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.

2 files changed, 46 insertions, 22 deletions

diff --git a/src/tools/echo/echo_client.c b/src/tools/echo/echo_client.c
index 8d3fc322..36942028 100644
--- a/src/tools/echo/echo_client.c
+++ b/src/tools/echo/echo_client.c
@@ -23,19 +23,23 @@
 #define CLIENT_AP_NAME "echo-client"
 
 #include <ouroboros/dev.h>
+#include <stdlib.h>
 
 int client_main()
 {
         int fd = 0;
         int result = 0;
-        uint8_t buf[BUF_SIZE];
+        char buf[BUF_SIZE];
         char * message  = "Client says hi!";
         ssize_t count = 0;
 
-        fd = flow_alloc(SERVER_AP_NAME, CLIENT_AP_NAME,
-                        NULL, NULL, 0);
+        if(ap_init(CLIENT_AP_NAME))
+                return -1;
+
+        fd = flow_alloc(SERVER_AP_NAME, NULL, NULL);
         if (fd < 0) {
                 printf("Failed to allocate flow\n");
+                ap_fini();
                 return -1;
         }
 
@@ -43,12 +47,14 @@ int client_main()
         if (result < 0) {
                 printf("Flow allocation refused\n");
                 flow_dealloc(fd);
+                ap_fini();
                 return -1;
         }
 
         if (flow_write(fd, message, strlen(message) + 1) == -1) {
                 printf("Failed to write SDU\n");
                 flow_dealloc(fd);
+                ap_fini();
                 return -1;
         }
 
@@ -56,6 +62,7 @@ int client_main()
         if (count < 0) {
                 printf("Failed to read SDU\n");
                 flow_dealloc(fd);
+                ap_fini();
                 return -1;
         }
 
@@ -63,5 +70,7 @@ int client_main()
 
         flow_dealloc(fd);
 
+        ap_fini();
+
         return 0;
 }
diff --git a/src/tools/echo/echo_server.c b/src/tools/echo/echo_server.c
index e457e22b..4b1a17b1 100644
--- a/src/tools/echo/echo_server.c
+++ b/src/tools/echo/echo_server.c
@@ -20,6 +20,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <ouroboros/config.h>
+
 #include <stdbool.h>
 #include <signal.h>
 #include <unistd.h>
@@ -27,71 +29,82 @@
 
 #include <ouroboros/dev.h>
 
+#ifdef OUROBOROS_CONFIG_DEBUG
+ #define OUROBOROS_PREFIX "echo-server"
+ #include <ouroboros/logs.h>
+#endif
+
 #define DIF_NAME "*"
 
 void shutdown_server(int signo)
 {
         char * dif = DIF_NAME;
 
-        if (ap_unreg(SERVER_AP_NAME, &dif, 1)) {
-                printf("Failed to unregister application\n");
+        if (ap_unreg(&dif, 1)) {
+                printf("Failed to unregister application.\n");
+                ap_fini();
                 exit(EXIT_FAILURE);
         }
 
+        ap_fini();
         exit(EXIT_SUCCESS);
 }
 
 int server_main()
 {
-        int server_fd = 0;
-        int client_fd = 0;
+        int    server_fd = 0;
+        int    client_fd = 0;
         char * dif = DIF_NAME;
         char * client_name = NULL;
-        uint8_t buf[BUF_SIZE];
+        char   buf[BUF_SIZE];
         ssize_t count = 0;
 
-        printf("Starting the server\n");
+        printf("Starting the server.\n");
 
         /* Manual cleanup is required for now */
         if (signal(SIGINT, shutdown_server) == SIG_ERR) {
-                printf("Can't install signal handler\n");
+                printf("Can't install signal handler.\n");
                 return -1;
         }
 
-        server_fd = ap_reg(SERVER_AP_NAME, &dif, 1);
-        if (server_fd < 0) {
-                printf("Failed to register application\n");
+        if(ap_init(SERVER_AP_NAME)) {
                 return -1;
         }
 
-        printf("Echo server started...\n");
+        server_fd = ap_reg(&dif, 1);
+        if (server_fd < 0) {
+                printf("Failed to register application.\n");
+                ap_fini();
+                return -1;
+        }
 
         while (true) {
                 client_fd = flow_accept(server_fd,
-                                        client_name, NULL);
+                                        &client_name, NULL);
                 if (client_fd < 0) {
-                        continue;
+                        printf("Failed to accept flow.\n");
+                        break;
                 }
 
-                printf("New flow from %s\n", client_name);
+                printf("New flow from %s.\n", client_name);
 
                 if (flow_alloc_resp(client_fd, 0)) {
-                        printf("Failed to give an allocate response\n");
+                        printf("Failed to give an allocate response.\n");
                         flow_dealloc(client_fd);
                         continue;
                 }
 
-                count = flow_read(client_fd, buf, BUF_SIZE);
+                count = flow_read(client_fd, (void **) &buf, BUF_SIZE);
                 if (count < 0) {
-                        printf("Failed to read SDU\n");
+                        printf("Failed to read SDU.\n");
                         flow_dealloc(client_fd);
                         continue;
                 }
 
-                printf("Message from client is %.*s\n", (int) count, buf);
+                printf("Message from client is %.*s.\n", (int) count, buf);
 
                 if (flow_write(client_fd, buf, count) == -1) {
-                        printf("Failed to write SDU\n");
+                        printf("Failed to write SDU.\n");
                         flow_dealloc(client_fd);
                         continue;
                 }
@@ -99,5 +112,7 @@ int server_main()
                 flow_dealloc(client_fd);
         }
 
+        ap_fini();
+
         return 0;
 }