libutil: Implement group file utilities
authorJohn Marino <draco@marino.st>
Sat, 3 Nov 2012 15:19:12 +0000 (16:19 +0100)
committerJohn Marino <draco@marino.st>
Sat, 3 Nov 2012 15:45:28 +0000 (16:45 +0100)
Taken from FreeBSD's libutil

lib/libutil/Makefile
lib/libutil/gr_util.c [new file with mode: 0644]
lib/libutil/libutil.h

index defb463..97d5370 100644 (file)
@@ -12,6 +12,7 @@ SRCS= flopen.c login.c login_tty.c logout.c logwtmp.c logwtmpx.c pty.c \
        realhostname.c fparseln.c stub.c pidfile.c trimdomain.c \
        dehumanize_number.c humanize_number.c humanize_unsigned.c pw_util.c \
        efun.c getmntopts.c
+SRCS+= gr_util.c
 
 INCS=  libutil.h login_cap.h
 INCSLINKS=libutil.h ${INCLUDEDIR}/util.h
diff --git a/lib/libutil/gr_util.c b/lib/libutil/gr_util.c
new file mode 100644 (file)
index 0000000..4d035d6
--- /dev/null
@@ -0,0 +1,545 @@
+/*-
+ * Copyright (c) 2008 Sean C. Farley <scf@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer,
+ *    without modification, immediately at the beginning of the file.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#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>
+
+struct group_storage {
+       struct group     gr;
+       char            *members[];
+};
+
+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 const char group_line_format[] = "%s:%s:%ju:";
+
+/*
+ * 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 = open(group_file, O_RDONLY, 0);
+               if (lockfd < 0 || fcntl(lockfd, F_SETFD, 1) == -1)
+                       err(1, "%s", group_file);
+               if (flock(lockfd, LOCK_EX|LOCK_NB) == -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 = mkstemp(tempname)) == -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[8192], *end, *line, *p, *q, *r, t;
+       struct group *fgr;
+       const struct group *sgr;
+       size_t len;
+       int eof, readlen;
+
+       sgr = gr;
+       if (gr == NULL) {
+               line = NULL;
+               if (old_gr == NULL)
+                       return (-1);
+               sgr = old_gr;
+       } else if ((line = gr_make(gr)) == NULL)
+               return (-1);
+
+       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;
+                       if ((size_t)(q - p) >= sizeof(buf)) {
+                               warnx("group line too long");
+                               errno = EINVAL; /* hack */
+                               goto err;
+                       }
+                       if (p < end) {
+                               q = memmove(buf, p, end -p);
+                               end -= p - buf;
+                       } else {
+                               p = q = end = buf;
+                       }
+                       readlen = read(ffd, end, sizeof(buf) - (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 < (ssize_t)sizeof(buf)) {
+                               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, sizeof(buf));
+                       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:
+       if (line != NULL)
+               free(line);
+       return (0);
+ err:
+       if (line != NULL)
+               free(line);
+       return (-1);
+}
+
+/*
+ * Regenerate the group file
+ */
+int
+gr_mkdb(void)
+{
+       return (rename(tempname, group_file));
+}
+
+/*
+ * Clean up. Preserver 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_name != gr2->gr_name)
+                       return (false);
+       } else if (strcmp(gr1->gr_name, gr2->gr_name) != 0)
+               return (false);
+       if (gr1->gr_passwd == NULL || gr2->gr_passwd == NULL) {
+               if (gr1->gr_passwd != gr2->gr_passwd)
+                       return (false);
+       } else if (strcmp(gr1->gr_passwd, gr2->gr_passwd) != 0)
+               return (false);
+       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)
+                               return (false);
+               }
+
+               /* Check that group2 does not have more members than group1. */
+               if (gr2->gr_mem[gr1_ndx] != NULL)
+                       return (false);
+       }
+
+       return (true);
+}
+
+/*
+ * Make a group line out of a struct group.
+ */
+char *
+gr_make(const struct group *gr)
+{
+       char *line;
+       size_t line_size;
+       int ndx;
+
+       /* Calculate the length of the group line. */
+       line_size = snprintf(NULL, 0, group_line_format, gr->gr_name,
+           gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1;
+       if (gr->gr_mem != NULL) {
+               for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
+                       line_size += strlen(gr->gr_mem[ndx]) + 1;
+               if (ndx > 0)
+                       line_size--;
+       }
+
+       /* Create the group line and fill it. */
+       if ((line = malloc(line_size)) == NULL)
+               return (NULL);
+       snprintf(line, line_size, group_line_format, gr->gr_name, gr->gr_passwd,
+           (uintmax_t)gr->gr_gid);
+       if (gr->gr_mem != NULL)
+               for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
+                       strcat(line, gr->gr_mem[ndx]);
+                       if (gr->gr_mem[ndx + 1] != NULL)
+                               strcat(line, ",");
+               }
+
+       return (line);
+}
+
+/*
+ * Duplicate a struct group.
+ */
+struct group *
+gr_dup(const struct group *gr)
+{
+       char *dst;
+       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;
+
+       /* Create new group and copy old group into it. */
+       if ((gs = calloc(1, len)) == NULL)
+               return (NULL);
+       dst = (char *)&gs->members[num_mem + 1];
+       if (gr->gr_name != NULL) {
+               gs->gr.gr_name = dst;
+               dst = stpcpy(gs->gr.gr_name, gr->gr_name) + 1;
+       }
+       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;
+       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;
+               }
+               gs->gr.gr_mem[ndx] = NULL;
+       }
+
+       return (&gs->gr);
+}
+
+/*
+ * Scan a line and place it into a group structure.
+ */
+static bool
+__gr_scan(char *line, struct group *gr)
+{
+       char *loc;
+       int ndx;
+
+       /* Assign non-member information to structure. */
+       gr->gr_name = line;
+       if ((loc = strchr(line, ':')) == NULL)
+               return (false);
+       *loc = '\0';
+       gr->gr_passwd = loc + 1;
+       if (*gr->gr_passwd == ':')
+               *gr->gr_passwd = '\0';
+       else {
+               if ((loc = strchr(loc + 1, ':')) == NULL)
+                       return (false);
+               *loc = '\0';
+       }
+       if (sscanf(loc + 1, "%u", &gr->gr_gid) != 1)
+               return (false);
+
+       /* Assign member information to structure. */
+       if ((loc = strchr(loc + 1, ':')) == NULL)
+               return (false);
+       line = loc + 1;
+       gr->gr_mem = NULL;
+       ndx = 0;
+       do {
+               gr->gr_mem = reallocf(gr->gr_mem, sizeof(*gr->gr_mem) *
+                   (ndx + 1));
+               if (gr->gr_mem == NULL)
+                       return (false);
+
+               /* Skip locations without members (i.e., empty string). */
+               do {
+                       gr->gr_mem[ndx] = strsep(&line, ",");
+               } while (gr->gr_mem[ndx] != NULL && *gr->gr_mem[ndx] == '\0');
+       } while (gr->gr_mem[ndx++] != NULL);
+
+       return (true);
+}
+
+/*
+ * Create a struct group from a line.
+ */
+struct group *
+gr_scan(const char *line)
+{
+       struct group gr;
+       char *line_copy;
+       struct group *new_gr;
+
+       if ((line_copy = strdup(line)) == NULL)
+               return (NULL);
+       if (!__gr_scan(line_copy, &gr)) {
+               free(line_copy);
+               return (NULL);
+       }
+       new_gr = gr_dup(&gr);
+       free(line_copy);
+       if (gr.gr_mem != NULL)
+               free(gr.gr_mem);
+
+       return (new_gr);
+}
index 38f5dba..1688ea4 100644 (file)
@@ -33,7 +33,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $FreeBSD: src/lib/libutil/libutil.h,v 1.26.2.3 2000/11/22 03:49:49 murray Exp $
+ * $FreeBSD$
  */
 
 #ifndef _LIBUTIL_H_
 #define        _PWSCAN_WARN    0x02
 #endif
 
-#define PROPERTY_MAX_NAME      64
-#define PROPERTY_MAX_VALUE     512
+#define        PROPERTY_MAX_NAME       64
+#define        PROPERTY_MAX_VALUE      512
 
-/* for properties.c */
+/* For properties.c. */
 typedef struct _property {
        struct _property *next;
-       char *name;
-       char *value;
+       char    *name;
+       char    *value;
 } *properties;
 
-/* Avoid pulling in all the include files for no need */
+/* Avoid pulling in all the include files for no need. */
+struct in_addr;
+struct sockaddr;
 struct termios;
 struct winsize;
 struct utmp;
 struct utmpx;
-struct in_addr;
-struct sockaddr;
 
 __BEGIN_DECLS
 int    flopen(const char *, int, ...);
@@ -98,8 +98,10 @@ char   *fparseln(FILE *, size_t *, size_t *, const char[3], int);
 #endif
 
 #ifdef _PWD_H_
-int    pw_copy(int _ffd, int _tfd, const struct passwd *_pw, struct passwd *_old_pw);
-struct passwd *pw_dup(const struct passwd *_pw);
+int    pw_copy(int _ffd, int _tfd, const struct passwd *_pw,
+           struct passwd *_old_pw);
+struct passwd
+       *pw_dup(const struct passwd *_pw);
 int    pw_edit(int _notsetuid);
 int    pw_equal(const struct passwd *_pw1, const struct passwd *_pw2);
 void   pw_fini(void);
@@ -107,11 +109,29 @@ int       pw_init(const char *_dir, const char *_master);
 char   *pw_make(const struct passwd *_pw);
 int    pw_mkdb(const char *_user);
 int    pw_lock(void);
-struct passwd *pw_scan(const char *_line, int _flags);
-const char *pw_tempname(void);
+struct passwd *
+       pw_scan(const char *_line, int _flags);
+const char *
+       pw_tempname(void);
 int    pw_tmp(int _mfd);
 #endif
 
+#ifdef _GRP_H_
+int    gr_copy(int __ffd, int _tfd, const struct group *_gr,
+           struct group *_old_gr);
+struct group *
+       gr_dup(const struct group *_gr);
+int    gr_equal(const struct group *_gr1, const struct group *_gr2);
+void   gr_fini(void);
+int    gr_init(const char *_dir, const char *_master);
+int    gr_lock(void);
+char   *gr_make(const struct group *_gr);
+int    gr_mkdb(void);
+struct group *
+       gr_scan(const char *_line);
+int    gr_tmp(int _mdf);
+#endif
+
 /* Error checked functions */
 void           (*esetfunc(void (*)(int, const char *, ...)))
                (int, const char *, ...);
@@ -126,22 +146,6 @@ int                easprintf(char ** __restrict, const char * __restrict, ...)
                __printflike(2, 3);
 __END_DECLS
 
-#define UU_LOCK_INUSE (1)
-#define UU_LOCK_OK (0)
-#define UU_LOCK_OPEN_ERR (-1)
-#define UU_LOCK_READ_ERR (-2)
-#define UU_LOCK_CREAT_ERR (-3)
-#define UU_LOCK_WRITE_ERR (-4)
-#define UU_LOCK_LINK_ERR (-5)
-#define UU_LOCK_TRY_ERR (-6)
-#define UU_LOCK_OWNER_ERR (-7)
-
-/* return values from realhostname() */
-#define HOSTNAME_FOUND         (0)
-#define HOSTNAME_INCORRECTNAME (1)
-#define HOSTNAME_INVALIDADDR   (2)
-#define HOSTNAME_INVALIDNAME   (3)
-
 /* fparseln(3) */
 #define        FPARSELN_UNESCESC       0x01
 #define        FPARSELN_UNESCCONT      0x02
@@ -149,16 +153,36 @@ __END_DECLS
 #define        FPARSELN_UNESCREST      0x08
 #define        FPARSELN_UNESCALL       0x0f
 
-/* pw_scan() */
-#define PWSCAN_MASTER          0x01
-#define PWSCAN_WARN            0x02
-
-/* humanize_number(3) */ 
-#define HN_DECIMAL             0x01 
-#define HN_NOSPACE             0x02 
-#define HN_B                   0x04 
-#define HN_DIVISOR_1000                0x08 
-#define HN_GETSCALE            0x10 
-#define HN_AUTOSCALE           0x20 
+/* Values for humanize_number(3)'s flags parameter. */
+#define        HN_DECIMAL              0x01
+#define        HN_NOSPACE              0x02
+#define        HN_B                    0x04
+#define        HN_DIVISOR_1000         0x08
+#define        HN_IEC_PREFIXES         0x10
+
+/* Values for humanize_number(3)'s scale parameter. */
+#define        HN_GETSCALE             0x10
+#define        HN_AUTOSCALE            0x20
+
+/* Return values from realhostname(). */
+#define        HOSTNAME_FOUND          0
+#define        HOSTNAME_INCORRECTNAME  1
+#define        HOSTNAME_INVALIDADDR    2
+#define        HOSTNAME_INVALIDNAME    3
+
+/* Flags for pw_scan(). */
+#define        PWSCAN_MASTER           0x01
+#define        PWSCAN_WARN             0x02
+
+/* Return values from uu_lock(). */
+#define        UU_LOCK_INUSE           1
+#define        UU_LOCK_OK              0
+#define        UU_LOCK_OPEN_ERR        (-1)
+#define        UU_LOCK_READ_ERR        (-2)
+#define        UU_LOCK_CREAT_ERR       (-3)
+#define        UU_LOCK_WRITE_ERR       (-4)
+#define        UU_LOCK_LINK_ERR        (-5)
+#define        UU_LOCK_TRY_ERR         (-6)
+#define        UU_LOCK_OWNER_ERR       (-7)
 
 #endif /* !_LIBUTIL_H_ */