Add support for raw + af_packet sockets by danielinux · Pull Request #63 · wolfSSL/wolfip

danielinux · 2026-03-03T17:22:53Z

Add support for raw sockets and packet sockets.

Added support for BSD wrapper in posix systems.
Added 'raw_ping' and 'packet_ping' examples to craft ICMP echo requests / receive replies using the new sockets
Added automated tests to github workflow

Superseeds #10

Add support for raw sockets and packet sockets. - Added support for BSD wrapper in posix systems. - Added 'raw_ping' and 'packet_ping' examples to craft ICMP echo requests / receive replies using the new sockets - Added automated tests to github workflow

Copilot

Pull request overview

Adds raw IP socket and AF_PACKET-style packet socket support to wolfIP, including POSIX preload shim enhancements and new example utilities for pinging via the new socket types.

Changes:

Add RAW and PACKET socket types to the wolfIP socket API, including send/recv/bind/connect/poll support.
Extend the POSIX LD_PRELOAD BSD socket shim with ioctl() handling for interface/ARP queries needed by packet sockets.
Add new raw_ping / packet_ping examples and run them in CI.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
`wolfip.h`	Adds socket constants, socket marks, and `sockaddr_ll` support plus ARP lookup API.
`src/wolfip.c`	Implements raw sockets + packet sockets, routing/ARP for raw TX, and capture paths for RX.
`src/test/unit/unit.c`	Adds unit tests covering raw/packet socket send/recv behaviors.
`src/test/raw_ping.c`	New raw-socket ping example for CI/manual testing.
`src/test/packet_ping.c`	New AF_PACKET ping example using ioctl-derived interface info.
`src/port/posix/bsd_socket.c`	Adds `ioctl()` interception and fd bookkeeping for raw/packet sockets.
`config.h`	Enables raw/packet sockets by default and sets default max counts.
`Makefile`	Builds the new ping example binaries.
`.github/workflows/linux.yml`	Runs `raw_ping` and `packet_ping` under LD_PRELOAD in CI.

Comments suppressed due to low confidence (2)

src/test/raw_ping.c:55

The checksum helper handles odd-length buffers incorrectly: for a trailing byte it should be added as the high-order byte of the final 16-bit word (i.e., byte << 8, zero-padded), not as a low-order byte. This matches how Internet checksums are computed (and how the stack’s checksum helpers handle odd lengths).

    if (len == 1) {
        sum += *(unsigned char *)buf;
    }

src/test/packet_ping.c:99

The checksum helper adds the trailing byte for odd-length buffers without shifting it into the high-order position of the final 16-bit word. For correctness with arbitrary payload sizes, treat the last byte as byte << 8 (zero-padded) when len is odd.

    if (len == 1) {
        sum += *(unsigned char *)buf;
    }

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src/wolfip.c

src/port/posix/bsd_socket.c

src/test/unit/unit.c

config.h

src/wolfip.c

src/test/unit/unit.c

Copilot

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

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src/port/posix/bsd_socket.c

src/wolfip.c

Copilot

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 4 comments.

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.github/workflows/linux.yml

Makefile

src/wolfip.c

src/port/posix/bsd_socket.c

Copilot

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated 10 comments.

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Copilot · 2026-03-03T22:01:38Z

src/port/posix/bsd_socket.c

+    va_list ap;
+    uintptr_t arg;
+    void *argp;
+    struct ifreq *ifr;
+    int i;
+
+    va_start(ap, request);
+    arg = va_arg(ap, uintptr_t);
+    va_end(ap);
+    argp = (void *)arg;
+
+    if (in_the_stack) {
+        return host_ioctl ? host_ioctl(fd, request, arg) : -1;
+    }
+
+    if (request == SIOCGIFINDEX || request == SIOCGIFHWADDR || request == SIOCGIFADDR) {
+        struct wolfip_fd_entry *entry = wolfip_entry_from_public(fd);
+        if (!entry) {


ioctl varargs are read as unsigned long, but callers pass a pointer for requests like SIOCGIFINDEX/SIOCGARP. Reading a pointer argument with the wrong va_arg type is undefined behavior and can break on some ABIs. Read the vararg as void * (or uintptr_t) and forward that same pointer to host_ioctl.

Suggested change

va_list ap;

uintptr_t arg;

void *argp;

struct ifreq *ifr;

int i;

va_start(ap, request);

arg = va_arg(ap, uintptr_t);

va_end(ap);

argp = (void *)arg;

if (in_the_stack) {

return host_ioctl ? host_ioctl(fd, request, arg) : -1;

}

if (request == SIOCGIFINDEX || request == SIOCGIFHWADDR || request == SIOCGIFADDR) {

struct wolfip_fd_entry *entry = wolfip_entry_from_public(fd);

if (!entry) {

void *argp;

struct ifreq *ifr;

int i;

va_start(ap, request);

argp = va_arg(ap, void *);

va_end(ap);

if (in_the_stack) {

return host_ioctl ? host_ioctl(fd, request, argp) : -1;

}

if (request == SIOCGIFINDEX || request == SIOCGIFHWADDR || request == SIOCGIFADDR) {

struct wolfip_fd_entry *entry = wolfip_entry_from_public(fd);

if (!entry) {

return host_ioctl ? host_ioctl(fd, request, argp) : -1;

Copilot · 2026-03-03T22:01:38Z

src/port/posix/bsd_socket.c

+                ret = wolfIP_sock_bind(IPSTACK, internal_fd,
+                        (const struct wolfIP_sockaddr *)addr, addrlen);
+            }
+            if (ret < 0) {


wolfIP APIs return negative error codes (e.g., -WOLFIP_EINVAL). Assigning errno = ret sets errno to a negative value. Set errno to -ret (positive) to match POSIX expectations.

Suggested change

if (ret < 0) {

errno = -ret;

Copilot · 2026-03-03T22:01:38Z

src/port/posix/bsd_socket.c

+                }
+                if (ret != -EAGAIN)
+                    break;
+                if (nonblock) {
+                    errno = EAGAIN;
+                    pthread_mutex_unlock(&wolfIP_mutex);
+                    return -1;


This wrapper mixes host EAGAIN with wolfIP's -WOLFIP_EAGAIN and also assigns errno = ret (negative). Use wolfIP's return convention consistently: compare against -WOLFIP_EAGAIN and set errno to -ret when returning -1.

Copilot · 2026-03-03T22:01:39Z

src/port/posix/bsd_socket.c

+            } while (1);
+            errno = ret;
+            pthread_mutex_unlock(&wolfIP_mutex);


This wrapper mixes host EAGAIN with wolfIP's -WOLFIP_EAGAIN and also assigns errno = ret (negative). Use wolfIP's return convention consistently: compare against -WOLFIP_EAGAIN and set errno to -ret when returning -1.

Copilot · 2026-03-03T22:01:39Z

src/wolfip.c

+        while (desc) {
+            uint8_t *frame = p->txmem + desc->pos + sizeof(*desc);
+            unsigned int tx_if = p->if_idx;
+            if (tx_if >= s->if_count)
+                tx_if = 0;
+            if (wolfIP_filter_notify_eth(WOLFIP_FILT_SENDING, s, tx_if,
+                                         (struct wolfIP_eth_frame *)frame, desc->len) != 0) {
+                desc = fifo_next(&p->txbuf, desc);
+                continue;


The loop advances desc with fifo_next() when a packet is filtered, but later always removes the head element with fifo_pop(). If desc is not the head, this can send one packet while popping a different one (queue corruption / wrong packet dropped). Since fifo_pop() only pops the head, the safe options are to (a) process only the head (on filter reject: break;), or (b) explicitly drop the head on filter reject (pop it) rather than skipping ahead.

Suggested change

while (desc) {

uint8_t *frame = p->txmem + desc->pos + sizeof(*desc);

unsigned int tx_if = p->if_idx;

if (tx_if >= s->if_count)

tx_if = 0;

if (wolfIP_filter_notify_eth(WOLFIP_FILT_SENDING, s, tx_if,

(struct wolfIP_eth_frame *)frame, desc->len) != 0) {

desc = fifo_next(&p->txbuf, desc);

continue;

/* Drop filtered packet from the head of the FIFO. */

fifo_pop(&p->txbuf);

}

else {

struct wolfIP_ll_dev *ll = wolfIP_ll_at(s, tx_if);

if (ll && ll->send)

ll->send(ll, frame, desc->len);

fifo_pop(&p->txbuf);

}

Copilot · 2026-03-03T22:01:39Z

src/wolfip.c

+                continue;
+            }
+            {


The loop advances desc with fifo_next() when a packet is filtered, but later always removes the head element with fifo_pop(). If desc is not the head, this can send one packet while popping a different one (queue corruption / wrong packet dropped). Since fifo_pop() only pops the head, the safe options are to (a) process only the head (on filter reject: break;), or (b) explicitly drop the head on filter reject (pop it) rather than skipping ahead.

src/wolfip.c

Copilot · 2026-03-03T22:01:40Z

src/wolfip.c

+        if (!ps)
+            return -WOLFIP_EINVAL;
+        if (sll && addrlen && *addrlen < sizeof(struct wolfIP_sockaddr_ll))
+            return -WOLFIP_EINVAL;


Same issue as the raw socket path: returning plain -1 makes the error ambiguous for callers. Prefer a -WOLFIP_* error code consistent with other recv/send failures.

Suggested change

return -WOLFIP_EINVAL;

return -WOLFIP_EMSGSIZE;

Copilot · 2026-03-03T22:01:40Z

src/wolfip.c

+            return 0;
+        }
+        return -WOLFIP_EINVAL;
+    }
+#endif
+#if WOLFIP_PACKET_SOCKETS


For packet sockets, setsockopt currently returns success for any option and even ignores optval/optlen. This can mask real caller errors and diverges from the raw/INET behavior (which returns -WOLFIP_EINVAL for unsupported options). If no options are supported yet, return -WOLFIP_EINVAL (or selectively implement supported options) and validate optval/optlen accordingly.

Suggested change

return 0;

}

return -WOLFIP_EINVAL;

}

#endif

#if WOLFIP_PACKET_SOCKETS

/* No socket options are currently supported for packet sockets.

* To avoid masking caller errors and to match raw/INET behavior,

* reject all setsockopt calls on packet sockets.

*/

(void)s;

return -WOLFIP_EINVAL;

Copilot AI review requested due to automatic review settings March 3, 2026 17:22

Copilot started reviewing on behalf of danielinux March 3, 2026 17:23 View session

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danielinux mentioned this pull request Mar 3, 2026

Raw sockets #10

Closed

danielinux added 2 commits March 3, 2026 18:47

Fix unit test coverage + failing raw sockets tests

dfd8d65

Fix: asan failure in unit tests when udp packet is too short

b6182ff

Copilot AI review requested due to automatic review settings March 3, 2026 18:34

Fixed potential overwrite found by cppcheck

c11f71e

Copilot started reviewing on behalf of danielinux March 3, 2026 18:39 View session

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danielinux requested a review from Copilot March 3, 2026 21:00

Copilot started reviewing on behalf of danielinux March 3, 2026 21:01 View session

Addressed copilot's review comments.

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Removed unused variable

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Copilot AI review requested due to automatic review settings March 3, 2026 21:53

danielinux added 2 commits March 3, 2026 22:55

Fix build / CI

5d7f141

Addressed more copilot review comments

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