fix compiler warnings: C23 label+declaration, uint16_t overflow check

src/etcp.c

@@ -71,8 +71,8 @@ static void feed_dgram_to_asm(struct ETCP_CONN* etcp, struct PKTNORM* pn,
                                uint8_t* dgram, uint16_t dgram_len,
                                uint8_t** asm_buf, uint16_t* asm_len, uint16_t* asm_cap,
                                uint32_t* returned) {
-    uint16_t need = *asm_len + dgram_len;
-    if (need > ASM_BUF_MAX_SIZE) {
+    uint32_t need = (uint32_t)*asm_len + dgram_len;
+    if (need >= ASM_BUF_MAX_SIZE) {
         DEBUG_ERROR(DEBUG_CATEGORY_ETCP, "[%s] assembly buffer would exceed max size %d", etcp->log_name, ASM_BUF_MAX_SIZE);
         return;
     }

src/lwip_tcp/lwip_tcp.c

@@ -543,6 +543,8 @@ static uint16_t tcp_new_port(struct tcp_pcb *pcb)
 {
     struct lwip_tcp_ctx *ctx = pcb->ctx;
     uint16_t n = 0;
+    struct tcp_pcb *lists[4];
+    int i;
 
     ctx->port_seed++;
     if (ctx->port_seed < TCP_LOCAL_PORT_RANGE_START || ctx->port_seed >= TCP_LOCAL_PORT_RANGE_END) {
@@ -550,8 +552,8 @@ static uint16_t tcp_new_port(struct tcp_pcb *pcb)
     }
 
  again:
-    struct tcp_pcb *lists[4] = { ctx->listen_pcbs, ctx->bound_pcbs, ctx->active_pcbs, ctx->tw_pcbs };
-    int i;
+    lists[0] = ctx->listen_pcbs; lists[1] = ctx->bound_pcbs;
+    lists[2] = ctx->active_pcbs; lists[3] = ctx->tw_pcbs;
     for (i = 0; i < 4; i++) {
         struct tcp_pcb *cpcb;
         for (cpcb = lists[i]; cpcb != NULL; cpcb = cpcb->next) {