open_ipc_handle should use shm from handle

examples/ipc_ipcapi/ipc_ipcapi_shm.sh

@@ -20,7 +20,7 @@ UMF_LOG_VAL="level:debug;flush:debug;output:stderr;pid:yes"
 rm -f /dev/shm/${SHM_NAME}
 
 echo "Starting ipc_ipcapi_shm CONSUMER on port $PORT ..."
-UMF_LOG=$UMF_LOG_VAL ./umf_example_ipc_ipcapi_consumer $PORT $SHM_NAME &
+UMF_LOG=$UMF_LOG_VAL ./umf_example_ipc_ipcapi_consumer $PORT &
 
 echo "Waiting 1 sec ..."
 sleep 1

src/provider/provider_os_memory.c

@@ -1146,7 +1146,10 @@ typedef struct os_ipc_data_t {
     int fd;
     size_t fd_offset;
     size_t size;
-    char shm_name[NAME_MAX]; // optional - can be used or not (see below)
+    // shm_name is a Flexible Array Member because it is optional and its size
+    // varies on the Shared Memory object name
+    size_t shm_name_len;
+    char shm_name[];
 } os_ipc_data_t;
 
 static umf_result_t os_get_ipc_handle_size(void *provider, size_t *size) {
@@ -1160,13 +1163,8 @@ static umf_result_t os_get_ipc_handle_size(void *provider, size_t *size) {
         return UMF_RESULT_ERROR_INVALID_ARGUMENT;
     }
 
-    if (os_provider->shm_name[0]) {
-        // os_ipc_data_t->shm_name will be used
-        *size = sizeof(os_ipc_data_t);
-    } else {
-        // os_ipc_data_t->shm_name will NOT be used
-        *size = sizeof(os_ipc_data_t) - NAME_MAX;
-    }
+    // NOTE: +1 for '\0' at the end of the string
+    *size = sizeof(os_ipc_data_t) + strlen(os_provider->shm_name) + 1;
 
     return UMF_RESULT_SUCCESS;
 }
@@ -1195,9 +1193,10 @@ static umf_result_t os_get_ipc_handle(void *provider, const void *ptr,
     os_ipc_data->pid = utils_getpid();
     os_ipc_data->fd_offset = (size_t)value - 1;
     os_ipc_data->size = size;
-    if (os_provider->shm_name[0]) {
-        strncpy(os_ipc_data->shm_name, os_provider->shm_name, NAME_MAX - 1);
-        os_ipc_data->shm_name[NAME_MAX - 1] = '\0';
+    os_ipc_data->shm_name_len = strlen(os_provider->shm_name);
+    if (os_ipc_data->shm_name_len > 0) {
+        strncpy(os_ipc_data->shm_name, os_provider->shm_name,
+                os_ipc_data->shm_name_len);
     } else {
         os_ipc_data->fd = os_provider->fd;
     }
@@ -1222,8 +1221,12 @@ static umf_result_t os_put_ipc_handle(void *provider, void *providerIpcData) {
         return UMF_RESULT_ERROR_INVALID_ARGUMENT;
     }
 
-    if (os_provider->shm_name[0]) {
-        if (strncmp(os_ipc_data->shm_name, os_provider->shm_name, NAME_MAX)) {
+    size_t shm_name_len = strlen(os_provider->shm_name);
+    if (shm_name_len > 0) {
+        if (os_ipc_data->shm_name_len != shm_name_len) {
+            return UMF_RESULT_ERROR_INVALID_ARGUMENT;
+        } else if (strncmp(os_ipc_data->shm_name, os_provider->shm_name,
+                           shm_name_len)) {
             return UMF_RESULT_ERROR_INVALID_ARGUMENT;
         }
     } else {
@@ -1251,14 +1254,14 @@ static umf_result_t os_open_ipc_handle(void *provider, void *providerIpcData,
     umf_result_t ret = UMF_RESULT_SUCCESS;
     int fd;
 
-    if (os_provider->shm_name[0]) {
-        fd = utils_shm_open(os_provider->shm_name);
+    if (os_ipc_data->shm_name_len) {
+        fd = utils_shm_open(os_ipc_data->shm_name);
         if (fd <= 0) {
             LOG_PERR("opening a shared memory file (%s) failed",
-                     os_provider->shm_name);
+                     os_ipc_data->shm_name);
             return UMF_RESULT_ERROR_UNKNOWN;
         }
-        (void)utils_shm_unlink(os_provider->shm_name);
+        (void)utils_shm_unlink(os_ipc_data->shm_name);
     } else {
         umf_result_t umf_result =
             utils_duplicate_fd(os_ipc_data->pid, os_ipc_data->fd, &fd);

test/common/ipc_common.c

@@ -15,7 +15,7 @@
 #include "ipc_common.h"
 
 #define INET_ADDR "127.0.0.1"
-#define MSG_SIZE 1024
+#define MSG_SIZE 1024 * 8
 
 // consumer's response message
 #define CONSUMER_MSG                                                           \
@@ -33,6 +33,10 @@ Generally communication between the producer and the consumer looks like:
 - Producer creates a socket
 - Producer connects to the consumer
 - Consumer connects at IP 127.0.0.1 and a port to the producer
+- Producer sends the IPC handle size to the consumer
+- Consumer receives the IPC handle size from the producer
+- Consumer sends the confirmation (IPC handle size) to the producer
+- Producer receives the confirmation (IPC handle size) from the consumer
 - Producer sends the IPC handle to the consumer
 - Consumer receives the IPC handle from the producer
 - Consumer opens the IPC handle received from the producer
@@ -127,29 +131,36 @@ int run_consumer(int port, umf_memory_provider_ops_t *provider_ops,
         return -1;
     }
 
-    // get the size of the IPC handle
-    size_t IPC_handle_size;
-    umf_result = umfMemoryProviderGetIPCHandleSize(provider, &IPC_handle_size);
-    if (umf_result != UMF_RESULT_SUCCESS) {
-        fprintf(stderr,
-                "[consumer] ERROR: getting size of the IPC handle failed\n");
+    producer_socket = consumer_connect(port);
+    if (producer_socket < 0) {
         goto err_umfMemoryProviderDestroy;
     }
 
     // allocate the zeroed receive buffer
-    char *recv_buffer = calloc(1, IPC_handle_size);
+    char *recv_buffer = calloc(1, MSG_SIZE);
     if (!recv_buffer) {
         fprintf(stderr, "[consumer] ERROR: out of memory\n");
         goto err_umfMemoryProviderDestroy;
     }
 
-    producer_socket = consumer_connect(port);
-    if (producer_socket < 0) {
-        goto err_umfMemoryProviderDestroy;
+    // get the size of the IPC handle from the producer
+    size_t IPC_handle_size;
+    ssize_t recv_len = recv(producer_socket, recv_buffer, MSG_SIZE, 0);
+    if (recv_len < 0) {
+        fprintf(stderr, "[consumer] ERROR: recv() failed\n");
+        goto err_close_producer_socket;
     }
+    IPC_handle_size = *(size_t *)recv_buffer;
+    fprintf(stderr, "[consumer] Got the size of the IPC handle: %zu\n",
+            IPC_handle_size);
+
+    // send confirmation to the producer (IPC handle size)
+    send(producer_socket, &IPC_handle_size, sizeof(IPC_handle_size), 0);
+    fprintf(stderr,
+            "[consumer] Send the confirmation (IPC handle size) to producer\n");
 
-    // receive a producer's message
-    ssize_t recv_len = recv(producer_socket, recv_buffer, IPC_handle_size, 0);
+    // receive IPC handle from the producer
+    recv_len = recv(producer_socket, recv_buffer, MSG_SIZE, 0);
     if (recv_len < 0) {
         fprintf(stderr, "[consumer] ERROR: recv() failed\n");
         goto err_close_producer_socket;
@@ -388,6 +399,44 @@ int run_producer(int port, umf_memory_provider_ops_t *provider_ops,
         goto err_PutIPCHandle;
     }
 
+    // send the IPC_handle_size to the consumer
+    ssize_t len =
+        send(producer_socket, &IPC_handle_size, sizeof(IPC_handle_size), 0);
+    if (len < 0) {
+        fprintf(stderr, "[producer] ERROR: unable to send the message\n");
+        goto err_close_producer_socket;
+    }
+
+    fprintf(stderr,
+            "[producer] Sent the size of the IPC handle (%zu) to the consumer "
+            "(sent %zu bytes)\n",
+            IPC_handle_size, len);
+
+    // zero the consumer_message buffer
+    memset(consumer_message, 0, sizeof(consumer_message));
+
+    // receive the consumer's confirmation - IPC handle size
+    len = recv(producer_socket, consumer_message, sizeof(consumer_message), 0);
+    if (len < 0) {
+        fprintf(stderr, "[producer] ERROR: error while receiving the "
+                        "confirmation from the consumer\n");
+        goto err_close_producer_socket;
+    }
+
+    size_t conf_IPC_handle_size = *(size_t *)consumer_message;
+    if (conf_IPC_handle_size == IPC_handle_size) {
+        fprintf(stderr,
+                "[producer] Received the correct confirmation (%zu) from the "
+                "consumer (%zu bytes)\n",
+                conf_IPC_handle_size, len);
+    } else {
+        fprintf(stderr,
+                "[producer] Received an INCORRECT confirmation (%zu) from the "
+                "consumer (%zu bytes)\n",
+                conf_IPC_handle_size, len);
+        goto err_close_producer_socket;
+    }
+
     // send the IPC_handle of IPC_handle_size to the consumer
     if (send(producer_socket, IPC_handle, IPC_handle_size, 0) < 0) {
         fprintf(stderr, "[producer] ERROR: unable to send the message\n");

test/ipc_os_prov_shm.sh

@@ -20,7 +20,7 @@ UMF_LOG_VAL="level:debug;flush:debug;output:stderr;pid:yes"
 rm -f /dev/shm/${SHM_NAME}
 
 echo "Starting ipc_os_prov_shm CONSUMER on port $PORT ..."
-UMF_LOG=$UMF_LOG_VAL ./umf_test-ipc_os_prov_consumer $PORT $SHM_NAME &
+UMF_LOG=$UMF_LOG_VAL ./umf_test-ipc_os_prov_consumer $PORT &
 
 echo "Waiting 1 sec ..."
 sleep 1