File: [local] / src / usr.bin / rsync / ids.c (download)
Revision 1.4, Tue Feb 12 19:39:57 2019 UTC (5 years, 3 months ago) by benno
Branch: MAIN
Changes since 1.3: +8 -8 lines
whitespace and knf
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/* $Id: ids.c,v 1.4 2019/02/12 19:39:57 benno Exp $ */
/*
* Copyright (c) 2019 Kristaps Dzonsons <kristaps@bsd.lv>
*
* 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.
*/
#include <assert.h>
#include <grp.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "extern.h"
/*
* Free a list of struct ident previously allocated with idents_gid_add().
* Does nothing if the pointer is NULL.
*/
void
idents_free(struct ident *p, size_t sz)
{
size_t i;
if (p == NULL)
return;
for (i = 0; i < sz; i++)
free(p[i].name);
free(p);
}
/*
* Given a list of files with the groups as set by the sender, re-assign
* the groups from the list of remapped group identifiers.
* Don't ever remap group wheel.
*/
void
idents_gid_assign(struct sess *sess, struct flist *fl, size_t flsz,
const struct ident *gids, size_t gidsz)
{
size_t i, j;
for (i = 0; i < flsz; i++) {
if (0 == fl[i].st.gid)
continue;
for (j = 0; j < gidsz; j++)
if ((int32_t)fl[i].st.gid == gids[j].id)
break;
assert(j < gidsz);
fl[i].st.gid = gids[j].mapped;
}
}
/*
* Given a list of groups from the remote host, fill in our local
* identifiers of the same names.
* Use the remote numeric identifier if we can't find the group OR the
* group has identifier zero.
* FIXME: what happens if we don't find the local group (we should
* really warn about this), but the remote group identifier maps into a
* different group name for us?
* These are pretty unexpected things for rsync to do.
* Another FIXME because we shouldn't let that happen even though the
* reference rsync does.
*/
void
idents_gid_remap(struct sess *sess, struct ident *gids, size_t gidsz)
{
size_t i;
struct group *grp;
for (i = 0; i < gidsz; i++) {
assert(gids[i].id != 0);
/*
* (1) Empty names inherit.
* (2) Unknown group names inherit.
* (3) Group wheel inherits.
* (4) Otherwise, use the local identifier.
*/
if (gids[i].name[0] == '\0')
gids[i].mapped = gids[i].id;
else if ((grp = getgrnam(gids[i].name)) == NULL)
gids[i].mapped = gids[i].id;
else if (grp->gr_gid == 0)
gids[i].mapped = gids[i].id;
else
gids[i].mapped = grp->gr_gid;
LOG4(sess, "remapped group %s: %" PRId32 " -> %" PRId32,
gids[i].name, gids[i].id, gids[i].mapped);
}
}
/*
* If "gid" is not part of the list of known groups, add it.
* This also verifies that the group name isn't too long.
* Does nothing with group zero.
* Return zero on failure, non-zero on success.
*/
int
idents_gid_add(struct sess *sess, struct ident **gids, size_t *gidsz, gid_t gid)
{
struct group *grp;
size_t i, sz;
void *pp;
if (gid == 0)
return 1;
for (i = 0; i < *gidsz; i++)
if ((*gids)[i].id == (int32_t)gid)
return 1;
/*
* Look us up in /etc/group.
* Make sure that the group name length is sane: we transmit it
* using a single byte.
*/
assert(i == *gidsz);
if ((grp = getgrgid(gid)) == NULL) {
ERR(sess, "%u: unknown gid", gid);
return 0;
} else if ((sz = strlen(grp->gr_name)) > UINT8_MAX) {
ERRX(sess, "%u: group name too long: %s", gid, grp->gr_name);
return 0;
} else if (sz == 0) {
ERRX(sess, "%u: group name zero-length", gid);
return 0;
}
/* Add the group to the array. */
pp = reallocarray(*gids, *gidsz + 1, sizeof(struct ident));
if (pp == NULL) {
ERR(sess, "reallocarray");
return 0;
}
*gids = pp;
(*gids)[*gidsz].id = gid;
(*gids)[*gidsz].name = strdup(grp->gr_name);
if (NULL == (*gids)[*gidsz].name) {
ERR(sess, "strdup");
return 0;
}
LOG4(sess, "adding group to list: %s (%u)",
(*gids)[*gidsz].name, (*gids)[*gidsz].id);
(*gidsz)++;
return 1;
}
/*
* Send a list of struct ident.
* See idents_recv().
* We should only do this if we're preserving gids/uids.
* Return zero on failure, non-zero on success.
*/
int
idents_send(struct sess *sess,
int fd, const struct ident *ids, size_t idsz)
{
size_t i, sz;
for (i = 0; i < idsz; i++) {
assert(ids[i].name != NULL);
assert(ids[i].id != 0);
sz = strlen(ids[i].name);
assert(sz > 0 && sz <= UINT8_MAX);
if (!io_write_int(sess, fd, ids[i].id)) {
ERRX1(sess, "io_write_int");
return 0;
} else if (!io_write_byte(sess, fd, sz)) {
ERRX1(sess, "io_write_byte");
return 0;
} else if (!io_write_buf(sess, fd, ids[i].name, sz)) {
ERRX1(sess, "io_write_byte");
return 0;
}
}
if (!io_write_int(sess, fd, 0)) {
ERRX1(sess, "io_write_int");
return 0;
}
return 1;
}
/*
* Receive a list of struct ident.
* See idents_send().
* We should only do this if we're preserving gids/uids.
* Return zero on failure, non-zero on success.
*/
int
idents_recv(struct sess *sess,
int fd, struct ident **ids, size_t *idsz)
{
int32_t id;
uint8_t sz;
void *pp;
for (;;) {
if (!io_read_int(sess, fd, &id)) {
ERRX1(sess, "io_read_int");
return 0;
} else if (id == 0)
break;
pp = reallocarray(*ids,
*idsz + 1, sizeof(struct ident));
if (pp == NULL) {
ERR(sess, "reallocarray");
return 0;
}
*ids = pp;
memset(&(*ids)[*idsz], 0, sizeof(struct ident));
/*
* When reading the size, warn if we get a group size of
* zero.
* The spec doesn't allow this, but we might have a
* noncomformant or adversarial sender.
*/
if (!io_read_byte(sess, fd, &sz)) {
ERRX1(sess, "io_read_byte");
return 0;
} else if (0 == sz)
WARNX(sess, "zero-length group name "
"in group list");
(*ids)[*idsz].id = id;
(*ids)[*idsz].name = calloc(sz + 1, 1);
if ((*ids)[*idsz].name == NULL) {
ERR(sess, "calloc");
return 0;
}
if (!io_read_buf(sess, fd, (*ids)[*idsz].name, sz)) {
ERRX1(sess, "io_read_buf");
return 0;
}
(*idsz)++;
}
return 1;
}