/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
* Copyright (c) 2008 Sean C. Farley <scf@FreeBSD.org>
* All rights reserved.
*
__FBSDID("$FreeBSD$");
#include <sys/param.h>
+#include <sys/errno.h>
+#include <sys/stat.h>
+#include <ctype.h>
+#include <err.h>
+#include <fcntl.h>
#include <grp.h>
#include <inttypes.h>
#include <libutil.h>
+#include <paths.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <unistd.h>
+
+static int lockfd = -1;
+static char group_dir[PATH_MAX];
+static char group_file[PATH_MAX];
+static char tempname[PATH_MAX];
+static int initialized;
+static size_t grmemlen(const struct group *, const char *, int *);
+static struct group *grcopy(const struct group *gr, char *mem, const char *, int ndx);
+
+/*
+ * Initialize statics
+ */
+int
+gr_init(const char *dir, const char *group)
+{
+
+ if (dir == NULL) {
+ strcpy(group_dir, _PATH_ETC);
+ } else {
+ if (strlen(dir) >= sizeof(group_dir)) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ strcpy(group_dir, dir);
+ }
+
+ if (group == NULL) {
+ if (dir == NULL) {
+ strcpy(group_file, _PATH_GROUP);
+ } else if (snprintf(group_file, sizeof(group_file), "%s/group",
+ group_dir) > (int)sizeof(group_file)) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ } else {
+ if (strlen(group) >= sizeof(group_file)) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ strcpy(group_file, group);
+ }
+
+ initialized = 1;
+ return (0);
+}
+
+/*
+ * Lock the group file
+ */
+int
+gr_lock(void)
+{
+ if (*group_file == '\0')
+ return (-1);
+
+ for (;;) {
+ struct stat st;
+
+ lockfd = flopen(group_file, O_RDONLY|O_NONBLOCK|O_CLOEXEC, 0);
+ if (lockfd == -1) {
+ if (errno == EWOULDBLOCK) {
+ errx(1, "the group file is busy");
+ } else {
+ err(1, "could not lock the group file: ");
+ }
+ }
+ if (fstat(lockfd, &st) == -1)
+ err(1, "fstat() failed: ");
+ if (st.st_nlink != 0)
+ break;
+ close(lockfd);
+ lockfd = -1;
+ }
+ return (lockfd);
+}
+
+/*
+ * Create and open a presmuably safe temp file for editing group data
+ */
+int
+gr_tmp(int mfd)
+{
+ char buf[8192];
+ ssize_t nr;
+ const char *p;
+ int tfd;
+
+ if (*group_file == '\0')
+ return (-1);
+ if ((p = strrchr(group_file, '/')))
+ ++p;
+ else
+ p = group_file;
+ if (snprintf(tempname, sizeof(tempname), "%.*sgroup.XXXXXX",
+ (int)(p - group_file), group_file) >= (int)sizeof(tempname)) {
+ errno = ENAMETOOLONG;
+ return (-1);
+ }
+ if ((tfd = mkostemp(tempname, 0)) == -1)
+ return (-1);
+ if (mfd != -1) {
+ while ((nr = read(mfd, buf, sizeof(buf))) > 0)
+ if (write(tfd, buf, (size_t)nr) != nr)
+ break;
+ if (nr != 0) {
+ unlink(tempname);
+ *tempname = '\0';
+ close(tfd);
+ return (-1);
+ }
+ }
+ return (tfd);
+}
+
+/*
+ * Copy the group file from one descriptor to another, replacing, deleting
+ * or adding a single record on the way.
+ */
+int
+gr_copy(int ffd, int tfd, const struct group *gr, struct group *old_gr)
+{
+ char *buf, *end, *line, *p, *q, *r, *tmp;
+ struct group *fgr;
+ const struct group *sgr;
+ size_t len, size;
+ int eof, readlen;
+ char t;
+
+ if (old_gr == NULL && gr == NULL)
+ return(-1);
+
+ sgr = old_gr;
+ /* deleting a group */
+ if (gr == NULL) {
+ line = NULL;
+ } else {
+ if ((line = gr_make(gr)) == NULL)
+ return (-1);
+ }
+
+ /* adding a group */
+ if (sgr == NULL)
+ sgr = gr;
+
+ /* initialize the buffer */
+ if ((buf = malloc(size = 1024)) == NULL)
+ goto err;
+
+ eof = 0;
+ len = 0;
+ p = q = end = buf;
+ for (;;) {
+ /* find the end of the current line */
+ for (p = q; q < end && *q != '\0'; ++q)
+ if (*q == '\n')
+ break;
+
+ /* if we don't have a complete line, fill up the buffer */
+ if (q >= end) {
+ if (eof)
+ break;
+ while ((size_t)(q - p) >= size) {
+ if ((tmp = reallocarray(buf, 2, size)) == NULL) {
+ warnx("group line too long");
+ goto err;
+ }
+ p = tmp + (p - buf);
+ q = tmp + (q - buf);
+ end = tmp + (end - buf);
+ buf = tmp;
+ size = size * 2;
+ }
+ if (p < end) {
+ q = memmove(buf, p, end -p);
+ end -= p - buf;
+ } else {
+ p = q = end = buf;
+ }
+ readlen = read(ffd, end, size - (end - buf));
+ if (readlen == -1)
+ goto err;
+ else
+ len = (size_t)readlen;
+ if (len == 0 && p == buf)
+ break;
+ end += len;
+ len = end - buf;
+ if (len < size) {
+ eof = 1;
+ if (len > 0 && buf[len -1] != '\n')
+ ++len, *end++ = '\n';
+ }
+ continue;
+ }
+
+ /* is it a blank line or a comment? */
+ for (r = p; r < q && isspace(*r); ++r)
+ /* nothing */;
+ if (r == q || *r == '#') {
+ /* yep */
+ if (write(tfd, p, q -p + 1) != q - p + 1)
+ goto err;
+ ++q;
+ continue;
+ }
+
+ /* is it the one we're looking for? */
+
+ t = *q;
+ *q = '\0';
+
+ fgr = gr_scan(r);
+
+ /* fgr is either a struct group for the current line,
+ * or NULL if the line is malformed.
+ */
+
+ *q = t;
+ if (fgr == NULL || fgr->gr_gid != sgr->gr_gid) {
+ /* nope */
+ if (fgr != NULL)
+ free(fgr);
+ if (write(tfd, p, q - p + 1) != q - p + 1)
+ goto err;
+ ++q;
+ continue;
+ }
+ if (old_gr && !gr_equal(fgr, old_gr)) {
+ warnx("entry inconsistent");
+ free(fgr);
+ errno = EINVAL; /* hack */
+ goto err;
+ }
+ free(fgr);
+
+ /* it is, replace or remove it */
+ if (line != NULL) {
+ len = strlen(line);
+ if (write(tfd, line, len) != (int) len)
+ goto err;
+ } else {
+ /* when removed, avoid the \n */
+ q++;
+ }
+ /* we're done, just copy the rest over */
+ for (;;) {
+ if (write(tfd, q, end - q) != end - q)
+ goto err;
+ q = buf;
+ readlen = read(ffd, buf, size);
+ if (readlen == 0)
+ break;
+ else
+ len = (size_t)readlen;
+ if (readlen == -1)
+ goto err;
+ end = buf + len;
+ }
+ goto done;
+ }
+
+ /* if we got here, we didn't find the old entry */
+ if (line == NULL) {
+ errno = ENOENT;
+ goto err;
+ }
+ len = strlen(line);
+ if ((size_t)write(tfd, line, len) != len ||
+ write(tfd, "\n", 1) != 1)
+ goto err;
+ done:
+ free(line);
+ free(buf);
+ return (0);
+ err:
+ free(line);
+ free(buf);
+ return (-1);
+}
+
+/*
+ * Regenerate the group file
+ */
+int
+gr_mkdb(void)
+{
+ int fd;
+
+ if (chmod(tempname, 0644) != 0)
+ return (-1);
+
+ if (rename(tempname, group_file) != 0)
+ return (-1);
+
+ /*
+ * Make sure new group file is safe on disk. To improve performance we
+ * will call fsync() to the directory where file lies
+ */
+ if ((fd = open(group_dir, O_RDONLY|O_DIRECTORY)) == -1)
+ return (-1);
+
+ if (fsync(fd) != 0) {
+ close(fd);
+ return (-1);
+ }
-struct group_storage {
- struct group gr;
- char *members[];
-};
+ close(fd);
+ return(0);
+}
-static const char group_line_format[] = "%s:%s:%ju:";
+/*
+ * Clean up. Preserves errno for the caller's convenience.
+ */
+void
+gr_fini(void)
+{
+ int serrno;
+
+ if (!initialized)
+ return;
+ initialized = 0;
+ serrno = errno;
+ if (*tempname != '\0') {
+ unlink(tempname);
+ *tempname = '\0';
+ }
+ if (lockfd != -1)
+ close(lockfd);
+ errno = serrno;
+}
/*
* Compares two struct group's.
int
gr_equal(const struct group *gr1, const struct group *gr2)
{
- int gr1_ndx;
- int gr2_ndx;
- bool found;
/* Check that the non-member information is the same. */
if (gr1->gr_name == NULL || gr2->gr_name == NULL) {
if (gr1->gr_gid != gr2->gr_gid)
return (false);
- /* Check all members in both groups. */
- if (gr1->gr_mem == NULL || gr2->gr_mem == NULL) {
- if (gr1->gr_mem != gr2->gr_mem)
- return (false);
- } else {
- for (found = false, gr1_ndx = 0; gr1->gr_mem[gr1_ndx] != NULL;
- gr1_ndx++) {
- for (gr2_ndx = 0; gr2->gr_mem[gr2_ndx] != NULL;
- gr2_ndx++)
- if (strcmp(gr1->gr_mem[gr1_ndx],
- gr2->gr_mem[gr2_ndx]) == 0) {
- found = true;
- break;
- }
- if (!found)
+ /*
+ * Check all members in both groups.
+ * getgrnam can return gr_mem with a pointer to NULL.
+ * gr_dup and gr_add strip out this superfluous NULL, setting
+ * gr_mem to NULL for no members.
+ */
+ if (gr1->gr_mem != NULL && gr2->gr_mem != NULL) {
+ int i;
+
+ for (i = 0;
+ gr1->gr_mem[i] != NULL && gr2->gr_mem[i] != NULL; i++) {
+ if (strcmp(gr1->gr_mem[i], gr2->gr_mem[i]) != 0)
return (false);
}
-
- /* Check that group2 does not have more members than group1. */
- if (gr2->gr_mem[gr1_ndx] != NULL)
+ if (gr1->gr_mem[i] != NULL || gr2->gr_mem[i] != NULL)
return (false);
+ } else if (gr1->gr_mem != NULL && gr1->gr_mem[0] != NULL) {
+ return (false);
+ } else if (gr2->gr_mem != NULL && gr2->gr_mem[0] != NULL) {
+ return (false);
}
return (true);
char *
gr_make(const struct group *gr)
{
+ const char *group_line_format = "%s:%s:%ju:";
+ const char *sep;
char *line;
+ char *p;
size_t line_size;
int ndx;
}
/* Create the group line and fill it. */
- if ((line = malloc(line_size)) == NULL)
+ if ((line = p = malloc(line_size)) == NULL)
return (NULL);
- snprintf(line, line_size, group_line_format, gr->gr_name, gr->gr_passwd,
+ p += sprintf(p, group_line_format, gr->gr_name, gr->gr_passwd,
(uintmax_t)gr->gr_gid);
- if (gr->gr_mem != NULL)
+ if (gr->gr_mem != NULL) {
+ sep = "";
for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
- strcat(line, gr->gr_mem[ndx]);
- if (gr->gr_mem[ndx + 1] != NULL)
- strcat(line, ",");
+ p = stpcpy(p, sep);
+ p = stpcpy(p, gr->gr_mem[ndx]);
+ sep = ",";
}
+ }
return (line);
}
struct group *
gr_dup(const struct group *gr)
{
- char *dst;
+ return (gr_add(gr, NULL));
+}
+/*
+ * Add a new member name to a struct group.
+ */
+struct group *
+gr_add(const struct group *gr, const char *newmember)
+{
+ char *mem;
size_t len;
- struct group_storage *gs;
- int ndx;
int num_mem;
- /* Calculate size of the group. */
- len = sizeof(*gs);
- if (gr->gr_name != NULL)
- len += strlen(gr->gr_name) + 1;
- if (gr->gr_passwd != NULL)
- len += strlen(gr->gr_passwd) + 1;
- if (gr->gr_mem != NULL) {
- for (num_mem = 0; gr->gr_mem[num_mem] != NULL; num_mem++)
- len += strlen(gr->gr_mem[num_mem]) + 1;
- len += (num_mem + 1) * sizeof(*gr->gr_mem);
- } else
- num_mem = -1;
-
+ num_mem = 0;
+ len = grmemlen(gr, newmember, &num_mem);
/* Create new group and copy old group into it. */
- if ((gs = calloc(1, len)) == NULL)
+ if ((mem = malloc(len)) == NULL)
return (NULL);
- dst = (char *)&gs->members[num_mem + 1];
+ return (grcopy(gr, mem, newmember, num_mem));
+}
+
+/* It is safer to walk the pointers given at gr_mem since there is no
+ * guarantee the gr_mem + strings are contiguous in the given struct group
+ * but compactify the new group into the following form.
+ *
+ * The new struct is laid out like this in memory. The example given is
+ * for a group with two members only.
+ *
+ * {
+ * (char *name)
+ * (char *passwd)
+ * (int gid)
+ * (gr_mem * newgrp + sizeof(struct group) + sizeof(**)) points to gr_mem area
+ * gr_mem area
+ * (member1 *)
+ * (member2 *)
+ * (NULL)
+ * (name string)
+ * (passwd string)
+ * (member1 string)
+ * (member2 string)
+ * }
+ */
+/*
+ * Copy the contents of a group plus given name to a preallocated group struct
+ */
+static struct group *
+grcopy(const struct group *gr, char *dst, const char *name, int ndx)
+{
+ int i;
+ struct group *newgr;
+
+ newgr = (struct group *)(void *)dst; /* avoid alignment warning */
+ dst += sizeof(*newgr);
+ if (ndx != 0) {
+ newgr->gr_mem = (char **)(void *)(dst); /* avoid alignment warning */
+ dst += (ndx + 1) * sizeof(*newgr->gr_mem);
+ } else
+ newgr->gr_mem = NULL;
if (gr->gr_name != NULL) {
- gs->gr.gr_name = dst;
- dst = stpcpy(gs->gr.gr_name, gr->gr_name) + 1;
- }
+ newgr->gr_name = dst;
+ dst = stpcpy(dst, gr->gr_name) + 1;
+ } else
+ newgr->gr_name = NULL;
if (gr->gr_passwd != NULL) {
- gs->gr.gr_passwd = dst;
- dst = stpcpy(gs->gr.gr_passwd, gr->gr_passwd) + 1;
- }
- gs->gr.gr_gid = gr->gr_gid;
+ newgr->gr_passwd = dst;
+ dst = stpcpy(dst, gr->gr_passwd) + 1;
+ } else
+ newgr->gr_passwd = NULL;
+ newgr->gr_gid = gr->gr_gid;
+ i = 0;
+ /* Original group struct might have a NULL gr_mem */
if (gr->gr_mem != NULL) {
- gs->gr.gr_mem = gs->members;
- for (ndx = 0; ndx < num_mem; ndx++) {
- gs->gr.gr_mem[ndx] = dst;
- dst = stpcpy(gs->gr.gr_mem[ndx], gr->gr_mem[ndx]) + 1;
+ for (; gr->gr_mem[i] != NULL; i++) {
+ newgr->gr_mem[i] = dst;
+ dst = stpcpy(dst, gr->gr_mem[i]) + 1;
}
- gs->gr.gr_mem[ndx] = NULL;
}
+ /* If name is not NULL, newgr->gr_mem is known to be not NULL */
+ if (name != NULL) {
+ newgr->gr_mem[i++] = dst;
+ dst = stpcpy(dst, name) + 1;
+ }
+ /* if newgr->gr_mem is not NULL add NULL marker */
+ if (newgr->gr_mem != NULL)
+ newgr->gr_mem[i] = NULL;
+
+ return (newgr);
+}
- return (&gs->gr);
+/*
+ * Calculate length of a struct group + given name
+ */
+static size_t
+grmemlen(const struct group *gr, const char *name, int *num_mem)
+{
+ size_t len;
+ int i;
+
+ if (gr == NULL)
+ return (0);
+ /* Calculate size of the group. */
+ len = sizeof(*gr);
+ if (gr->gr_name != NULL)
+ len += strlen(gr->gr_name) + 1;
+ if (gr->gr_passwd != NULL)
+ len += strlen(gr->gr_passwd) + 1;
+ i = 0;
+ if (gr->gr_mem != NULL) {
+ for (; gr->gr_mem[i] != NULL; i++) {
+ len += strlen(gr->gr_mem[i]) + 1;
+ len += sizeof(*gr->gr_mem);
+ }
+ }
+ if (name != NULL) {
+ i++;
+ len += strlen(name) + 1;
+ len += sizeof(*gr->gr_mem);
+ }
+ /* Allow for NULL pointer */
+ if (i != 0)
+ len += sizeof(*gr->gr_mem);
+ *num_mem = i;
+ return(len);
}
/*
git.ckatri.com / pw-darwin.git / blobdiff