docs: record v1.1.1 dirty-network recovery design

App/tcp_client.c

@@ -20,6 +20,7 @@ typedef struct {
     struct pbuf *hold_pbuf;
     uint16_t hold_offset;
     uint32_t next_retry_ms;
+    uint32_t connect_start_ms;
     uint8_t index;
     tcp_client_instance_config_t config;
     tcp_client_status_t status;
@@ -37,6 +38,11 @@ static uint16_t ring_used(uint16_t head, uint16_t tail, uint16_t size)
     return (head >= tail) ? (uint16_t)(head - tail) : (uint16_t)(size - tail + head);
 }
 
+static bool tick_reached(uint32_t now, uint32_t deadline)
+{
+    return ((int32_t)(now - deadline) >= 0);
+}
+
 static void tcp_client_reset_rx_state(tcp_client_ctx_t *ctx)
 {
     if (ctx == NULL) {
@@ -51,6 +57,31 @@ static void tcp_client_reset_rx_state(tcp_client_ctx_t *ctx)
     ctx->rx_tail = 0u;
 }
 
+static void tcp_client_abort_connect_timeout(tcp_client_ctx_t *ctx, uint32_t now)
+{
+    if (ctx == NULL) {
+        return;
+    }
+
+    if (ctx->pcb != NULL) {
+        tcp_arg(ctx->pcb, NULL);
+        tcp_recv(ctx->pcb, NULL);
+        tcp_sent(ctx->pcb, NULL);
+        tcp_err(ctx->pcb, NULL);
+        tcp_client_reset_rx_state(ctx);
+        tcp_abort(ctx->pcb);
+        ctx->pcb = NULL;
+    } else {
+        tcp_client_reset_rx_state(ctx);
+    }
+
+    ctx->connect_start_ms = 0u;
+    ctx->status.state = TCP_CLIENT_STATE_DISCONNECTED;
+    ctx->status.errors++;
+    ctx->status.connect_timeout_count++;
+    ctx->next_retry_ms = now + ctx->config.reconnect_interval_ms;
+}
+
 static void tcp_client_fill_ring_from_pbuf(tcp_client_ctx_t *ctx)
 {
     struct pbuf *q;
@@ -111,6 +142,7 @@ static err_t tcp_client_on_recv(void *arg, struct tcp_pcb *pcb, struct pbuf *p,
         tcp_err(pcb, NULL);
         tcp_abort(pcb);
         ctx->pcb = NULL;
+        ctx->connect_start_ms = 0u;
         ctx->status.state = TCP_CLIENT_STATE_DISCONNECTED;
         ctx->next_retry_ms = HAL_GetTick() + ctx->config.reconnect_interval_ms;
         return ERR_ABRT;
@@ -147,6 +179,7 @@ static void tcp_client_on_err(void *arg, err_t err)
     }
     tcp_client_reset_rx_state(ctx);
     ctx->pcb = NULL;
+    ctx->connect_start_ms = 0u;
     ctx->status.state = TCP_CLIENT_STATE_DISCONNECTED;
     ctx->status.errors++;
     ctx->next_retry_ms = HAL_GetTick() + ctx->config.reconnect_interval_ms;
@@ -162,6 +195,7 @@ static err_t tcp_client_on_connected(void *arg, struct tcp_pcb *pcb, err_t err)
     }
     if (err != ERR_OK) {
         ctx->pcb = NULL;
+        ctx->connect_start_ms = 0u;
         ctx->status.state = TCP_CLIENT_STATE_DISCONNECTED;
         ctx->status.errors++;
         ctx->next_retry_ms = HAL_GetTick() + ctx->config.reconnect_interval_ms;
@@ -169,6 +203,7 @@ static err_t tcp_client_on_connected(void *arg, struct tcp_pcb *pcb, err_t err)
     }
 
     ctx->pcb = pcb;
+    ctx->connect_start_ms = 0u;
     ctx->status.state = TCP_CLIENT_STATE_CONNECTED;
     tcp_nagle_disable(pcb);
     tcp_arg(pcb, ctx);
@@ -228,6 +263,7 @@ int tcp_client_connect(uint8_t instance)
         if (err != ERR_OK) {
             tcp_abort(pcb);
             ctx->status.state = TCP_CLIENT_STATE_DISCONNECTED;
+            ctx->connect_start_ms = 0u;
             ctx->status.errors++;
             ctx->next_retry_ms = HAL_GetTick() + ctx->config.reconnect_interval_ms;
             return -1;
@@ -241,6 +277,7 @@ int tcp_client_connect(uint8_t instance)
              ctx->config.remote_ip[3]);
 
     ctx->status.state = TCP_CLIENT_STATE_CONNECTING;
+    ctx->connect_start_ms = HAL_GetTick();
     tcp_arg(pcb, ctx);
     tcp_err(pcb, tcp_client_on_err);
     err = tcp_connect(pcb, &remote_addr, ctx->config.remote_port, tcp_client_on_connected);
@@ -248,6 +285,7 @@ int tcp_client_connect(uint8_t instance)
         tcp_err(pcb, NULL);
         tcp_abort(pcb);
         ctx->status.state = TCP_CLIENT_STATE_DISCONNECTED;
+        ctx->connect_start_ms = 0u;
         ctx->status.errors++;
         ctx->next_retry_ms = HAL_GetTick() + ctx->config.reconnect_interval_ms;
         return -1;
@@ -274,6 +312,7 @@ int tcp_client_disconnect(uint8_t instance)
         tcp_abort(ctx->pcb);
         ctx->pcb = NULL;
     }
+    ctx->connect_start_ms = 0u;
     ctx->status.state = TCP_CLIENT_STATE_DISCONNECTED;
     tcp_client_reset_rx_state(ctx);
     return 0;
@@ -368,21 +407,26 @@ uint16_t tcp_client_peek(uint8_t instance, uint8_t *data, uint16_t max_len)
 void tcp_client_drop(uint8_t instance, uint16_t len)
 {
     tcp_client_ctx_t *ctx;
-    uint16_t dropped = 0u;
+    uint16_t acked = 0u;
 
     if (instance >= TCP_CLIENT_INSTANCE_COUNT || len == 0u) {
         return;
     }
 
     ctx = &g_clients[instance];
-    while (dropped < len && ctx->rx_tail != ctx->rx_head) {
+    while (acked < len) {
-        ctx->rx_tail = (uint16_t)((ctx->rx_tail + 1u) % TCP_CLIENT_RX_BUFFER_SIZE);
-        dropped++;
-    }
-    if (dropped > 0u && ctx->pcb != NULL) {
-        tcp_recved(ctx->pcb, dropped);
-    }
         tcp_client_fill_ring_from_pbuf(ctx);
+        if (ctx->rx_tail == ctx->rx_head) {
+            break;
+        }
+        while (acked < len && ctx->rx_tail != ctx->rx_head) {
+            ctx->rx_tail = (uint16_t)((ctx->rx_tail + 1u) % TCP_CLIENT_RX_BUFFER_SIZE);
+            acked++;
+        }
+    }
+    if (acked > 0u && ctx->pcb != NULL) {
+        tcp_recved(ctx->pcb, acked);
+    }
 }
 
 bool tcp_client_is_connected(uint8_t instance)
@@ -410,9 +454,12 @@ void tcp_client_poll(void)
             continue;
         }
         if ((ctx->pcb != NULL) && (ctx->status.state == TCP_CLIENT_STATE_CONNECTING)) {
+            if ((uint32_t)(now - ctx->connect_start_ms) >= TCP_CLIENT_CONNECT_TIMEOUT_MS) {
+                tcp_client_abort_connect_timeout(ctx, now);
+            }
             continue;
         }
-        if (now >= ctx->next_retry_ms) {
+        if (tick_reached(now, ctx->next_retry_ms)) {
             ctx->status.reconnect_count++;
             ctx->next_retry_ms = now + ctx->config.reconnect_interval_ms;
             (void)tcp_client_connect(i);

App/tcp_client.h

@@ -16,6 +16,7 @@ extern "C" {
 #define TCP_CLIENT_INSTANCE_COUNT      2u
 #define TCP_CLIENT_RX_BUFFER_SIZE      480u
 #define TCP_CLIENT_RECONNECT_DELAY_MS  3000u
+#define TCP_CLIENT_CONNECT_TIMEOUT_MS  10000u
 
 typedef enum {
     TCP_CLIENT_STATE_IDLE = 0,
@@ -39,6 +40,7 @@ typedef struct {
     uint32_t rx_bytes;
     uint32_t tx_bytes;
     uint32_t reconnect_count;
+    uint32_t connect_timeout_count;
     uint32_t errors;
 } tcp_client_status_t;
 

Core/Src/main.c

@@ -149,6 +149,19 @@ static void BootDiag_ReportCh390(void)
                       cfg->net.mask[0], cfg->net.mask[1], cfg->net.mask[2], cfg->net.mask[3],
                       cfg->net.gw[0], cfg->net.gw[1], cfg->net.gw[2], cfg->net.gw[3],
                       cfg->mux_mode);
+    SEGGER_RTT_printf(0,
+                      "ETH rx ok=%u drop=%u pbuf_fail=%u filt=%u ipv6=%u udp=%u igmp=%u lldp=%u other_eth=%u other_ipv4=%u last=0x%04X\r\n",
+                      (unsigned int)diag.rx_packets_ok,
+                      (unsigned int)diag.rx_packets_drop,
+                      (unsigned int)diag.rx_pbuf_alloc_failed,
+                      (unsigned int)diag.rx_filtered_frames,
+                      (unsigned int)diag.rx_filtered_ipv6,
+                      (unsigned int)diag.rx_filtered_udp,
+                      (unsigned int)diag.rx_filtered_igmp,
+                      (unsigned int)diag.rx_filtered_lldp,
+                      (unsigned int)diag.rx_filtered_other_eth,
+                      (unsigned int)diag.rx_filtered_other_ipv4,
+                      diag.last_eth_type);
 }
 
 static void App_ConfigureLinks(const device_config_t *cfg)

Drivers/CH390/ch390_runtime.c

@@ -22,12 +22,19 @@ static uint8_t ch390_runtime_drain_rx(struct netif *netif, uint8_t max_frames)
 {
     struct pbuf *p;
     uint8_t drained = 0u;
+    uint8_t rx_ready;
 
     while (drained < max_frames) {
         p = ch390_runtime_input_frame(netif);
         if (p == NULL) {
+            ch390_read_reg(CH390_MRCMDX);
+            rx_ready = ch390_read_reg(CH390_MRCMDX);
+            if ((rx_ready & CH390_PKT_RDY) == 0u) {
                 break;
             }
+            drained++;
+            continue;
+        }
         ch390_runtime_dispatch_frame(netif, p);
         drained++;
     }
@@ -49,7 +56,179 @@ static uint8_t g_link_restart_pending;
 #define HEALTH_FAIL_SHIFT             4u
 #define HEALTH_FAIL_MASK              0xF0u
 
+#define CH390_RX_FILTER_ENABLE             1u
+#define CH390_RX_PREFIX_LEN                38u
+#define CH390_ETH_HEADER_LEN               14u
+#define CH390_IPV4_MIN_HEADER_LEN          20u
+#define CH390_ETH_TYPE_IPV4                0x0800u
+#define CH390_ETH_TYPE_ARP                 0x0806u
+#define CH390_ETH_TYPE_VLAN                0x8100u
+#define CH390_ETH_TYPE_IPV6                0x86DDu
+#define CH390_ETH_TYPE_QINQ                0x88A8u
+#define CH390_ETH_TYPE_LLDP                0x88CCu
+#define CH390_IP_PROTO_ICMP                1u
+#define CH390_IP_PROTO_IGMP                2u
+#define CH390_IP_PROTO_TCP                 6u
+#define CH390_IP_PROTO_UDP                 17u
+
+typedef enum {
+    CH390_RX_ACCEPT = 0,
+    CH390_RX_DROP_MALFORMED,
+    CH390_RX_DROP_IPV6,
+    CH390_RX_DROP_LLDP,
+    CH390_RX_DROP_UDP,
+    CH390_RX_DROP_IGMP,
+    CH390_RX_DROP_OTHER_ETH,
+    CH390_RX_DROP_OTHER_IPV4
+} ch390_rx_filter_result_t;
+
 static bool ch390_mac_address_valid(const uint8_t *mac);
+static ch390_rx_filter_result_t ch390_runtime_filter_frame(const uint8_t *prefix, uint16_t frame_len, uint16_t prefix_len);
+static void ch390_runtime_count_filtered_frame(ch390_rx_filter_result_t result);
+static void ch390_runtime_copy_prefix_to_pbuf(struct pbuf *p, const uint8_t *prefix, uint16_t prefix_len);
+static void ch390_runtime_read_remaining_to_pbuf(struct pbuf *p, uint16_t offset);
+
+static ch390_rx_filter_result_t ch390_runtime_filter_frame(const uint8_t *prefix, uint16_t frame_len, uint16_t prefix_len)
+{
+    uint16_t eth_type;
+    uint16_t l2_header_len = CH390_ETH_HEADER_LEN;
+    uint16_t ip_offset;
+    uint8_t ip_version;
+    uint8_t ip_ihl;
+    uint8_t ip_proto;
+
+    if ((prefix == NULL) || (frame_len < CH390_ETH_HEADER_LEN) || (prefix_len < CH390_ETH_HEADER_LEN)) {
+        return CH390_RX_DROP_MALFORMED;
+    }
+
+    eth_type = (uint16_t)(((uint16_t)prefix[12] << 8) | prefix[13]);
+    g_diag.last_eth_type = eth_type;
+
+    if ((eth_type == CH390_ETH_TYPE_VLAN) || (eth_type == CH390_ETH_TYPE_QINQ)) {
+        if ((frame_len < (CH390_ETH_HEADER_LEN + 4u)) || (prefix_len < (CH390_ETH_HEADER_LEN + 4u))) {
+            return CH390_RX_DROP_MALFORMED;
+        }
+        l2_header_len = (uint16_t)(CH390_ETH_HEADER_LEN + 4u);
+        eth_type = (uint16_t)(((uint16_t)prefix[16] << 8) | prefix[17]);
+        g_diag.last_eth_type = eth_type;
+    }
+
+    if (eth_type == CH390_ETH_TYPE_ARP) {
+        g_diag.rx_arp_frames++;
+        return CH390_RX_ACCEPT;
+    }
+
+    if (eth_type == CH390_ETH_TYPE_IPV6) {
+        return CH390_RX_DROP_IPV6;
+    }
+
+    if (eth_type == CH390_ETH_TYPE_LLDP) {
+        return CH390_RX_DROP_LLDP;
+    }
+
+    if (eth_type != CH390_ETH_TYPE_IPV4) {
+        return CH390_RX_DROP_OTHER_ETH;
+    }
+
+    ip_offset = l2_header_len;
+    if ((frame_len < (uint16_t)(ip_offset + CH390_IPV4_MIN_HEADER_LEN)) ||
+        (prefix_len < (uint16_t)(ip_offset + CH390_IPV4_MIN_HEADER_LEN))) {
+        return CH390_RX_DROP_MALFORMED;
+    }
+
+    ip_version = (uint8_t)(prefix[ip_offset] >> 4);
+    ip_ihl = (uint8_t)(prefix[ip_offset] & 0x0Fu);
+    if ((ip_version != 4u) || (ip_ihl < 5u)) {
+        return CH390_RX_DROP_MALFORMED;
+    }
+
+    ip_proto = prefix[ip_offset + 9u];
+    g_diag.rx_ip_frames++;
+
+    if (ip_proto == CH390_IP_PROTO_ICMP) {
+        g_diag.rx_ipv4_icmp_frames++;
+        return CH390_RX_ACCEPT;
+    }
+
+    if (ip_proto == CH390_IP_PROTO_TCP) {
+        g_diag.rx_ipv4_tcp_frames++;
+        return CH390_RX_ACCEPT;
+    }
+
+    if (ip_proto == CH390_IP_PROTO_UDP) {
+        g_diag.rx_ipv4_udp_frames++;
+        return CH390_RX_DROP_UDP;
+    }
+
+    if (ip_proto == CH390_IP_PROTO_IGMP) {
+        g_diag.rx_filtered_igmp++;
+        return CH390_RX_DROP_IGMP;
+    }
+
+    return CH390_RX_DROP_OTHER_IPV4;
+}
+
+static void ch390_runtime_count_filtered_frame(ch390_rx_filter_result_t result)
+{
+    g_diag.rx_filtered_frames++;
+    switch (result) {
+    case CH390_RX_DROP_MALFORMED:
+        g_diag.rx_filtered_malformed++;
+        break;
+    case CH390_RX_DROP_IPV6:
+        g_diag.rx_filtered_ipv6++;
+        break;
+    case CH390_RX_DROP_LLDP:
+        g_diag.rx_filtered_lldp++;
+        break;
+    case CH390_RX_DROP_UDP:
+        g_diag.rx_filtered_udp++;
+        break;
+    case CH390_RX_DROP_IGMP:
+        break;
+    case CH390_RX_DROP_OTHER_ETH:
+        g_diag.rx_filtered_other_eth++;
+        break;
+    case CH390_RX_DROP_OTHER_IPV4:
+        g_diag.rx_filtered_other_ipv4++;
+        break;
+    case CH390_RX_ACCEPT:
+    default:
+        break;
+    }
+}
+
+static void ch390_runtime_copy_prefix_to_pbuf(struct pbuf *p, const uint8_t *prefix, uint16_t prefix_len)
+{
+    struct pbuf *q;
+    uint16_t copied = 0u;
+
+    for (q = p; (q != NULL) && (copied < prefix_len); q = q->next) {
+        uint16_t chunk = (uint16_t)(prefix_len - copied);
+        if (chunk > q->len) {
+            chunk = q->len;
+        }
+        memcpy(q->payload, &prefix[copied], chunk);
+        copied = (uint16_t)(copied + chunk);
+    }
+}
+
+static void ch390_runtime_read_remaining_to_pbuf(struct pbuf *p, uint16_t offset)
+{
+    struct pbuf *q;
+    uint16_t skipped = 0u;
+
+    for (q = p; q != NULL; q = q->next) {
+        if (skipped >= offset) {
+            ch390_read_mem((uint8_t *)q->payload, q->len);
+        } else if ((uint16_t)(skipped + q->len) > offset) {
+            uint16_t in_chunk_offset = (uint16_t)(offset - skipped);
+            uint16_t read_len = (uint16_t)(q->len - in_chunk_offset);
+            ch390_read_mem(&((uint8_t *)q->payload)[in_chunk_offset], read_len);
+        }
+        skipped = (uint16_t)(skipped + q->len);
+    }
+}
 
 static uint8_t ch390_runtime_is_restart_pending(void)
 {
@@ -154,12 +333,14 @@ struct pbuf *ch390_runtime_input_frame(struct netif *netif)
 {
     struct ethernetif *ethernetif = (struct ethernetif *)netif->state;
     struct pbuf *p = NULL;
-    struct pbuf *q;
     uint16_t len;
     uint16_t frame_len;
+    uint16_t prefix_len;
     uint8_t rcr;
     uint8_t rx_ready;
     uint8_t rx_header[4];
+    uint8_t frame_prefix[CH390_RX_PREFIX_LEN];
+    ch390_rx_filter_result_t filter_result;
     ch390_read_reg(CH390_MRCMDX);
     rx_ready = ch390_read_reg(CH390_MRCMDX);
 
@@ -196,6 +377,23 @@ struct pbuf *ch390_runtime_input_frame(struct netif *netif)
     }
 
     ethernetif->rx_len = frame_len;
+    prefix_len = frame_len;
+    if (prefix_len > CH390_RX_PREFIX_LEN) {
+        prefix_len = CH390_RX_PREFIX_LEN;
+    }
+    ch390_read_mem(frame_prefix, prefix_len);
+
+#if CH390_RX_FILTER_ENABLE
+    filter_result = ch390_runtime_filter_frame(frame_prefix, frame_len, prefix_len);
+    if (filter_result != CH390_RX_ACCEPT) {
+        ch390_drop_packet((uint16_t)(frame_len - prefix_len));
+        LINK_STATS_INC(link.drop);
+        g_diag.rx_packets_drop++;
+        ch390_runtime_count_filtered_frame(filter_result);
+        return NULL;
+    }
+#endif
+
     len = ethernetif->rx_len;
 #if ETH_PAD_SIZE
     len += ETH_PAD_SIZE;
@@ -206,9 +404,8 @@ struct pbuf *ch390_runtime_input_frame(struct netif *netif)
 #if ETH_PAD_SIZE
         pbuf_remove_header(p, ETH_PAD_SIZE);
 #endif
-        for (q = p; q != NULL; q = q->next) {
+        ch390_runtime_copy_prefix_to_pbuf(p, frame_prefix, prefix_len);
-            ch390_read_mem((uint8_t *)q->payload, q->len);
+        ch390_runtime_read_remaining_to_pbuf(p, prefix_len);
-        }
 #if ETH_PAD_SIZE
         pbuf_add_header(p, ETH_PAD_SIZE);
 #endif
@@ -218,10 +415,11 @@ struct pbuf *ch390_runtime_input_frame(struct netif *netif)
         g_diag.last_frame_len = frame_len;
         g_diag.last_payload_len = p->tot_len;
     } else {
-        ch390_drop_packet(ethernetif->rx_len);
+        ch390_drop_packet((uint16_t)(frame_len - prefix_len));
         LINK_STATS_INC(link.memerr);
         LINK_STATS_INC(link.drop);
         g_diag.rx_packets_drop++;
+        g_diag.rx_pbuf_alloc_failed++;
     }
 
     return p;

Drivers/CH390/ch390_runtime.h

@@ -38,8 +38,20 @@ typedef struct {
     uint32_t rx_packets_drop;
     uint32_t tx_packets_ok;
     uint32_t tx_packets_timeout;
+    uint32_t rx_pbuf_alloc_failed;
+    uint32_t rx_filtered_frames;
+    uint32_t rx_filtered_ipv6;
+    uint32_t rx_filtered_udp;
+    uint32_t rx_filtered_igmp;
+    uint32_t rx_filtered_lldp;
+    uint32_t rx_filtered_other_eth;
+    uint32_t rx_filtered_other_ipv4;
+    uint32_t rx_filtered_malformed;
     uint32_t rx_arp_frames;
     uint32_t rx_ip_frames;
+    uint32_t rx_ipv4_icmp_frames;
+    uint32_t rx_ipv4_tcp_frames;
+    uint32_t rx_ipv4_udp_frames;
     uint32_t rx_other_frames;
     uint32_t rx_unicast_self_frames;
     uint32_t rx_broadcast_frames;

MDK-ARM/keil-build-viewer-record.txt

@@ -1,7 +1,7 @@
       Code (inc. data)   RO Data    RW Data    ZI Data      Debug   Object Name
        632          0          0          0          0          0   ch390.o
        616          0         64          0          0          0   ch390_interface.o
-      2050          0         85          6         88          0   ch390_runtime.o
+      2546          0         85          6        136          0   ch390_runtime.o
       3958          0        591          8       1240          0   config.o
          8          0          0          0          0          0   def.o
        124          0          0          0          0          0   dma.o
@@ -17,7 +17,7 @@
        778          0          0          2          0          0   ip4.o
         46          0          4          0          0          0   ip4_addr.o
         44          0          0          0         12          0   iwdg.o
-      3212          0        185         12        272          0   main.o
+      3264          0        300         12        272          0   main.o
        828          0          0         12       4115          0   mem.o
        196          0        244         32       6464          0   memp.o
        582          0          0         12          0          0   netif.o
@@ -43,10 +43,10 @@
        490          0          0          0          0          0   stm32f1xx_it.o
          2          0         24          4          0          0   system_stm32f1xx.o
       3474          0        193         32          0          0   tcp.o
-      1556          0          0          0       1072          0   tcp_client.o
+      1734          0          0          0       1088          0   tcp_client.o
       3684          0          0         36         20          0   tcp_in.o
       3862          0          0          0          0          0   tcp_out.o
-      1346          0          0          0       1048          0   tcp_server.o
+      1364          0          0          0       1048          0   tcp_server.o
        164          0          0          0         72          0   tim.o
        374          0         16         12          0          0   timeouts.o
       1590          0          0          0       2936          0   uart_trans.o
@@ -57,8 +57,8 @@ Memory Map of the image
 
 	Load Region LR_IROM1 
 
-		Execution Region ER_IROM1 (Exec base: 0x08000000, Size: 0x0000DB7C, Max: 0x00010000, END)
+		Execution Region ER_IROM1 (Exec base: 0x08000000, Size: 0x0000DED8, Max: 0x00010000, END)
 
-		Execution Region RW_IRAM1 (Exec base: 0x20000000, Size: 0x00004F98, Max: 0x00005000, END)
+		Execution Region RW_IRAM1 (Exec base: 0x20000000, Size: 0x00004FD8, Max: 0x00005000, END)
 
 Image component sizes

项目技术实现.md

@@ -246,6 +246,55 @@ EN,LPORT,RIP,RPORT,UART
 
 该结果说明修复后工程仍满足 `STM32F103R8T6` 的 `20KB RAM` 上限，但余量已经很小；后续若继续增加功能，应优先考虑复用现有缓冲与状态，而不是增加新的静态大数组。
 
+### 6.3 客户现场脏网络恢复增强
+
+客户现场换 PC 后曾出现设备持续 ARP、`ping` 不通、TCP Client 不恢复的现象。抓包显示故障前后存在 IPv6、DHCPv6、mDNS、IGMP、LLDP 等与当前业务无关的网络噪声；当前固件为静态 IPv4、TCP2UART 与 ICMP 诊断模型，不依赖 UDP、IPv6、DHCP 或多播发现。
+
+本阶段采用低 RAM 优先的恢复策略，不先扩大 `PBUF_POOL_SIZE`，而是在更靠近入口的位置减少无关帧对 lwIP pool 的占用：
+
+1. `TCP Client CONNECTING` 增加应用层超时：
+   - `TCP_CLIENT_CONNECT_TIMEOUT_MS = 10000`
+   - `tcp_connect()` 返回 `ERR_OK` 后记录 `connect_start_ms`
+   - `tcp_client_poll()` 发现 `CONNECTING` 超过超时时间后，注销回调、`tcp_abort()` 当前 PCB、释放 `hold_pbuf`，再按原有 `reconnect_interval_ms` 重连
+   - `tcp_client_status_t.connect_timeout_count` 记录发生次数
+2. `CH390` RX 入口增加 `pre-pbuf` 协议过滤：
+   - 在 `pbuf_alloc(PBUF_RAW, ..., PBUF_POOL)` 之前先读取以太网头与最小 IPv4 头
+   - 允许进入 lwIP 的协议限定为 `ARP`、`IPv4 ICMP`、`IPv4 TCP`
+   - 默认丢弃 `IPv6`、`IPv4 UDP`、`IPv4 IGMP`、`LLDP`、未知 EtherType 与畸形头
+   - 丢弃帧只跳过 CH390 RX FIFO 剩余字节，不分配 pbuf
+3. 软件 MAC 过滤暂不启用：
+   - 第一版只做协议层过滤，避免误杀广播 ARP 或未来硬件过滤策略变化
+   - 目的 MAC 相关判断保留为后续可选增强
+
+新增 CH390 诊断字段用于现场判断是否仍存在资源压力：
+
+1. `rx_pbuf_alloc_failed`
+2. `rx_filtered_frames`
+3. `rx_filtered_ipv6`
+4. `rx_filtered_udp`
+5. `rx_filtered_igmp`
+6. `rx_filtered_lldp`
+7. `rx_filtered_other_eth`
+8. `rx_filtered_other_ipv4`
+9. `rx_filtered_malformed`
+10. `rx_ipv4_icmp_frames`
+11. `rx_ipv4_tcp_frames`
+12. `rx_ipv4_udp_frames`
+
+验收口径：
+
+1. 正常 `ARP / ping / TCP Server / TCP Client` 功能不受影响
+2. 客户脏网络中的 IPv6、UDP、IGMP、LLDP 噪声不会进入 lwIP pbuf pool
+3. 若远端 TCP Server 不监听或静默丢 SYN，TCP Client 不再永久停留在 `CONNECTING`
+4. 若过滤后 `rx_pbuf_alloc_failed` 仍持续增长，再评估从无关功能中回收 RAM 并调整 `PBUF_POOL_SIZE`
+
+本阶段 Keil 构建验收结果：
+
+1. `errors = 0`
+2. `warnings = 0`
+3. `flash_bytes = 57404`
+4. `ram_bytes = 20440`
+
 ## 七、主循环实现方向
 
 主循环仍保持裸机轮询风格：