Adding upstream version 1.8.27.upstream/1.8.27upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 222 insertions, 0 deletions

diff --git a/src/preserve_fds.c b/src/preserve_fds.c
new file mode 100644
index 0000000..1de01ad
--- /dev/null
+++ b/src/preserve_fds.c
@@ -0,0 +1,222 @@
+/*
+ * Copyright (c) 2013-2015 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/types.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif /* HAVE_STRING_H */
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif /* HAVE_STRINGS_H */
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+
+#include "sudo.h"
+
+/*
+ * Add an fd to preserve.
+ */
+int
+add_preserved_fd(struct preserved_fd_list *pfds, int fd)
+{
+    struct preserved_fd *pfd, *pfd_new;
+    debug_decl(add_preserved_fd, SUDO_DEBUG_UTIL)
+
+    pfd_new = malloc(sizeof(*pfd));
+    if (pfd_new == NULL)
+	sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+    pfd_new->lowfd = fd;
+    pfd_new->highfd = fd;
+    pfd_new->flags = fcntl(fd, F_GETFD);
+    if (pfd_new->flags == -1) {
+	free(pfd_new);
+	debug_return_int(-1);
+    }
+
+    TAILQ_FOREACH(pfd, pfds, entries) {
+	if (fd == pfd->highfd) {
+	    /* already preserved */
+	    sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+		"fd %d already preserved", fd);
+	    free(pfd_new);
+	    pfd_new = NULL;
+	    break;
+	}
+	if (fd < pfd->highfd) {
+	    TAILQ_INSERT_BEFORE(pfd, pfd_new, entries);
+	    sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+		"preserving fd %d", fd);
+	    pfd_new = NULL;
+	    break;
+	}
+    }
+    if (pfd_new != NULL) {
+	TAILQ_INSERT_TAIL(pfds, pfd_new, entries);
+	sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+	    "preserving fd %d", fd);
+    }
+
+    debug_return_int(0);
+}
+
+/*
+ * Close all descriptors, startfd and higher except those listed
+ * in pfds.
+ */
+void
+closefrom_except(int startfd, struct preserved_fd_list *pfds)
+{
+    int fd, lastfd = -1;
+    struct preserved_fd *pfd, *pfd_next;
+    unsigned char *fdbits;
+    debug_decl(closefrom_except, SUDO_DEBUG_UTIL)
+
+    /* First, relocate preserved fds to be as contiguous as possible.  */
+    TAILQ_FOREACH_REVERSE_SAFE(pfd, pfds, preserved_fd_list, entries, pfd_next) {
+	if (pfd->highfd < startfd)
+	    continue;
+	fd = dup(pfd->highfd);
+	if (fd == -1) {
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO,
+		"dup %d", pfd->highfd);
+	    if (errno == EBADF) {
+		TAILQ_REMOVE(pfds, pfd, entries);
+		continue;
+	    }
+	    /* NOTE: still need to adjust lastfd below with unchanged lowfd. */
+	} else if (fd < pfd->highfd) {
+	    sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+		"dup %d -> %d", pfd->highfd, pfd->lowfd);
+	    sudo_debug_update_fd(pfd->highfd, pfd->lowfd);
+	    pfd->lowfd = fd;
+	    fd = pfd->highfd;
+	}
+	if (fd != -1)
+	    (void) close(fd);
+
+	if (pfd->lowfd > lastfd)
+	    lastfd = pfd->lowfd;	/* highest (relocated) preserved fd */
+    }
+
+    if (lastfd == -1) {
+	/* No fds to preserve. */
+	sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+	    "closefrom(%d)", startfd);
+	closefrom(startfd);
+	debug_return;
+    }
+
+    /* Create bitmap of preserved (relocated) fds.  */
+    fdbits = calloc((lastfd + NBBY) / NBBY, 1);
+    if (fdbits == NULL)
+	sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+    TAILQ_FOREACH(pfd, pfds, entries) {
+	sudo_setbit(fdbits, pfd->lowfd);
+    }
+
+    /*
+     * Close any unpreserved fds [startfd,lastfd]
+     */
+    for (fd = startfd; fd <= lastfd; fd++) {
+	if (!sudo_isset(fdbits, fd)) {
+	    sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+		"closing fd %d", fd);
+#ifdef __APPLE__
+	    /* Avoid potential libdispatch crash when we close its fds. */
+	    (void) fcntl(fd, F_SETFD, FD_CLOEXEC);
+#else
+	    (void) close(fd);
+#endif
+	}
+    }
+    free(fdbits);
+
+    /* Let closefrom() do the rest for us. */
+    if (lastfd + 1 > startfd)
+	startfd = lastfd + 1;
+    sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+	"closefrom(%d)", startfd);
+    closefrom(startfd);
+
+    /* Restore preserved fds and set flags. */
+    TAILQ_FOREACH_REVERSE(pfd, pfds, preserved_fd_list, entries) {
+	if (pfd->lowfd != pfd->highfd) {
+	    if (dup2(pfd->lowfd, pfd->highfd) == -1) {
+		sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		    "dup2(%d, %d): %s", pfd->lowfd, pfd->highfd,
+		    strerror(errno));
+	    } else {
+		sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+		    "dup2(%d, %d)", pfd->lowfd, pfd->highfd);
+	    }
+	    if (fcntl(pfd->highfd, F_SETFD, pfd->flags) == -1) {
+		sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		    "fcntl(%d, F_SETFD, %d): %s", pfd->highfd,
+		    pfd->flags, strerror(errno));
+	    } else {
+		sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,
+		    "fcntl(%d, F_SETFD, %d)", pfd->highfd, pfd->flags);
+	    }
+	    sudo_debug_update_fd(pfd->lowfd, pfd->highfd);
+	    (void) close(pfd->lowfd);
+	    pfd->lowfd = pfd->highfd;
+	}
+    }
+    debug_return;
+}
+
+/*
+ * Parse a comma-separated list of fds and add them to preserved_fds.
+ */
+void
+parse_preserved_fds(struct preserved_fd_list *pfds, const char *fdstr)
+{
+    const char *cp = fdstr;
+    long lval;
+    char *ep;
+    debug_decl(parse_preserved_fds, SUDO_DEBUG_UTIL)
+
+    do {
+	errno = 0;
+	lval = strtol(cp, &ep, 10);
+	if (ep == cp || (*ep != ',' && *ep != '\0')) {
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"unable to parse fd string %s", cp);
+	    break;
+	}
+	if ((errno == ERANGE && lval == LONG_MAX) || lval < 0 || lval > INT_MAX) {
+	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"range error parsing fd string %s", cp);
+	} else {
+	    add_preserved_fd(pfds, (int)lval);
+	}
+	cp = ep + 1;
+    } while (*ep != '\0');
+
+    debug_return;
+}