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Fix win32 packet capture local #70

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Merged
dosshell merged 1 commit into from
Oct 29, 2026
Merged

Fix win32 packet capture local #70

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64 changes: 27 additions & 37 deletions include/tinycsocket.h
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Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,7 @@
#ifndef TINYCSOCKET_INTERNAL_H_
#define TINYCSOCKET_INTERNAL_H_

static const char* const TCS_VERSION_TXT = "v0.3.85";
static const char* const TCS_VERSION_TXT = "v0.3.86";
extern const char* const TCS_LICENSE_TXT;

/*
Expand Down Expand Up @@ -4913,15 +4913,11 @@ static bool (*tcs_internal_packet_address_is_supported_impl)(const struct TcsAdd
// the Npcap SDK is needed at build time: the few pcap types and functions used are declared here, and their ABI has
// been frozen since WinPcap.
//
// Supported: Npcap 1.00 (2020) or later, the first stable release. Every function resolved by
// tcs_internal_lib_init_impl_npcap() exists in all Npcap releases, since Npcap has always shipped a libpcap newer than 1.5.
// pcap_set_immediate_mode() is what rules out WinPcap and Win10Pcap, which stop at libpcap 1.0; a fallback to
// pcap_setmintocopy(p, 0) would admit them. Behaviour that depends on the version: 802.1Q tags are restored on
// receive from Npcap 1.81 (fixed for TCI 0 in 1.82 and for stacked tags in 1.88). Before that, NDIS has already
// stripped the tag, so tagged frames arrive untagged. The filter in tcs_internal_npcap_socket_filter() matches both cases.
// Please be aware of npcap license issues.
//
// Not supported: Wine. Its builtin wpcap.dll forwards to the host libpcap, but pcap_getevent() is a stub that raises
// an exception, so tcs_internal_lib_init_impl_npcap() leaves packet sockets unsupported when it detects Wine.
// Supported: Npcap 1.00 (2020) or later.
//
// Wine is shipped with a custom npcap implementation that is currently not supported, a WaitForSingleObject workaround is needed.

typedef struct pcap pcap_t;

Expand All @@ -4945,9 +4941,13 @@ struct bpf_program
#define TCS_PCAP_ERROR_PERM_DENIED (-8)
#define TCS_PCAP_ERROR_IFACE_NOT_UP (-9)
#define TCS_PCAP_ERROR_PROMISC_PERM_DENIED (-11)
#define TCS_PCAP_OPENFLAG_PROMISCUOUS 1
#define TCS_PCAP_OPENFLAG_NOCAPTURE_LOCAL 8
#define TCS_PCAP_OPENFLAG_MAX_RESPONSIVENESS 16

typedef pcap_t*(__cdecl* TcsInternalPcapCreate)(const char*, char*);
typedef int(__cdecl* TcsInternalPcapSetInt)(pcap_t*, int);
struct pcap_rmtauth; // Only ever passed as NULL
typedef pcap_t*(__cdecl* TcsInternalPcapOpen)(const char*, int, int, int, struct pcap_rmtauth*, char*);
typedef const char*(__cdecl* TcsInternalPcapStatusToStr)(int);
typedef int(__cdecl* TcsInternalPcapGetInt)(pcap_t*);
typedef int(__cdecl* TcsInternalPcapSetNonblock)(pcap_t*, int, char*);
typedef HANDLE(__cdecl* TcsInternalPcapGetEvent)(pcap_t*);
Expand Down Expand Up @@ -4977,13 +4977,10 @@ struct TcsInternalNpcapSocket

static struct
{
HMODULE module; // NULL when Npcap is not installed or the library is not initialized
int init_count; // tcs_lib_init() calls not yet matched by tcs_lib_cleanup()
TcsInternalPcapCreate create;
TcsInternalPcapSetInt set_snaplen;
TcsInternalPcapSetInt set_promisc;
TcsInternalPcapSetInt set_immediate_mode;
TcsInternalPcapGetInt activate;
HMODULE module;
int init_count;
TcsInternalPcapOpen open;
TcsInternalPcapStatusToStr statustostr;
TcsInternalPcapGetInt datalink;
TcsInternalPcapSetNonblock setnonblock;
TcsInternalPcapGetEvent getevent;
Expand Down Expand Up @@ -5083,22 +5080,19 @@ static TcsResult tcs_internal_npcap_socket_open(struct TcsInternalNpcapSocket* p
if (!found)
return TCS_ERROR_INVALID_ARGUMENT;

char errbuf[TCS_PCAP_ERRBUF_SIZE];
pcap_t* pcap = g_npcap.create(device, errbuf);
int flags = TCS_PCAP_OPENFLAG_NOCAPTURE_LOCAL | TCS_PCAP_OPENFLAG_MAX_RESPONSIVENESS;
if (ps->group_count > 0)
flags |= TCS_PCAP_OPENFLAG_PROMISCUOUS;
char errbuf[TCS_PCAP_ERRBUF_SIZE] = "";
pcap_t* pcap = g_npcap.open(device, 65535, flags, 0, NULL, errbuf);
if (pcap == NULL)
return TCS_ERROR_SYSTEM;
g_npcap.set_snaplen(pcap, 65535);
g_npcap.set_promisc(pcap, ps->group_count > 0);
g_npcap.set_immediate_mode(pcap, 1); // Deliver every frame at once instead of batching them in the driver
int activate_sts = g_npcap.activate(pcap);
if (activate_sts < 0)
{
g_npcap.close(pcap);
if (activate_sts == TCS_PCAP_ERROR_PERM_DENIED || activate_sts == TCS_PCAP_ERROR_PROMISC_PERM_DENIED)
if (strstr(errbuf, g_npcap.statustostr(TCS_PCAP_ERROR_PERM_DENIED)) != NULL ||
strstr(errbuf, g_npcap.statustostr(TCS_PCAP_ERROR_PROMISC_PERM_DENIED)) != NULL)
return TCS_ERROR_PERMISSION_DENIED;
if (activate_sts == TCS_PCAP_ERROR_NO_SUCH_DEVICE)
if (strstr(errbuf, g_npcap.statustostr(TCS_PCAP_ERROR_NO_SUCH_DEVICE)) != NULL)
return TCS_ERROR_INVALID_ARGUMENT;
if (activate_sts == TCS_PCAP_ERROR_IFACE_NOT_UP)
if (strstr(errbuf, g_npcap.statustostr(TCS_PCAP_ERROR_IFACE_NOT_UP)) != NULL)
return TCS_ERROR_NETWORK_UNREACHABLE;
return TCS_ERROR_SYSTEM;
}
Expand Down Expand Up @@ -5504,11 +5498,8 @@ static void tcs_internal_lib_init_impl_npcap(void)
return;

// FARPROC is cast through void (*)(void), which gcc treats as compatible with every function pointer type
g_npcap.create = (TcsInternalPcapCreate)(void (*)(void))GetProcAddress(m, "pcap_create");
g_npcap.set_snaplen = (TcsInternalPcapSetInt)(void (*)(void))GetProcAddress(m, "pcap_set_snaplen");
g_npcap.set_promisc = (TcsInternalPcapSetInt)(void (*)(void))GetProcAddress(m, "pcap_set_promisc");
g_npcap.set_immediate_mode = (TcsInternalPcapSetInt)(void (*)(void))GetProcAddress(m, "pcap_set_immediate_mode");
g_npcap.activate = (TcsInternalPcapGetInt)(void (*)(void))GetProcAddress(m, "pcap_activate");
g_npcap.open = (TcsInternalPcapOpen)(void (*)(void))GetProcAddress(m, "pcap_open");
g_npcap.statustostr = (TcsInternalPcapStatusToStr)(void (*)(void))GetProcAddress(m, "pcap_statustostr");
g_npcap.datalink = (TcsInternalPcapGetInt)(void (*)(void))GetProcAddress(m, "pcap_datalink");
g_npcap.setnonblock = (TcsInternalPcapSetNonblock)(void (*)(void))GetProcAddress(m, "pcap_setnonblock");
g_npcap.getevent = (TcsInternalPcapGetEvent)(void (*)(void))GetProcAddress(m, "pcap_getevent");
Expand All @@ -5519,8 +5510,7 @@ static void tcs_internal_lib_init_impl_npcap(void)
g_npcap.sendpacket = (TcsInternalPcapSendPacket)(void (*)(void))GetProcAddress(m, "pcap_sendpacket");
g_npcap.close = (TcsInternalPcapClose)(void (*)(void))GetProcAddress(m, "pcap_close");

if (g_npcap.create == NULL || g_npcap.set_snaplen == NULL || g_npcap.set_promisc == NULL ||
g_npcap.set_immediate_mode == NULL || g_npcap.activate == NULL || g_npcap.datalink == NULL ||
if (g_npcap.open == NULL || g_npcap.statustostr == NULL || g_npcap.datalink == NULL ||
g_npcap.setnonblock == NULL || g_npcap.getevent == NULL || g_npcap.compile == NULL ||
g_npcap.setfilter == NULL || g_npcap.freecode == NULL || g_npcap.next_ex == NULL ||
g_npcap.sendpacket == NULL || g_npcap.close == NULL)
Expand Down
2 changes: 1 addition & 1 deletion src/tinycsocket_internal.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@
#ifndef TINYCSOCKET_INTERNAL_H_
#define TINYCSOCKET_INTERNAL_H_

static const char* const TCS_VERSION_TXT = "v0.3.85";
static const char* const TCS_VERSION_TXT = "v0.3.86";
extern const char* const TCS_LICENSE_TXT;

/*
Expand Down
62 changes: 26 additions & 36 deletions src/tinycsocket_win32.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -535,15 +535,11 @@ static bool (*tcs_internal_packet_address_is_supported_impl)(const struct TcsAdd
// the Npcap SDK is needed at build time: the few pcap types and functions used are declared here, and their ABI has
// been frozen since WinPcap.
//
// Supported: Npcap 1.00 (2020) or later, the first stable release. Every function resolved by
// tcs_internal_lib_init_impl_npcap() exists in all Npcap releases, since Npcap has always shipped a libpcap newer than 1.5.
// pcap_set_immediate_mode() is what rules out WinPcap and Win10Pcap, which stop at libpcap 1.0; a fallback to
// pcap_setmintocopy(p, 0) would admit them. Behaviour that depends on the version: 802.1Q tags are restored on
// receive from Npcap 1.81 (fixed for TCI 0 in 1.82 and for stacked tags in 1.88). Before that, NDIS has already
// stripped the tag, so tagged frames arrive untagged. The filter in tcs_internal_npcap_socket_filter() matches both cases.
// Please be aware of npcap license issues.
//
// Not supported: Wine. Its builtin wpcap.dll forwards to the host libpcap, but pcap_getevent() is a stub that raises
// an exception, so tcs_internal_lib_init_impl_npcap() leaves packet sockets unsupported when it detects Wine.
// Supported: Npcap 1.00 (2020) or later.
//
// Wine is shipped with a custom npcap implementation that is currently not supported, a WaitForSingleObject workaround is needed.

typedef struct pcap pcap_t;

Expand All @@ -567,9 +563,13 @@ struct bpf_program
#define TCS_PCAP_ERROR_PERM_DENIED (-8)
#define TCS_PCAP_ERROR_IFACE_NOT_UP (-9)
#define TCS_PCAP_ERROR_PROMISC_PERM_DENIED (-11)
#define TCS_PCAP_OPENFLAG_PROMISCUOUS 1
#define TCS_PCAP_OPENFLAG_NOCAPTURE_LOCAL 8
#define TCS_PCAP_OPENFLAG_MAX_RESPONSIVENESS 16

typedef pcap_t*(__cdecl* TcsInternalPcapCreate)(const char*, char*);
typedef int(__cdecl* TcsInternalPcapSetInt)(pcap_t*, int);
struct pcap_rmtauth; // Only ever passed as NULL
typedef pcap_t*(__cdecl* TcsInternalPcapOpen)(const char*, int, int, int, struct pcap_rmtauth*, char*);
typedef const char*(__cdecl* TcsInternalPcapStatusToStr)(int);
typedef int(__cdecl* TcsInternalPcapGetInt)(pcap_t*);
typedef int(__cdecl* TcsInternalPcapSetNonblock)(pcap_t*, int, char*);
typedef HANDLE(__cdecl* TcsInternalPcapGetEvent)(pcap_t*);
Expand Down Expand Up @@ -599,13 +599,10 @@ struct TcsInternalNpcapSocket

static struct
{
HMODULE module; // NULL when Npcap is not installed or the library is not initialized
int init_count; // tcs_lib_init() calls not yet matched by tcs_lib_cleanup()
TcsInternalPcapCreate create;
TcsInternalPcapSetInt set_snaplen;
TcsInternalPcapSetInt set_promisc;
TcsInternalPcapSetInt set_immediate_mode;
TcsInternalPcapGetInt activate;
HMODULE module;
int init_count;
TcsInternalPcapOpen open;
TcsInternalPcapStatusToStr statustostr;
TcsInternalPcapGetInt datalink;
TcsInternalPcapSetNonblock setnonblock;
TcsInternalPcapGetEvent getevent;
Expand Down Expand Up @@ -705,22 +702,19 @@ static TcsResult tcs_internal_npcap_socket_open(struct TcsInternalNpcapSocket* p
if (!found)
return TCS_ERROR_INVALID_ARGUMENT;

char errbuf[TCS_PCAP_ERRBUF_SIZE];
pcap_t* pcap = g_npcap.create(device, errbuf);
int flags = TCS_PCAP_OPENFLAG_NOCAPTURE_LOCAL | TCS_PCAP_OPENFLAG_MAX_RESPONSIVENESS;
if (ps->group_count > 0)
flags |= TCS_PCAP_OPENFLAG_PROMISCUOUS;
char errbuf[TCS_PCAP_ERRBUF_SIZE] = "";
pcap_t* pcap = g_npcap.open(device, 65535, flags, 0, NULL, errbuf);
if (pcap == NULL)
return TCS_ERROR_SYSTEM;
g_npcap.set_snaplen(pcap, 65535);
g_npcap.set_promisc(pcap, ps->group_count > 0);
g_npcap.set_immediate_mode(pcap, 1); // Deliver every frame at once instead of batching them in the driver
int activate_sts = g_npcap.activate(pcap);
if (activate_sts < 0)
{
g_npcap.close(pcap);
if (activate_sts == TCS_PCAP_ERROR_PERM_DENIED || activate_sts == TCS_PCAP_ERROR_PROMISC_PERM_DENIED)
if (strstr(errbuf, g_npcap.statustostr(TCS_PCAP_ERROR_PERM_DENIED)) != NULL ||
strstr(errbuf, g_npcap.statustostr(TCS_PCAP_ERROR_PROMISC_PERM_DENIED)) != NULL)
return TCS_ERROR_PERMISSION_DENIED;
if (activate_sts == TCS_PCAP_ERROR_NO_SUCH_DEVICE)
if (strstr(errbuf, g_npcap.statustostr(TCS_PCAP_ERROR_NO_SUCH_DEVICE)) != NULL)
return TCS_ERROR_INVALID_ARGUMENT;
if (activate_sts == TCS_PCAP_ERROR_IFACE_NOT_UP)
if (strstr(errbuf, g_npcap.statustostr(TCS_PCAP_ERROR_IFACE_NOT_UP)) != NULL)
return TCS_ERROR_NETWORK_UNREACHABLE;
return TCS_ERROR_SYSTEM;
}
Expand Down Expand Up @@ -1126,11 +1120,8 @@ static void tcs_internal_lib_init_impl_npcap(void)
return;

// FARPROC is cast through void (*)(void), which gcc treats as compatible with every function pointer type
g_npcap.create = (TcsInternalPcapCreate)(void (*)(void))GetProcAddress(m, "pcap_create");
g_npcap.set_snaplen = (TcsInternalPcapSetInt)(void (*)(void))GetProcAddress(m, "pcap_set_snaplen");
g_npcap.set_promisc = (TcsInternalPcapSetInt)(void (*)(void))GetProcAddress(m, "pcap_set_promisc");
g_npcap.set_immediate_mode = (TcsInternalPcapSetInt)(void (*)(void))GetProcAddress(m, "pcap_set_immediate_mode");
g_npcap.activate = (TcsInternalPcapGetInt)(void (*)(void))GetProcAddress(m, "pcap_activate");
g_npcap.open = (TcsInternalPcapOpen)(void (*)(void))GetProcAddress(m, "pcap_open");
g_npcap.statustostr = (TcsInternalPcapStatusToStr)(void (*)(void))GetProcAddress(m, "pcap_statustostr");
g_npcap.datalink = (TcsInternalPcapGetInt)(void (*)(void))GetProcAddress(m, "pcap_datalink");
g_npcap.setnonblock = (TcsInternalPcapSetNonblock)(void (*)(void))GetProcAddress(m, "pcap_setnonblock");
g_npcap.getevent = (TcsInternalPcapGetEvent)(void (*)(void))GetProcAddress(m, "pcap_getevent");
Expand All @@ -1141,8 +1132,7 @@ static void tcs_internal_lib_init_impl_npcap(void)
g_npcap.sendpacket = (TcsInternalPcapSendPacket)(void (*)(void))GetProcAddress(m, "pcap_sendpacket");
g_npcap.close = (TcsInternalPcapClose)(void (*)(void))GetProcAddress(m, "pcap_close");

if (g_npcap.create == NULL || g_npcap.set_snaplen == NULL || g_npcap.set_promisc == NULL ||
g_npcap.set_immediate_mode == NULL || g_npcap.activate == NULL || g_npcap.datalink == NULL ||
if (g_npcap.open == NULL || g_npcap.statustostr == NULL || g_npcap.datalink == NULL ||
g_npcap.setnonblock == NULL || g_npcap.getevent == NULL || g_npcap.compile == NULL ||
g_npcap.setfilter == NULL || g_npcap.freecode == NULL || g_npcap.next_ex == NULL ||
g_npcap.sendpacket == NULL || g_npcap.close == NULL)
Expand Down
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