issue: WIP Remove VLAs to fix clang-18 build

clang-18 generates a warning that VLA is a clang extension. Allocate
the arrays on heap instead of stack.

Signed-off-by: Dmytro Podgornyi <dmytrop@nvidia.com>

src/core/dev/net_device_table_mgr.cpp

@@ -477,7 +477,7 @@ int net_device_table_mgr::global_ring_wait_for_notification_and_process_element(
 {
     ndtm_logfunc("");
     int ret_total = 0;
-    int max_fd = 16;
+    constexpr int max_fd = 16;
     struct epoll_event events[max_fd];
 
     int res = SYSCALL(epoll_wait, global_ring_epfd_get(), events, max_fd, 0);

src/core/dev/ring_tap.cpp

@@ -597,20 +597,25 @@ int ring_tap::mem_buf_tx_release(mem_buf_desc_t *buff_list, bool b_accounting, b
 
 int ring_tap::send_buffer(xlio_ibv_send_wr *wr, xlio_wr_tx_packet_attr attr)
 {
-    int ret = 0;
-    iovec iovec[wr->num_sge];
     NOT_IN_USE(attr);
 
+    struct iovec *iovec = new struct iovec[wr->num_sge];
+    if (!iovec) {
+        errno = ENOMEM;
+        return -1;
+    }
+
     for (int i = 0; i < wr->num_sge; i++) {
         iovec[i].iov_base = (void *)wr->sg_list[i].addr;
         iovec[i].iov_len = wr->sg_list[i].length;
     }
 
-    ret = SYSCALL(writev, m_tap_fd, iovec, wr->num_sge);
+    int ret = SYSCALL(writev, m_tap_fd, iovec, wr->num_sge);
     if (ret < 0) {
         ring_logdbg("writev: tap_fd %d, errno: %d\n", m_tap_fd, errno);
     }
 
+    delete[] iovec;
     return ret;
 }
 

src/core/sock/sockinfo_tcp.cpp

@@ -2225,15 +2225,20 @@ err_t sockinfo_tcp::rx_lwip_cb_recv_callback(void *arg, struct tcp_pcb *pcb, str
         }
 
         // fill io vector array with data buffer pointers
-        iovec iov[p_first_desc->rx.n_frags];
-        nr_frags = 0;
-        for (tmp = p_first_desc; tmp; tmp = tmp->p_next_desc) {
-            iov[nr_frags++] = tmp->rx.frag;
-        }
+        struct iovec *iov = new struct iovec[p_first_desc->rx.n_frags];
+        if (likely(iov)) {
+            nr_frags = 0;
+            for (tmp = p_first_desc; tmp; tmp = tmp->p_next_desc) {
+                iov[nr_frags++] = tmp->rx.frag;
+            }
 
-        // call user callback
-        callback_retval =
-            conn->m_rx_callback(conn->m_fd, nr_frags, iov, &pkt_info, conn->m_rx_callback_context);
+            // call user callback
+            callback_retval = conn->m_rx_callback(conn->m_fd, nr_frags, iov, &pkt_info,
+                                                  conn->m_rx_callback_context);
+            delete[] iov;
+        } else {
+            callback_retval = XLIO_PACKET_DROP;
+        }
     }
 
     if (callback_retval == XLIO_PACKET_DROP) {

src/core/sock/sockinfo_udp.cpp

@@ -2319,15 +2319,22 @@ inline xlio_recv_callback_retval_t sockinfo_udp::inspect_by_user_cb(mem_buf_desc
     }
 
     // fill io vector array with data buffer pointers
-    iovec iov[p_desc->rx.n_frags];
     int nr_frags = 0;
+    struct iovec *iov = new struct iovec[p_desc->rx.n_frags];
+    if (!iov) {
+        return XLIO_PACKET_DROP;
+    }
 
     for (mem_buf_desc_t *tmp = p_desc; tmp; tmp = tmp->p_next_desc) {
         iov[nr_frags++] = tmp->rx.frag;
     }
 
     // call user callback
-    return m_rx_callback(m_fd, nr_frags, iov, &pkt_info, m_rx_callback_context);
+    xlio_recv_callback_retval_t ret =
+        m_rx_callback(m_fd, nr_frags, iov, &pkt_info, m_rx_callback_context);
+
+    delete[] iov;
+    return ret;
 }
 
 /* Update completion with