flow_write(fd, data, len) < 0)
+                ret = -1;
+
+        free(data);
+
+        return ret;
+}
+
 struct cacep_info * cacep_anonymous_auth(int                       fd,
                                          const struct cacep_info * info)
 {
-        (void) fd;
-        (void) info;
+        struct cacep_info * tmp;
 
-        return anonymous_info();
+        if (send_msg(fd, info))
+                return NULL;
+
+        tmp = read_msg(fd);
+        if (tmp == NULL)
+                return NULL;
+
+        if (strcmp(info->proto.protocol, tmp->proto.protocol) ||
+            info->proto.pref_version != tmp->proto.pref_version ||
+            info->proto.pref_syntax != tmp->proto.pref_syntax) {
+                free(tmp);
+                return NULL;
+        }
+
+        tmp->data = NULL;
+
+        return tmp;
 }
 
 
 struct cacep_info * cacep_anonymous_auth_wait(int                       fd,
                                               const struct cacep_info * info)
 {
-        (void) fd;
-        (void) info;
+        struct cacep_info * tmp;
+
+        tmp = read_msg(fd);
+        if (tmp == NULL)
+                return NULL;
+
+        if (send_msg(fd, info)) {
+                free(tmp);
+                return NULL;
+        }
+
+        if (strcmp(info->proto.protocol, tmp->proto.protocol) ||
+            info->proto.pref_version != tmp->proto.pref_version ||
+            info->proto.pref_syntax != tmp->proto.pref_syntax) {
+                free(tmp);
+                return NULL;
+        }
+
+        tmp->data = NULL;
 
-        return anonymous_info();
+        return tmp;
 }