diff options
Diffstat (limited to 'unix/psocks.c')
-rw-r--r-- | unix/psocks.c | 176 |
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); +} |