1 files changed, 176 insertions, 0 deletions
diff --git a/unix/psocks.c b/unix/psocks.c
new file mode 100644
index 00000000..748790b8
--- /dev/null
+++ b/unix/psocks.c
@@ -0,0 +1,176 @@
+/*
+ * Main program for Unix psocks.
+ */
+
+#include <string.h>
+#include <errno.h>
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "putty.h"
+#include "ssh.h"
+#include "psocks.h"
+
+typedef struct PsocksDataSinkPopen {
+    stdio_sink sink[2];
+    PsocksDataSink pds;
+} PsocksDataSinkPopen;
+
+static void popen_free(PsocksDataSink *pds)
+{
+    PsocksDataSinkPopen *pdsp = container_of(pds, PsocksDataSinkPopen, pds);
+    for (size_t i = 0; i < 2; i++)
+        pclose(pdsp->sink[i].fp);
+    sfree(pdsp);
+}
+
+static PsocksDataSink *open_pipes(
+    const char *cmd, const char *const *direction_args,
+    const char *index_arg, char **err)
+{
+    FILE *fp[2];
+    char *errmsg = NULL;
+
+    for (size_t i = 0; i < 2; i++) {
+        /* No escaping needed: the provided command is already
+         * shell-quoted, and our extra arguments are simple */
+        char *command = dupprintf("%s %s %s", cmd,
+                                  direction_args[i], index_arg);
+
+        fp[i] = popen(command, "w");
+        sfree(command);
+
+        if (!fp[i]) {
+            if (!errmsg)
+                errmsg = dupprintf("%s", strerror(errno));
+        }
+    }
+
+    if (errmsg) {
+        for (size_t i = 0; i < 2; i++)
+            if (fp[i])
+                pclose(fp[i]);
+        *err = errmsg;
+        return NULL;
+    }
+
+    PsocksDataSinkPopen *pdsp = snew(PsocksDataSinkPopen);
+
+    for (size_t i = 0; i < 2; i++) {
+        setvbuf(fp[i], NULL, _IONBF, 0);
+        stdio_sink_init(&pdsp->sink[i], fp[i]);
+        pdsp->pds.s[i] = BinarySink_UPCAST(&pdsp->sink[i]);
+    }
+
+    pdsp->pds.free = popen_free;
+
+    return &pdsp->pds;
+}
+
+static int signalpipe[2] = { -1, -1 };
+static void sigchld(int signum)
+{
+    if (write(signalpipe[1], "x", 1) <= 0)
+        /* not much we can do about it */;
+}
+
+static pid_t subcommand_pid = -1;
+
+static bool still_running = true;
+
+static void start_subcommand(strbuf *args)
+{
+    pid_t pid;
+
+    /*
+     * Set up the pipe we'll use to tell us about SIGCHLD.
+     */
+    if (pipe(signalpipe) < 0) {
+        perror("pipe");
+        exit(1);
+    }
+    putty_signal(SIGCHLD, sigchld);
+
+    /*
+     * Make an array of argument pointers that execvp will like.
+     */
+    size_t nargs = 0;
+    for (size_t i = 0; i < args->len; i++)
+        if (args->s[i] == '\0')
+            nargs++;
+
+    char **exec_args = snewn(nargs + 1, char *);
+    char *p = args->s;
+    for (size_t a = 0; a < nargs; a++) {
+        exec_args[a] = p;
+        size_t len = strlen(p);
+        assert(len < args->len - (p - args->s));
+        p += 1 + len;
+    }
+    exec_args[nargs] = NULL;
+
+    pid = fork();
+    if (pid < 0) {
+        perror("fork");
+        exit(1);
+    } else if (pid == 0) {
+        execvp(exec_args[0], exec_args);
+        perror("exec");
+        _exit(127);
+    } else {
+        subcommand_pid = pid;
+        sfree(exec_args);
+    }
+}
+
+static const PsocksPlatform platform = {
+    open_pipes,
+    start_subcommand,
+};
+
+static bool psocks_pw_setup(void *ctx, pollwrapper *pw)
+{
+    if (signalpipe[0] >= 0)
+        pollwrap_add_fd_rwx(pw, signalpipe[0], SELECT_R);
+    return true;
+}
+
+static void psocks_pw_check(void *ctx, pollwrapper *pw)
+{
+    if (signalpipe[0] >= 0 &&
+        pollwrap_check_fd_rwx(pw, signalpipe[0], SELECT_R)) {
+        while (true) {
+            int status;
+            pid_t pid = waitpid(-1, &status, WNOHANG);
+            if (pid <= 0)
+                break;
+            if (pid == subcommand_pid)
+                still_running = false;
+        }
+    }
+}
+
+static bool psocks_continue(void *ctx, bool found_any_fd,
+                            bool ran_any_callback)
+{
+    return still_running;
+}
+
+typedef bool (*cliloop_continue_t)(void *ctx, bool found_any_fd,
+                                   bool ran_any_callback);
+
+int main(int argc, char **argv)
+{
+    psocks_state *ps = psocks_new(&platform);
+    psocks_cmdline(ps, argc, argv);
+
+    sk_init();
+    uxsel_init();
+    psocks_start(ps);
+
+    cli_main_loop(psocks_pw_setup, psocks_pw_check, psocks_continue, NULL);
+}