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-rw-r--r--common/exectool.c650
1 files changed, 650 insertions, 0 deletions
diff --git a/common/exectool.c b/common/exectool.c
new file mode 100644
index 0000000..3458de4
--- /dev/null
+++ b/common/exectool.c
@@ -0,0 +1,650 @@
+/* exectool.c - Utility functions to execute a helper tool
+ * Copyright (C) 2015 Werner Koch
+ * Copyright (C) 2016 g10 Code GmbH
+ *
+ * This file is part of GnuPG.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either
+ *
+ * - the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * or
+ *
+ * - the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * or both in parallel, as here.
+ *
+ * This file is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <assert.h>
+#include <gpg-error.h>
+
+#include <assuan.h>
+#include "i18n.h"
+#include "logging.h"
+#include "membuf.h"
+#include "mischelp.h"
+#include "exechelp.h"
+#include "sysutils.h"
+#include "util.h"
+#include "exectool.h"
+
+typedef struct
+{
+ const char *pgmname;
+ exec_tool_status_cb_t status_cb;
+ void *status_cb_value;
+ int cont;
+ size_t used;
+ size_t buffer_size;
+ char *buffer;
+} read_and_log_buffer_t;
+
+
+static inline gpg_error_t
+my_error_from_syserror (void)
+{
+ return gpg_err_make (default_errsource, gpg_err_code_from_syserror ());
+}
+
+
+static void
+read_and_log_stderr (read_and_log_buffer_t *state, es_poll_t *fderr)
+{
+ gpg_error_t err;
+ int c;
+
+ if (!fderr)
+ {
+ /* Flush internal buffer. */
+ if (state->used)
+ {
+ const char *pname;
+ int len;
+
+ state->buffer[state->used] = 0;
+ state->used = 0;
+
+ pname = strrchr (state->pgmname, '/');
+ if (pname && pname != state->pgmname && pname[1])
+ pname++;
+ else
+ pname = state->pgmname;
+ len = strlen (pname);
+
+ if (state->status_cb
+ && !strncmp (state->buffer, "[GNUPG:] ", 9)
+ && state->buffer[9] >= 'A' && state->buffer[9] <= 'Z')
+ {
+ char *rest;
+
+ rest = strchr (state->buffer + 9, ' ');
+ if (!rest)
+ {
+ /* Set REST to an empty string. */
+ rest = state->buffer + strlen (state->buffer);
+ }
+ else
+ {
+ *rest++ = 0;
+ trim_spaces (rest);
+ }
+ state->status_cb (state->status_cb_value,
+ state->buffer + 9, rest);
+ }
+ else if (!state->cont
+ && !strncmp (state->buffer, pname, len)
+ && strlen (state->buffer) > strlen (pname)
+ && state->buffer[len] == ':' )
+ {
+ /* PGMNAME plus colon is identical to the start of
+ the output: print only the output. */
+ log_info ("%s\n", state->buffer);
+ }
+ else
+ log_info ("%s%c %s\n",
+ pname, state->cont? '+':':', state->buffer);
+ }
+ state->cont = 0;
+ return;
+ }
+ for (;;)
+ {
+ c = es_fgetc (fderr->stream);
+ if (c == EOF)
+ {
+ if (es_feof (fderr->stream))
+ {
+ fderr->ignore = 1; /* Not anymore needed. */
+ }
+ else if (es_ferror (fderr->stream))
+ {
+ err = my_error_from_syserror ();
+ log_error ("error reading stderr of '%s': %s\n",
+ state->pgmname, gpg_strerror (err));
+ fderr->ignore = 1; /* Disable. */
+ }
+
+ break;
+ }
+ else if (c == '\n')
+ {
+ read_and_log_stderr (state, NULL);
+ }
+ else
+ {
+ if (state->used >= state->buffer_size - 1)
+ {
+ if (state->status_cb)
+ {
+ /* A status callback requires that we have a full
+ * line. Thus we need to enlarget the buffer in
+ * this case. */
+ char *newbuffer;
+ size_t newsize = state->buffer_size + 256;
+
+ newbuffer = xtrymalloc (newsize);
+ if (!newbuffer)
+ {
+ log_error ("error allocating memory for status cb: %s\n",
+ gpg_strerror (my_error_from_syserror ()));
+ /* We better disable the status CB in this case. */
+ state->status_cb = NULL;
+ read_and_log_stderr (state, NULL);
+ state->cont = 1;
+ }
+ else
+ {
+ memcpy (newbuffer, state->buffer, state->used);
+ xfree (state->buffer);
+ state->buffer = newbuffer;
+ state->buffer_size = newsize;
+ }
+ }
+ else
+ {
+ read_and_log_stderr (state, NULL);
+ state->cont = 1;
+ }
+ }
+ state->buffer[state->used++] = c;
+ }
+ }
+}
+
+
+
+/* A buffer to copy from one stream to another. */
+struct copy_buffer
+{
+ char buffer[4096];
+ char *writep;
+ size_t nread;
+};
+
+
+/* Initialize a copy buffer. */
+static void
+copy_buffer_init (struct copy_buffer *c)
+{
+ c->writep = c->buffer;
+ c->nread = 0;
+}
+
+
+/* Securely wipe a copy buffer. */
+static void
+copy_buffer_shred (struct copy_buffer *c)
+{
+ if (c == NULL)
+ return;
+ wipememory (c->buffer, sizeof c->buffer);
+ c->writep = NULL;
+ c->nread = ~0U;
+}
+
+
+/* Copy data from SOURCE to SINK using copy buffer C. */
+static gpg_error_t
+copy_buffer_do_copy (struct copy_buffer *c, estream_t source, estream_t sink)
+{
+ gpg_error_t err;
+ size_t nwritten = 0;
+
+ if (c->nread == 0)
+ {
+ c->writep = c->buffer;
+ if (es_read (source, c->buffer, sizeof c->buffer, &c->nread))
+ {
+ err = my_error_from_syserror ();
+ if (gpg_err_code (err) == GPG_ERR_EAGAIN)
+ return 0; /* We will just retry next time. */
+
+ return err;
+ }
+
+ log_assert (c->nread <= sizeof c->buffer);
+ }
+
+ if (c->nread == 0)
+ return 0; /* Done copying. */
+
+ nwritten = 0;
+ if (sink && es_write (sink, c->writep, c->nread, &nwritten))
+ err = my_error_from_syserror ();
+ else
+ err = 0;
+
+ log_assert (nwritten <= c->nread);
+ c->writep += nwritten;
+ c->nread -= nwritten;
+ log_assert (c->writep - c->buffer <= sizeof c->buffer);
+
+ if (err)
+ {
+ if (gpg_err_code (err) == GPG_ERR_EAGAIN)
+ return 0; /* We will just retry next time. */
+
+ return err;
+ }
+
+ if (sink && es_fflush (sink) && errno != EAGAIN)
+ err = my_error_from_syserror ();
+
+ return err;
+}
+
+
+/* Flush the remaining data to SINK. */
+static gpg_error_t
+copy_buffer_flush (struct copy_buffer *c, estream_t sink)
+{
+ gpg_error_t err = 0;
+ size_t nwritten = 0;
+
+ if (es_write (sink, c->writep, c->nread, &nwritten))
+ err = my_error_from_syserror ();
+
+ log_assert (nwritten <= c->nread);
+ c->writep += nwritten;
+ c->nread -= nwritten;
+ log_assert (c->writep - c->buffer <= sizeof c->buffer);
+
+ if (err)
+ return err;
+
+ if (es_fflush (sink))
+ err = my_error_from_syserror ();
+
+ return err;
+}
+
+
+
+/* Run the program PGMNAME with the command line arguments given in
+ * the NULL terminates array ARGV. If INPUT is not NULL it will be
+ * fed to stdin of the process. stderr is logged using log_info and
+ * the process' stdout is written to OUTPUT. If OUTPUT is NULL the
+ * output is discarded. If INEXTRA is given, an additional input
+ * stream will be passed to the child; to tell the child about this
+ * ARGV is scanned and the first occurrence of an argument
+ * "-&@INEXTRA@" is replaced by the concatenation of "-&" and the
+ * child's file descriptor of the pipe created for the INEXTRA stream.
+ *
+ * On error a diagnostic is printed and an error code returned. */
+gpg_error_t
+gnupg_exec_tool_stream (const char *pgmname, const char *argv[],
+ estream_t input, estream_t inextra,
+ estream_t output,
+ exec_tool_status_cb_t status_cb,
+ void *status_cb_value)
+{
+ gpg_error_t err;
+ pid_t pid = (pid_t) -1;
+ estream_t infp = NULL;
+ estream_t extrafp = NULL;
+ estream_t outfp = NULL, errfp = NULL;
+ es_poll_t fds[4];
+ int exceptclose[2];
+ int extrapipe[2] = {-1, -1};
+ char extrafdbuf[20];
+ const char *argsave = NULL;
+ int argsaveidx;
+ int count;
+ read_and_log_buffer_t fderrstate;
+ struct copy_buffer *cpbuf_in = NULL, *cpbuf_out = NULL, *cpbuf_extra = NULL;
+
+ memset (fds, 0, sizeof fds);
+ memset (&fderrstate, 0, sizeof fderrstate);
+
+ cpbuf_in = xtrymalloc (sizeof *cpbuf_in);
+ if (cpbuf_in == NULL)
+ {
+ err = my_error_from_syserror ();
+ goto leave;
+ }
+ copy_buffer_init (cpbuf_in);
+
+ cpbuf_out = xtrymalloc (sizeof *cpbuf_out);
+ if (cpbuf_out == NULL)
+ {
+ err = my_error_from_syserror ();
+ goto leave;
+ }
+ copy_buffer_init (cpbuf_out);
+
+ cpbuf_extra = xtrymalloc (sizeof *cpbuf_extra);
+ if (cpbuf_extra == NULL)
+ {
+ err = my_error_from_syserror ();
+ goto leave;
+ }
+ copy_buffer_init (cpbuf_extra);
+
+ fderrstate.pgmname = pgmname;
+ fderrstate.status_cb = status_cb;
+ fderrstate.status_cb_value = status_cb_value;
+ fderrstate.buffer_size = 256;
+ fderrstate.buffer = xtrymalloc (fderrstate.buffer_size);
+ if (!fderrstate.buffer)
+ {
+ err = my_error_from_syserror ();
+ goto leave;
+ }
+
+ if (inextra)
+ {
+ err = gnupg_create_outbound_pipe (extrapipe, &extrafp, 1);
+ if (err)
+ {
+ log_error ("error running outbound pipe for extra fp: %s\n",
+ gpg_strerror (err));
+ goto leave;
+ }
+ exceptclose[0] = extrapipe[0]; /* Do not close in child. */
+ exceptclose[1] = -1;
+ /* Now find the argument marker and replace by the pipe's fd.
+ Yeah, that is an ugly non-thread safe hack but it safes us to
+ create a copy of the array. */
+#ifdef HAVE_W32_SYSTEM
+ snprintf (extrafdbuf, sizeof extrafdbuf, "-&%lu",
+ (unsigned long)(void*)_get_osfhandle (extrapipe[0]));
+#else
+ snprintf (extrafdbuf, sizeof extrafdbuf, "-&%d", extrapipe[0]);
+#endif
+ for (argsaveidx=0; argv[argsaveidx]; argsaveidx++)
+ if (!strcmp (argv[argsaveidx], "-&@INEXTRA@"))
+ {
+ argsave = argv[argsaveidx];
+ argv[argsaveidx] = extrafdbuf;
+ break;
+ }
+ }
+ else
+ exceptclose[0] = -1;
+
+ err = gnupg_spawn_process (pgmname, argv,
+ exceptclose, NULL, GNUPG_SPAWN_NONBLOCK,
+ input? &infp : NULL,
+ &outfp, &errfp, &pid);
+ if (extrapipe[0] != -1)
+ close (extrapipe[0]);
+ if (argsave)
+ argv[argsaveidx] = argsave;
+ if (err)
+ {
+ log_error ("error running '%s': %s\n", pgmname, gpg_strerror (err));
+ goto leave;
+ }
+
+ fds[0].stream = infp;
+ fds[0].want_write = 1;
+ if (!input)
+ fds[0].ignore = 1;
+ fds[1].stream = outfp;
+ fds[1].want_read = 1;
+ fds[2].stream = errfp;
+ fds[2].want_read = 1;
+ fds[3].stream = extrafp;
+ fds[3].want_write = 1;
+ if (!inextra)
+ fds[3].ignore = 1;
+
+ /* Now read as long as we have something to poll. We continue
+ reading even after EOF or error on stdout so that we get the
+ other error messages or remaining output. */
+ while (! (fds[1].ignore && fds[2].ignore))
+ {
+ count = es_poll (fds, DIM(fds), -1);
+ if (count == -1)
+ {
+ err = my_error_from_syserror ();
+ log_error ("error polling '%s': %s\n", pgmname, gpg_strerror (err));
+ goto leave;
+ }
+ if (!count)
+ {
+ log_debug ("unexpected timeout while polling '%s'\n", pgmname);
+ break;
+ }
+
+ if (fds[0].got_write)
+ {
+ err = copy_buffer_do_copy (cpbuf_in, input, fds[0].stream);
+ if (err)
+ {
+ log_error ("error feeding data to '%s': %s\n",
+ pgmname, gpg_strerror (err));
+ goto leave;
+ }
+
+ if (es_feof (input))
+ {
+ err = copy_buffer_flush (cpbuf_in, fds[0].stream);
+ if (gpg_err_code (err) == GPG_ERR_EAGAIN)
+ continue; /* Retry next time. */
+ if (err)
+ {
+ log_error ("error feeding data to '%s': %s\n",
+ pgmname, gpg_strerror (err));
+ goto leave;
+ }
+
+ fds[0].ignore = 1; /* ready. */
+ es_fclose (infp); infp = NULL;
+ }
+ }
+
+ if (fds[3].got_write)
+ {
+ log_assert (inextra);
+ err = copy_buffer_do_copy (cpbuf_extra, inextra, fds[3].stream);
+ if (err)
+ {
+ log_error ("error feeding data to '%s': %s\n",
+ pgmname, gpg_strerror (err));
+ goto leave;
+ }
+
+ if (es_feof (inextra))
+ {
+ err = copy_buffer_flush (cpbuf_extra, fds[3].stream);
+ if (gpg_err_code (err) == GPG_ERR_EAGAIN)
+ continue; /* Retry next time. */
+ if (err)
+ {
+ log_error ("error feeding data to '%s': %s\n",
+ pgmname, gpg_strerror (err));
+ goto leave;
+ }
+
+ fds[3].ignore = 1; /* ready. */
+ es_fclose (extrafp); extrafp = NULL;
+ }
+ }
+
+ if (fds[1].got_read)
+ {
+ err = copy_buffer_do_copy (cpbuf_out, fds[1].stream, output);
+ if (err)
+ {
+ log_error ("error reading data from '%s': %s\n",
+ pgmname, gpg_strerror (err));
+ goto leave;
+ }
+
+ if (es_feof (fds[1].stream))
+ {
+ err = copy_buffer_flush (cpbuf_out, output);
+ if (err)
+ {
+ log_error ("error reading data from '%s': %s\n",
+ pgmname, gpg_strerror (err));
+ goto leave;
+ }
+
+ fds[1].ignore = 1; /* ready. */
+ }
+ }
+
+ if (fds[2].got_read)
+ read_and_log_stderr (&fderrstate, fds + 2);
+ }
+
+ read_and_log_stderr (&fderrstate, NULL); /* Flush. */
+ es_fclose (infp); infp = NULL;
+ es_fclose (extrafp); extrafp = NULL;
+ es_fclose (outfp); outfp = NULL;
+ es_fclose (errfp); errfp = NULL;
+
+ err = gnupg_wait_process (pgmname, pid, 1, NULL);
+ pid = (pid_t)(-1);
+
+ leave:
+ if (err && pid != (pid_t) -1)
+ gnupg_kill_process (pid);
+
+ es_fclose (infp);
+ es_fclose (extrafp);
+ es_fclose (outfp);
+ es_fclose (errfp);
+ if (pid != (pid_t)(-1))
+ gnupg_wait_process (pgmname, pid, 1, NULL);
+ gnupg_release_process (pid);
+
+ copy_buffer_shred (cpbuf_in);
+ xfree (cpbuf_in);
+ copy_buffer_shred (cpbuf_out);
+ xfree (cpbuf_out);
+ copy_buffer_shred (cpbuf_extra);
+ xfree (cpbuf_extra);
+ xfree (fderrstate.buffer);
+ return err;
+}
+
+
+/* A dummy free function to pass to 'es_mopen'. */
+static void
+nop_free (void *ptr)
+{
+ (void) ptr;
+}
+
+/* Run the program PGMNAME with the command line arguments given in
+ the NULL terminates array ARGV. If INPUT_STRING is not NULL it
+ will be fed to stdin of the process. stderr is logged using
+ log_info and the process' stdout is returned in a newly malloced
+ buffer RESULT with the length stored at RESULTLEN if not given as
+ NULL. A hidden Nul is appended to the output. On error NULL is
+ stored at RESULT, a diagnostic is printed, and an error code
+ returned. */
+gpg_error_t
+gnupg_exec_tool (const char *pgmname, const char *argv[],
+ const char *input_string,
+ char **result, size_t *resultlen)
+{
+ gpg_error_t err;
+ estream_t input = NULL;
+ estream_t output;
+ size_t len;
+ size_t nread;
+
+ *result = NULL;
+ if (resultlen)
+ *resultlen = 0;
+
+ if (input_string)
+ {
+ len = strlen (input_string);
+ input = es_mopen ((char *) input_string, len, len,
+ 0 /* don't grow */, NULL, nop_free, "rb");
+ if (! input)
+ return my_error_from_syserror ();
+ }
+
+ output = es_fopenmem (0, "wb");
+ if (! output)
+ {
+ err = my_error_from_syserror ();
+ goto leave;
+ }
+
+ err = gnupg_exec_tool_stream (pgmname, argv, input, NULL, output, NULL, NULL);
+ if (err)
+ goto leave;
+
+ len = es_ftello (output);
+ err = es_fseek (output, 0, SEEK_SET);
+ if (err)
+ goto leave;
+
+ *result = xtrymalloc (len + 1);
+ if (!*result)
+ {
+ err = my_error_from_syserror ();
+ goto leave;
+ }
+
+ if (len)
+ {
+ if (es_read (output, *result, len, &nread))
+ {
+ err = my_error_from_syserror ();
+ goto leave;
+ }
+ if (nread != len)
+ log_fatal ("%s: short read from memstream\n", __func__);
+ }
+ (*result)[len] = 0;
+
+ if (resultlen)
+ *resultlen = len;
+
+ leave:
+ es_fclose (input);
+ es_fclose (output);
+ if (err)
+ {
+ xfree (*result);
+ *result = NULL;
+ }
+ return err;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-20 15:16:23 +0000