Support machines with multiple NICs

awscrt/s3.py

@@ -205,6 +205,13 @@ class S3Client(NativeResource):
             client can use for buffering data for requests.
             Default values scale with target throughput and are currently
             between 2GiB and 8GiB (may change in future)
+
+        network_interface_names: (Optional[list(str)]) A list of network interface names. The client will distribute the
+            connections across network interfaces provided in this list. If any interface name is invalid, goes down,
+            or has any issues like network access, you will see connection failures.
+            This option is only supported on Linux, MacOS, and platforms that have either SO_BINDTODEVICE or IP_BOUND_IF. It
+            is not supported on Windows. `AWS_ERROR_PLATFORM_NOT_SUPPORTED` will be raised on unsupported platforms. On
+            Linux, SO_BINDTODEVICE is used and requires kernel version >= 5.7 or root privileges.
     """
 
     __slots__ = ('shutdown_event', '_region')
@@ -222,13 +229,17 @@ def __init__(
             multipart_upload_threshold=None,
             throughput_target_gbps=None,
             enable_s3express=False,
-            memory_limit=None):
+            memory_limit=None,
+            network_interface_names=None):
         assert isinstance(bootstrap, ClientBootstrap) or bootstrap is None
         assert isinstance(region, str)
         assert isinstance(signing_config, AwsSigningConfig) or signing_config is None
         assert isinstance(credential_provider, AwsCredentialsProvider) or credential_provider is None
         assert isinstance(tls_connection_options, TlsConnectionOptions) or tls_connection_options is None
         assert isinstance(part_size, int) or part_size is None
+        assert isinstance(network_interface_names, list) and all(isinstance(name, str)
+                                                                 for name in network_interface_names) or network_interface_names is None
+
         assert isinstance(
             throughput_target_gbps,
             int) or isinstance(
@@ -284,7 +295,8 @@ def on_shutdown():
             throughput_target_gbps,
             enable_s3express,
             memory_limit,
-            s3_client_core)
+            s3_client_core,
+            network_interface_names)
 
     def make_request(
             self,

source/s3_client.c

@@ -245,22 +245,24 @@ PyObject *aws_py_s3_client_new(PyObject *self, PyObject *args) {
 
     struct aws_allocator *allocator = aws_py_get_allocator();
 
-    PyObject *bootstrap_py;              /* O */
-    PyObject *signing_config_py;         /* O */
-    PyObject *credential_provider_py;    /* O */
-    PyObject *tls_options_py;            /* O */
-    PyObject *on_shutdown_py;            /* O */
-    struct aws_byte_cursor region;       /* s# */
-    int tls_mode;                        /* i */
-    uint64_t part_size;                  /* K */
-    uint64_t multipart_upload_threshold; /* K */
-    double throughput_target_gbps;       /* d */
-    int enable_s3express;                /* p */
-    uint64_t mem_limit;                  /* K */
-    PyObject *py_core;                   /* O */
+    PyObject *bootstrap_py;               /* O */
+    PyObject *signing_config_py;          /* O */
+    PyObject *credential_provider_py;     /* O */
+    PyObject *tls_options_py;             /* O */
+    PyObject *on_shutdown_py;             /* O */
+    struct aws_byte_cursor region;        /* s# */
+    int tls_mode;                         /* i */
+    uint64_t part_size;                   /* K */
+    uint64_t multipart_upload_threshold;  /* K */
+    double throughput_target_gbps;        /* d */
+    int enable_s3express;                 /* p */
+    uint64_t mem_limit;                   /* K */
+    PyObject *py_core;                    /* O */
+    PyObject *network_interface_names_py; /* O */
+
     if (!PyArg_ParseTuple(
             args,
-            "OOOOOs#iKKdpKO",
+            "OOOOOs#iKKdpKOO",
             &bootstrap_py,
             &signing_config_py,
             &credential_provider_py,
@@ -274,7 +276,8 @@ PyObject *aws_py_s3_client_new(PyObject *self, PyObject *args) {
             &throughput_target_gbps,
             &enable_s3express,
             &mem_limit,
-            &py_core)) {
+            &py_core,
+            &network_interface_names_py)) {
         return NULL;
     }
 
@@ -319,9 +322,22 @@ PyObject *aws_py_s3_client_new(PyObject *self, PyObject *args) {
         signing_config = &default_signing_config;
     }
 
+    struct aws_byte_cursor *network_interface_names = NULL;
+    int num_network_interface_names = 0;
+
+    if (network_interface_names_py != Py_None) {
+        if (!PyList_Check(network_interface_names_py)) {
+            PyErr_SetString(PyExc_TypeError, "Expected network_interface_names to be a list");
+            return NULL;
+        }
+        Py_ssize_t listSize = PyList_Size(network_interface_names_py);
+        num_network_interface_names = (size_t)listSize;
+    }
+
     struct s3_client_binding *s3_client = aws_mem_calloc(allocator, 1, sizeof(struct s3_client_binding));
 
     /* From hereon, we need to clean up if errors occur */
+    int result = AWS_OP_ERR;
 
     PyObject *capsule = PyCapsule_New(s3_client, s_capsule_name_s3_client, s_s3_client_capsule_destructor);
     if (!capsule) {
@@ -335,6 +351,17 @@ PyObject *aws_py_s3_client_new(PyObject *self, PyObject *args) {
 
     s3_client->py_core = py_core;
     Py_INCREF(s3_client->py_core);
+    if (num_network_interface_names > 0) {
+        network_interface_names =
+            aws_mem_calloc(allocator, num_network_interface_names, sizeof(struct aws_byte_cursor));
+        for (Py_ssize_t i = 0; i < num_network_interface_names; ++i) {
+            PyObject *strObj = PyList_GetItem(network_interface_names_py, i);
+            network_interface_names[i] = aws_byte_cursor_from_pyunicode(strObj);
+            if (network_interface_names[i].ptr == NULL) {
+                goto cleanup;
+            }
+        }
+    }
 
     struct aws_s3_client_config s3_config = {
         .region = region,
@@ -349,18 +376,23 @@ PyObject *aws_py_s3_client_new(PyObject *self, PyObject *args) {
         .shutdown_callback = s_s3_client_shutdown,
         .shutdown_callback_user_data = s3_client,
         .enable_s3express = enable_s3express,
+        .network_interface_names_array = network_interface_names,
+        .num_network_interface_names = num_network_interface_names,
     };
 
     s3_client->native = aws_s3_client_new(allocator, &s3_config);
     if (s3_client->native == NULL) {
         PyErr_SetAwsLastError();
-        goto error;
+        goto cleanup;
     }
-    aws_credentials_release(anonymous_credentials);
-    return capsule;
+    result = AWS_OP_SUCCESS;
 
-error:
+cleanup:
     aws_credentials_release(anonymous_credentials);
-    Py_DECREF(capsule);
-    return NULL;
+    aws_mem_release(allocator, network_interface_names);
+    if (result != AWS_OP_SUCCESS) {
+        Py_DECREF(capsule);
+        return NULL;
+    }
+    return capsule;
 }

test/test_s3.py

@@ -158,7 +158,8 @@ def s3_client_new(
         part_size=0,
         is_cancel_test=False,
         enable_s3express=False,
-        mem_limit=None):
+        mem_limit=None,
+        network_interface_names=None):
 
     if is_cancel_test:
         # for cancellation tests, make things slow, so it's less likely that
@@ -189,7 +190,8 @@ def s3_client_new(
         part_size=part_size,
         throughput_target_gbps=throughput_target_gbps,
         enable_s3express=enable_s3express,
-        memory_limit=mem_limit)
+        memory_limit=mem_limit,
+        network_interface_names=network_interface_names)
 
     return s3_client
 
@@ -221,6 +223,10 @@ def test_sanity_secure(self):
         s3_client = s3_client_new(True, self.region)
         self.assertIsNotNone(s3_client)
 
+    def test_sanity_network_interface_names(self):
+        s3_client = s3_client_new(True, self.region, network_interface_names=["eth0", "eth1"])
+        self.assertIsNotNone(s3_client)
+
     def test_wait_shutdown(self):
         s3_client = s3_client_new(False, self.region)
         self.assertIsNotNone(s3_client)