From 6834db53b239f35c590523f2528deb9144784880 Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 08:01:54 +1100
Subject: [PATCH 01/13] Allow tracking how many bytes are read into a conn
 struct

---
 libs/connslot/connslot.c | 9 +++++----
 libs/connslot/connslot.h | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/libs/connslot/connslot.c b/libs/connslot/connslot.c
index b0382c7..f730cce 100644
--- a/libs/connslot/connslot.c
+++ b/libs/connslot/connslot.c
@@ -177,7 +177,7 @@ void conn_check_ready(conn_t *conn) {
     return;
 }
 
-void conn_read(conn_t *conn, int fd) {
+ssize_t conn_read(conn_t *conn, int fd) {
     conn->state = CONN_READING;
 
     // If no space available, try increasing our capacity
@@ -195,21 +195,22 @@ void conn_read(conn_t *conn, int fd) {
         // zero-sized read request, the only time we get a zero back is if the
         // far end has closed
         conn->state = CONN_CLOSED;
-        return;
+        return 0;
     }
 
     if (size == -1) {
         if (errno == EWOULDBLOCK || errno == EAGAIN) {
             conn->state = CONN_EMPTY;
-            return;
+            return 0;
         }
         conn->state = CONN_ERROR;
-        return;
+        return 0;
     }
 
     // This will truncate the time to a int - usually 32bits
     conn->activity = time(NULL);
     conn_check_ready(conn);
+    return size;
 }
 
 ssize_t conn_write(conn_t *conn, int fd) {
diff --git a/libs/connslot/connslot.h b/libs/connslot/connslot.h
index fc24325..2ce3fb5 100644
--- a/libs/connslot/connslot.h
+++ b/libs/connslot/connslot.h
@@ -64,7 +64,7 @@ void conn_zero(conn_t *);
 int conn_init(conn_t *, size_t, size_t);
 void conn_accept(conn_t *, int, enum conn_proto);
 void conn_check_ready(conn_t *);
-void conn_read(conn_t *, int);
+ssize_t conn_read(conn_t *, int);
 ssize_t conn_write(conn_t *, int);
 int conn_iswriter(conn_t *);
 void conn_close(conn_t *, int);

From 8815dc5f44e831ab7f98d42f6faa84294af9b6f8 Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 08:02:41 +1100
Subject: [PATCH 02/13] Just because a read would block, doesnt make the conn
 empty

---
 libs/connslot/connslot.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/libs/connslot/connslot.c b/libs/connslot/connslot.c
index f730cce..6bef3c7 100644
--- a/libs/connslot/connslot.c
+++ b/libs/connslot/connslot.c
@@ -200,7 +200,6 @@ ssize_t conn_read(conn_t *conn, int fd) {
 
     if (size == -1) {
         if (errno == EWOULDBLOCK || errno == EAGAIN) {
-            conn->state = CONN_EMPTY;
             return 0;
         }
         conn->state = CONN_ERROR;

From 6648dcb42f3eefaa7162e9cdd3de6a26863ef0de Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 08:03:32 +1100
Subject: [PATCH 03/13] Deprecate the use of the CONN_SENDING state to allow
 easier bi-directional traffic

---
 libs/connslot/connslot.c | 21 +++++++++++++--------
 libs/connslot/connslot.h |  2 +-
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/libs/connslot/connslot.c b/libs/connslot/connslot.c
index 6bef3c7..f72de20 100644
--- a/libs/connslot/connslot.c
+++ b/libs/connslot/connslot.c
@@ -215,8 +215,6 @@ ssize_t conn_read(conn_t *conn, int fd) {
 ssize_t conn_write(conn_t *conn, int fd) {
     ssize_t sent;
 
-    conn->state = CONN_SENDING;
-
     if (fd == -1) {
         return 0;
     }
@@ -282,13 +280,20 @@ ssize_t conn_write(conn_t *conn, int fd) {
     return sent;
 }
 
-int conn_iswriter(conn_t *conn) {
-    switch (conn->state) {
-        case CONN_SENDING:
-            return 1;
-        default:
-            return 0;
+bool conn_iswriter(conn_t *conn) {
+    int endpos = 0;
+    if (conn->reply_header) {
+        endpos += sb_len(conn->reply_header);
+    }
+    if (conn->reply) {
+        endpos += sb_len(conn->reply);
     }
+
+    // If there are any bytes ready to send, then we are writable
+    if(endpos) {
+        return true;
+    }
+    return false;
 }
 
 void conn_close(conn_t *conn, int fd) {
diff --git a/libs/connslot/connslot.h b/libs/connslot/connslot.h
index 2ce3fb5..964a178 100644
--- a/libs/connslot/connslot.h
+++ b/libs/connslot/connslot.h
@@ -66,7 +66,7 @@ void conn_accept(conn_t *, int, enum conn_proto);
 void conn_check_ready(conn_t *);
 ssize_t conn_read(conn_t *, int);
 ssize_t conn_write(conn_t *, int);
-int conn_iswriter(conn_t *);
+bool conn_iswriter(conn_t *);
 void conn_close(conn_t *, int);
 bool conn_closeidle(conn_t *, int, int, int);
 void conn_dump(strbuf_t **, conn_t *);

From 5f63b464e5973c3437aa09cb2f6496f2235e0451 Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 08:04:00 +1100
Subject: [PATCH 04/13] Just because we have finished writing doesnt make the
 read side empty

---
 libs/connslot/connslot.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/libs/connslot/connslot.c b/libs/connslot/connslot.c
index f72de20..596566f 100644
--- a/libs/connslot/connslot.c
+++ b/libs/connslot/connslot.c
@@ -269,7 +269,6 @@ ssize_t conn_write(conn_t *conn, int fd) {
 
     if (conn->reply_sendpos >= end_pos) {
         // We have sent the last bytes of this reply
-        conn->state = CONN_EMPTY;
         conn->reply_sendpos = 0;
         sb_zero(conn->reply_header);
         sb_zero(conn->reply);

From b274360ce5167bfcc638266457760bad5a24e2fa Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 08:04:51 +1100
Subject: [PATCH 05/13] Ensure that the non blocking states are handled in the
 write path (and dont decrement the sendpos)

---
 libs/connslot/connslot.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/libs/connslot/connslot.c b/libs/connslot/connslot.c
index 596566f..03f0ce4 100644
--- a/libs/connslot/connslot.c
+++ b/libs/connslot/connslot.c
@@ -265,6 +265,13 @@ ssize_t conn_write(conn_t *conn, int fd) {
     unsigned int end_pos = sb_len(conn->reply_header) + sb_len(conn->reply);
 #endif
 
+    if (sent == -1) {
+        sent = 0;
+        if (errno != EAGAIN && errno != EWOULDBLOCK) {
+            conn->state = CONN_ERROR;
+        }
+    }
+
     conn->reply_sendpos += sent;
 
     if (conn->reply_sendpos >= end_pos) {

From b5ef52846690101edaa04e6118895892db70dca2 Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 08:06:08 +1100
Subject: [PATCH 06/13] Increase readability by clearly showing the ITER basic
 block as indented

---
 src/edge_utils.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/edge_utils.c b/src/edge_utils.c
index e92efbb..bee9b2b 100644
--- a/src/edge_utils.c
+++ b/src/edge_utils.c
@@ -1630,11 +1630,13 @@ void update_supernode_reg (struct n3n_runtime_data * eee, time_t now) {
         if(eee->conf.bind_address) {
             // do not explicitly disconnect every time as the condition described is rare, so ...
             // ... check that there are no external peers (indicating a working socket) ...
-            HASH_ITER(hh, eee->known_peers, peer, tmp_peer)
-            if(!peer->local) {
-                cnt++;
-                break;
+            HASH_ITER(hh, eee->known_peers, peer, tmp_peer) {
+                if(!peer->local) {
+                    cnt++;
+                    break;
+                }
             }
+
             if(!cnt) {
                 // ... and then count the connection retries
                 (eee->close_socket_counter)++;

From 9810e9e42bff4d7df0e2547a3a46245ad8e16597 Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 08:07:18 +1100
Subject: [PATCH 07/13] Update user visible message to not claim UDP - both TCP
 and UDP are processed here

---
 src/edge_utils.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/edge_utils.c b/src/edge_utils.c
index bee9b2b..151db20 100644
--- a/src/edge_utils.c
+++ b/src/edge_utils.c
@@ -2299,7 +2299,7 @@ void process_udp (struct n3n_runtime_data *eee,
     via_multicast = (in_sock == eee->udp_multicast_sock);
 #endif
 
-    traceEvent(TRACE_DEBUG, "Rx N2N_UDP of size %d from [%s]",
+    traceEvent(TRACE_DEBUG, "Rx VPN packet of size %d from [%s]",
                (signed int)udp_size, sock_to_cstr(sockbuf1, &sender));
 
     if(eee->conf.header_encryption == HEADER_ENCRYPTION_ENABLED) {

From d0b35e534d04ddedafd5dfe4b49350db89e21dab Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 08:08:13 +1100
Subject: [PATCH 08/13] Avoid trying to process the release of an error fd

---
 src/mainloop.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/mainloop.c b/src/mainloop.c
index 5bc7ab9..9cb84f8 100644
--- a/src/mainloop.c
+++ b/src/mainloop.c
@@ -226,6 +226,10 @@ static int fdlist_allocslot (int fd, enum fd_info_proto proto) {
 
 static void fdlist_freefd (int fd) {
     int slot = 0;
+    if(fd == -1) {
+        // Cannot release an error fd!
+        return;
+    }
     while(slot < MAX_HANDLES) {
         if(fdlist[slot].fd != fd) {
             slot++;

From 71d4e5c8c84a907d93e11a7656976fd399b9f274 Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 08:09:39 +1100
Subject: [PATCH 09/13] Clearly log errors with some setsockopts

---
 src/n2n.c | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/n2n.c b/src/n2n.c
index 2101643..9c99d0a 100644
--- a/src/n2n.c
+++ b/src/n2n.c
@@ -62,8 +62,41 @@ SOCKET open_socket (struct sockaddr *local_address, socklen_t addrlen, int type
     /* fcntl(sock_fd, F_SETFL, O_NONBLOCK); */
 #endif
 
+    int result;
+
     sockopt = 1;
-    setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, (char *)&sockopt, sizeof(sockopt));
+    result = setsockopt(
+        sock_fd,
+        SOL_SOCKET,
+        SO_REUSEADDR,
+        (char *)&sockopt,
+        sizeof(sockopt)
+    );
+    if(result == -1) {
+        traceEvent(
+            TRACE_ERROR,
+            "SO_REUSEADDR fd=%i, error=%s\n",
+            sock_fd,
+            strerror(errno)
+        );
+    }
+#ifdef SO_REUSEPORT /* no SO_REUSEPORT in Windows / old linux versions */
+    result = setsockopt(
+        sock_fd,
+        SOL_SOCKET,
+        SO_REUSEPORT,
+        (char *)&sockopt,
+        sizeof(sockopt)
+    );
+    if(result == -1) {
+        traceEvent(
+            TRACE_ERROR,
+            "SO_REUSEPORT fd=%i, error=%s\n",
+            sock_fd,
+            strerror(errno)
+        );
+    }
+#endif
 
     if(!local_address) {
         // skip binding if we dont have the right details

From 99ffa5efa8ab2458cd0d02972b9bcadc3cbb3504 Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 08:09:57 +1100
Subject: [PATCH 10/13] Ensure we do not ignore the return value for a write

---
 tools/crypto_helper.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/tools/crypto_helper.c b/tools/crypto_helper.c
index f1a47e3..0bea38f 100644
--- a/tools/crypto_helper.c
+++ b/tools/crypto_helper.c
@@ -96,7 +96,10 @@ static void cmd_header_decrypt (int argc, char **argv, void *conf) {
         exit(1);
     }
 
-    write(1, &buf, size);
+    int r = write(1, &buf, size);
+    if(r != size) {
+        printf("Short write\n");
+    }
     exit(0);
 
 }
@@ -130,7 +133,10 @@ static void cmd_pearson_128 (int argc, char **argv, void *conf) {
     unsigned char hash[16];
     size = read(0, &buf, sizeof(buf));
     pearson_hash_128(hash, buf, size);
-    write(1, &hash, sizeof(hash));
+    int r = write(1, &hash, sizeof(hash));
+    if(r != sizeof(hash)) {
+        printf("Short write\n");
+    }
     exit(0);
 }
 

From 0d4d19b7d84bced83c621641d1fb70a6f579786d Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Thu, 12 Dec 2024 19:25:43 +1100
Subject: [PATCH 11/13] Use a specified OS version for all lint tests

The switch to a newer ubuntu-24.04 also imported a set of lint tests
that do not match anything the dev systems are using.
---
 .github/workflows/quick.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/quick.yml b/.github/workflows/quick.yml
index f3da7c5..61d2061 100644
--- a/.github/workflows/quick.yml
+++ b/.github/workflows/quick.yml
@@ -36,7 +36,7 @@ jobs:
 
   smoketest_all_opts:
     name: Smoke test With all options turned on
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
 
     steps:
       - uses: actions/checkout@v4
@@ -75,7 +75,7 @@ jobs:
       - name: Generate coverage reports
         run: |
           make gcov
-          make cover COVERAGEDIR=coverage/ubuntu-latest
+          make cover COVERAGEDIR=coverage/ubuntu-22.04
         shell: bash
 
       - name: Upload gcovr report artifact
@@ -114,7 +114,7 @@ jobs:
 
   lint:
     name: Code syntax
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
 
     steps:
       - uses: actions/checkout@v4

From 021d831dc904335a34da2af255bdd58090e276ba Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Mon, 16 Dec 2024 21:20:59 +1100
Subject: [PATCH 12/13] Add an example container build

---
 doc/Containerfile.example | 46 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 doc/Containerfile.example

diff --git a/doc/Containerfile.example b/doc/Containerfile.example
new file mode 100644
index 0000000..f284117
--- /dev/null
+++ b/doc/Containerfile.example
@@ -0,0 +1,46 @@
+#
+# A simple example of how to build a docker container for n3n-edge
+#
+# Build with the command:
+# podman build \
+#   --device=/dev/net/tun \
+#   --cap-add=NET_ADMIN \
+#   -t=n3n \
+#   -f doc/Containerfile.example \
+#   .
+#
+# Start a n3n session with:
+# podman run \
+#   -it \
+#   --name=n3n \
+#   --device=/dev/net/tun \
+#   --cap-add=NET_ADMIN \
+#   -v $PWD/n3n:/etc/n3n/ \
+#   n3n start -vvvv
+#
+# Note that the build could be done without the --device and --cap-add if
+# the `make test` is omitted
+
+FROM docker.io/library/debian:12 AS builder
+
+RUN apt-get update
+RUN apt-get install -y build-essential autoconf git python3 jq sudo
+
+WORKDIR /n3n
+
+COPY . .
+
+RUN \
+    ./autogen.sh && \
+    ./configure && \
+    make clean all && \
+    make test
+
+
+FROM docker.io/library/debian:12
+
+COPY --from=builder /n3n/apps/n3n-edge /n3n-edge
+
+VOLUME [ "/etc/n3n" ]
+ENTRYPOINT ["/n3n-edge"]
+CMD ["start"]

From 73d198abfc4a75389f7ad0a59ffc8de5aba783a2 Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Mon, 16 Dec 2024 21:23:06 +1100
Subject: [PATCH 13/13] Finish removal of CONN_SENDING state

---
 libs/connslot/connslot.h | 1 -
 src/mainloop.c           | 2 --
 2 files changed, 3 deletions(-)

diff --git a/libs/connslot/connslot.h b/libs/connslot/connslot.h
index 964a178..f710106 100644
--- a/libs/connslot/connslot.h
+++ b/libs/connslot/connslot.h
@@ -29,7 +29,6 @@ enum __attribute__((__packed__)) conn_state {
     CONN_EMPTY = 0,
     CONN_READING = 1,
     CONN_READY = 2,
-    CONN_SENDING = 3,
     CONN_CLOSED = 4,
     CONN_ERROR = 5,
 };
diff --git a/src/mainloop.c b/src/mainloop.c
index 9cb84f8..cf6aff0 100644
--- a/src/mainloop.c
+++ b/src/mainloop.c
@@ -335,7 +335,6 @@ static void handle_fd (const time_t now, const struct fd_info info, struct n3n_r
             switch(conn->state) {
                 case CONN_EMPTY:
                 case CONN_READING:
-                case CONN_SENDING:
                     // These states dont require us to do anything
                     // TODO:
                     // - handle reading/sending simultaneous?
@@ -406,7 +405,6 @@ static void handle_fd (const time_t now, const struct fd_info info, struct n3n_r
             switch(conn->state) {
                 case CONN_EMPTY:
                 case CONN_READING:
-                case CONN_SENDING:
                     // These states dont require us to do anything
                     // TODO:
                     // - handle reading/sending simultaneous?