1 files changed, 127 insertions, 0 deletions
diff --git a/stacks/max25-bcpr/src/bcpr_kiss.c b/stacks/max25-bcpr/src/bcpr_kiss.c
new file mode 100644
index 0000000..495f4d1
--- /dev/null
+++ b/stacks/max25-bcpr/src/bcpr_kiss.c
@@ -0,0 +1,127 @@
+/*
+ * KISS PTY bridge for max25-bcpr (HyBBX attach via kiss_link symlink).
+ */
+#define _GNU_SOURCE
+#include "bcpr/bcpr_kiss.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#if defined(__linux__)
+#include <pty.h>
+#elif defined(__FreeBSD__)
+#include <libutil.h>
+#else
+#include <util.h>
+#endif
+
+static int ensure_dir(const char *path)
+{
+    char tmp[256];
+    char *p;
+    size_t len;
+
+    if (!path || !path[0]) {
+        return -1;
+    }
+    snprintf(tmp, sizeof(tmp), "%s", path);
+    len = strlen(tmp);
+    if (len == 0) {
+        return -1;
+    }
+    if (tmp[len - 1] == '/') {
+        tmp[len - 1] = '\0';
+    }
+    for (p = tmp + 1; *p; p++) {
+        if (*p == '/') {
+            *p = '\0';
+            (void)mkdir(tmp, 0755);
+            *p = '/';
+        }
+    }
+    return mkdir(tmp, 0755) == 0 || errno == EEXIST ? 0 : -1;
+}
+
+int bcpr_kiss_pty_open(bcpr_kiss_pty_t *kp, int idx, const char *link_path,
+                       const char *state_dir)
+{
+    int master = -1, slave = -1;
+    char slave_name[128];
+    char dir[128];
+    const char *slash;
+
+    memset(kp, 0, sizeof(*kp));
+    kp->idx = idx;
+    kp->master_fd = -1;
+    kp->slave_fd = -1;
+    snprintf(kp->link_path, sizeof(kp->link_path), "%s", link_path);
+
+    slash = strrchr(link_path, '/');
+    if (slash && slash > link_path) {
+        size_t n = (size_t)(slash - link_path);
+        if (n >= sizeof(dir)) {
+            n = sizeof(dir) - 1;
+        }
+        memcpy(dir, link_path, n);
+        dir[n] = '\0';
+        (void)ensure_dir(dir);
+    } else {
+        (void)ensure_dir(state_dir);
+    }
+
+    if (openpty(&master, &slave, slave_name, NULL, NULL) != 0) {
+        perror("max25-bcpr openpty");
+        return -1;
+    }
+    if (fchmod(slave, 0660) != 0) {
+        perror("max25-bcpr fchmod kiss slave");
+    } else {
+        struct group *gr = getgrnam("dialout");
+        if (gr == NULL) {
+            gr = getgrnam("uucp");
+        }
+        if (gr == NULL) {
+            gr = getgrnam("tty");
+        }
+        if (gr != NULL && fchown(slave, (uid_t)-1, gr->gr_gid) != 0) {
+            perror("max25-bcpr fchown kiss slave");
+        }
+    }
+    unlink(link_path);
+    if (symlink(slave_name, link_path) != 0) {
+        perror("max25-bcpr symlink kiss_link");
+        close(slave);
+        close(master);
+        return -1;
+    }
+    fcntl(master, F_SETFL, O_NONBLOCK);
+    kp->master_fd = master;
+    close(slave);
+    kp->slave_fd = -1;
+    fprintf(stderr, "max25-bcpr: max25e0:bc%d KISS → %s -> %s\n", idx, link_path,
+            slave_name);
+    return 0;
+}
+
+void bcpr_kiss_pty_close(bcpr_kiss_pty_t *kp)
+{
+    if (!kp) {
+        return;
+    }
+    if (kp->slave_fd >= 0) {
+        close(kp->slave_fd);
+        kp->slave_fd = -1;
+    }
+    if (kp->master_fd >= 0) {
+        close(kp->master_fd);
+        kp->master_fd = -1;
+    }
+    if (kp->link_path[0]) {
+        unlink(kp->link_path);
+    }
+}