irmd: flow allocation and fast path

This commit has a first implementation of flow allocation (the "slow
path") and read/write (the "fast path") for ouroboros. It provides
basic but unstable communications over the shared memory.

It required a lot of changes all over the stack, and fixes a number of
previously undetected issues.

This PR still need heavy revision regarding data model, locking and
cleanup.

lib/dev: modifications to the API. It now uses an ap_init() call to
set the AP name and sets the Instance ID to the pid of the process. It
also binds the AP to the shared memory and creates tables for mappings
in the fast path. A call to ap_fini() releases the resources.

lib/shm_ap_rbuff: added ring buffer for data exchange between
processes in the fast path. It passes an index in the shm_du_map.

lib/shm_du_map: rewrote API to work with calls from dev.c. Garbage
collector added. Tests updated to new API.

ipcpd/ipcp-data: removed everything related to flows, as these are
universal for all ap's and kept in ap_data (dev.c), or similar structs
for shim ipcps.

shim-udp: added flow allocator and read/write functions and shm
elements.

irmd: revised data model and structures necessary for flow allocation.

tools: echo updated to new dev.h API.

messaging system was updated to comply with new flow allocation
messages. All exchanges use pid and port_id to bootstrap the fast
path.

1 files changed, 34 insertions, 31 deletions

diff --git a/src/lib/ipcp.c b/src/lib/ipcp.c
index 387572b3..75676915 100644
--- a/src/lib/ipcp.c
+++ b/src/lib/ipcp.c
@@ -121,6 +121,8 @@ pid_t ipcp_create(char *         ipcp_name,
                 return pid;
         }
 
+        /* clear fd table */
+
         if (ipcp_type == IPCP_NORMAL)
                 exec_name = IPCP_NORMAL_EXEC;
         else if (ipcp_type == IPCP_SHIM_UDP)
@@ -286,13 +288,8 @@ int ipcp_enroll(pid_t pid,
                 return -EINVAL;
 
         msg.code        = IPCP_MSG_CODE__IPCP_ENROLL;
-        msg.member_name = malloc(sizeof(*(msg.member_name)));
-        if (msg.member_name == NULL) {
-                LOG_ERR("Failed to malloc.");
-                return -1;
-        }
-        msg.n_1_dif     = n_1_dif;
         msg.member_name = member_name;
+        msg.n_1_dif     = n_1_dif;
 
         recv_msg = send_recv_ipcp_msg(pid, &msg);
         if (recv_msg == NULL) {
@@ -323,8 +320,8 @@ int ipcp_name_reg(pid_t    pid,
         if (name == NULL)
                 return -1;
 
-        msg.code          = IPCP_MSG_CODE__IPCP_NAME_REG;
-        msg.name          = name;
+        msg.code = IPCP_MSG_CODE__IPCP_NAME_REG;
+        msg.name = name;
 
         recv_msg = send_recv_ipcp_msg(pid, &msg);
         if (recv_msg == NULL)
@@ -368,6 +365,7 @@ int ipcp_name_unreg(pid_t  pid,
 
 int ipcp_flow_alloc(pid_t             pid,
                     uint32_t          port_id,
+                    pid_t             n_pid,
                     char *            dst_name,
                     char *            src_ap_name,
                     char *            src_ae_name,
@@ -381,17 +379,19 @@ int ipcp_flow_alloc(pid_t             pid,
                 return -EINVAL;
 
         msg.code        = IPCP_MSG_CODE__IPCP_FLOW_ALLOC;
+        msg.has_port_id = true;
+        msg.port_id     = port_id;
+        msg.has_pid     = true;
+        msg.pid         = n_pid;
         msg.src_ap_name = src_ap_name;
         msg.src_ae_name = src_ae_name;
         msg.dst_name    = dst_name;
-        msg.port_id     = port_id;
-        msg.has_port_id = true;
 
         recv_msg = send_recv_ipcp_msg(pid, &msg);
         if (recv_msg == NULL)
                 return -1;
 
-        if (recv_msg->has_result == false) {
+        if (!recv_msg->has_result) {
                 ipcp_msg__free_unpacked(recv_msg, NULL);
                 return -1;
         }
@@ -404,17 +404,20 @@ int ipcp_flow_alloc(pid_t             pid,
 
 int ipcp_flow_alloc_resp(pid_t    pid,
                          uint32_t port_id,
-                         int      result)
+                         pid_t    n_pid,
+                         int      response)
 {
         ipcp_msg_t msg = IPCP_MSG__INIT;
         ipcp_msg_t * recv_msg = NULL;
         int ret = -1;
 
-        msg.code        = IPCP_MSG_CODE__IPCP_FLOW_ALLOC_RESP;
-        msg.has_port_id = true;
-        msg.port_id     = port_id;
-        msg.has_result  = true;
-        msg.result      = result;
+        msg.code         = IPCP_MSG_CODE__IPCP_FLOW_ALLOC_RESP;
+        msg.has_port_id  = true;
+        msg.port_id      = port_id;
+        msg.has_pid      = true;
+        msg.pid          = n_pid;
+        msg.has_response = true;
+        msg.response     = response;
 
         recv_msg = send_recv_ipcp_msg(pid, &msg);
         if (recv_msg == NULL)
@@ -431,38 +434,38 @@ int ipcp_flow_alloc_resp(pid_t    pid,
         return ret;
 }
 
-int ipcp_flow_req_arr(pid_t    pid,
-                      char *   dst_name,
-                      char *   src_ap_name,
-                      char *   src_ae_name)
+int ipcp_flow_req_arr(pid_t  pid,
+                      char * dst_name,
+                      char * src_ap_name,
+                      char * src_ae_name)
 {
         irm_msg_t msg = IRM_MSG__INIT;
         irm_msg_t * recv_msg = NULL;
-        int fd = -1;
+        int port_id = -1;
 
         if (src_ap_name == NULL || src_ae_name == NULL)
                 return -EINVAL;
 
         msg.code          = IRM_MSG_CODE__IPCP_FLOW_REQ_ARR;
+        msg.has_pid       = true;
+        msg.pid           = pid;
         msg.dst_name      = dst_name;
         msg.ap_name       = src_ap_name;
         msg.ae_name       = src_ae_name;
-        msg.pid           = pid;
-        msg.has_pid       = true;
 
         recv_msg = send_recv_irm_msg(&msg);
         if (recv_msg == NULL)
                 return -1;
 
-        if (recv_msg->has_fd == false) {
+        if (!recv_msg->has_port_id) {
                 irm_msg__free_unpacked(recv_msg, NULL);
                 return -1;
         }
 
-        fd = recv_msg->fd;
+        port_id = recv_msg->port_id;
         irm_msg__free_unpacked(recv_msg, NULL);
 
-        return fd;
+        return port_id;
 }
 
 int ipcp_flow_alloc_reply(pid_t    pid,
@@ -509,11 +512,11 @@ int ipcp_flow_dealloc(pid_t    pid,
 
                 recv_msg = send_recv_ipcp_msg(pid, &msg);
                 if (recv_msg == NULL)
-                        return -1;
+                        return 0;
 
                 if (recv_msg->has_result == false) {
                         ipcp_msg__free_unpacked(recv_msg, NULL);
-                        return -1;
+                        return 0;
                 }
 
                 ret = recv_msg->result;
@@ -531,11 +534,11 @@ int ipcp_flow_dealloc(pid_t    pid,
 
                 recv_msg = send_recv_irm_msg(&msg);
                 if (recv_msg == NULL)
-                        return -1;
+                        return 0;
 
                 if (recv_msg->has_result == false) {
                         irm_msg__free_unpacked(recv_msg, NULL);
-                        return -1;
+                        return 0;
                 }
 
                 ret = recv_msg->result;