/* vi: set sw=4 ts=4: */
-/* Copyright (C) 2014 Tito Ragusa <farmatito@tiscali.it>
+/* Copyright (C) 2014 Tito Ragusa <farmatito@tiscali.it>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
* Rewrite of some parts. Main differences are:
*
* 1) the buffer for getpwuid, getgrgid, getpwnam, getgrnam is dynamically
- * allocated and reused by later calls. if ERANGE error pops up it is
- * reallocated to the size of the longest line found so far in the
- * passwd/group files and reused for later calls.
+ * allocated.
* If ENABLE_FEATURE_CLEAN_UP is set the buffers are freed at program
* exit using the atexit function to make valgrind happy.
* 2) the passwd/group files:
* a) must contain the expected number of fields (as per count of field
- * delimeters ":") or we will complain with a error message.
- * b) leading or trailing whitespace in fields is allowed and handled.
- * c) some fields are not allowed to be empty (e.g. username, uid/gid,
- * homedir, shell) and in this case NULL is returned and errno is
- * set to EINVAL. This behaviour could be easily changed by
- * modifying PW_DEF, GR_DEF, SP_DEF strings (uppercase
- * makes a field mandatory).
+ * delimiters ":") or we will complain with a error message.
+ * b) leading and trailing whitespace in fields is stripped.
+ * c) some fields are not allowed to be empty (e.g. username, uid/gid),
+ * and in this case NULL is returned and errno is set to EINVAL.
+ * This behaviour could be easily changed by modifying PW_DEF, GR_DEF,
+ * SP_DEF strings (uppercase makes a field mandatory).
* d) the string representing uid/gid must be convertible by strtoXX
- * functions or NULL is returned and errno is set to EINVAL.
- * e) leading or trailing whitespaces in member names and empty members
- * are allowed and handled.
- * 3) the internal function for getgrouplist uses a dynamically allocated
- * buffer and retries with a bigger one in case it is too small;
- * 4) the _r functions use the user supplied buffers that are never reallocated
- * but use mostly the same common code as the other functions.
- * 5) at the moment only the functions really used by busybox code are
+ * functions, or errno is set to EINVAL.
+ * e) leading and trailing whitespace in group member names is stripped.
+ * 3) the internal function for getgrouplist uses dynamically allocated buffer.
+ * 4) at the moment only the functions really used by busybox code are
* implemented, if you need a particular missing function it should be
* easy to write it by using the internal common code.
*/
#include "libbb.h"
-/* S = string not empty, s = string maybe empty, */
-/* I = uid,gid, l = long maybe empty, m = members,*/
-/* r = reserved */
-#define PW_DEF "SsIIsSS"
-#define GR_DEF "SsIm"
-#define SP_DEF "Ssllllllr"
-
-static const uint8_t pw_off[] ALIGN1 = {
- offsetof(struct passwd, pw_name), /* 0 S */
- offsetof(struct passwd, pw_passwd), /* 1 s */
- offsetof(struct passwd, pw_uid), /* 2 I */
- offsetof(struct passwd, pw_gid), /* 3 I */
- offsetof(struct passwd, pw_gecos), /* 4 s */
- offsetof(struct passwd, pw_dir), /* 5 S */
- offsetof(struct passwd, pw_shell) /* 6 S */
-};
-static const uint8_t gr_off[] ALIGN1 = {
- offsetof(struct group, gr_name), /* 0 S */
- offsetof(struct group, gr_passwd), /* 1 s */
- offsetof(struct group, gr_gid), /* 2 I */
- offsetof(struct group, gr_mem) /* 3 m (char **) */
-};
-#if ENABLE_USE_BB_SHADOW
-static const uint8_t sp_off[] ALIGN1 = {
- offsetof(struct spwd, sp_namp), /* 0 S Login name */
- offsetof(struct spwd, sp_pwdp), /* 1 s Encrypted password */
- offsetof(struct spwd, sp_lstchg), /* 2 l */
- offsetof(struct spwd, sp_min), /* 3 l */
- offsetof(struct spwd, sp_max), /* 4 l */
- offsetof(struct spwd, sp_warn), /* 5 l */
- offsetof(struct spwd, sp_inact), /* 6 l */
- offsetof(struct spwd, sp_expire), /* 7 l */
- offsetof(struct spwd, sp_flag) /* 8 r Reserved */
-};
-#endif
-
struct const_passdb {
const char *filename;
- const uint8_t *off;
- const char def[10];
+ char def[7 + 2*ENABLE_USE_BB_SHADOW];
+ uint8_t off[7 + 2*ENABLE_USE_BB_SHADOW];
uint8_t numfields;
uint8_t size_of;
};
struct passdb {
const char *filename;
- const uint8_t *off;
- const char def[10];
+ char def[7 + 2*ENABLE_USE_BB_SHADOW];
+ uint8_t off[7 + 2*ENABLE_USE_BB_SHADOW];
uint8_t numfields;
uint8_t size_of;
FILE *fp;
- void *malloced;
+ char *malloced;
};
+/* Note: for shadow db, def[] will not contain terminating NUL,
+ * but convert_to_struct() logic detects def[] end by "less than SP?",
+ * not by "is it NUL?" condition; and off[0] happens to be zero
+ * for every db anyway, so there _is_ in fact a terminating NUL there.
+ */
-static const struct const_passdb const_pw_db = { _PATH_PASSWD, pw_off, PW_DEF, sizeof(PW_DEF)-1, sizeof(struct passwd) };
-static const struct const_passdb const_gr_db = { _PATH_GROUP , gr_off, GR_DEF, sizeof(GR_DEF)-1, sizeof(struct group) };
+/* S = string not empty, s = string maybe empty,
+ * I = uid,gid, l = long maybe empty, m = members,
+ * r = reserved
+ */
+#define PW_DEF "SsIIsss"
+#define GR_DEF "SsIm"
+#define SP_DEF "Ssllllllr"
+
+static const struct const_passdb const_pw_db = {
+ _PATH_PASSWD, PW_DEF,
+ {
+ offsetof(struct passwd, pw_name), /* 0 S */
+ offsetof(struct passwd, pw_passwd), /* 1 s */
+ offsetof(struct passwd, pw_uid), /* 2 I */
+ offsetof(struct passwd, pw_gid), /* 3 I */
+ offsetof(struct passwd, pw_gecos), /* 4 s */
+ offsetof(struct passwd, pw_dir), /* 5 s */
+ offsetof(struct passwd, pw_shell) /* 6 s */
+ },
+ sizeof(PW_DEF)-1, sizeof(struct passwd)
+};
+static const struct const_passdb const_gr_db = {
+ _PATH_GROUP, GR_DEF,
+ {
+ offsetof(struct group, gr_name), /* 0 S */
+ offsetof(struct group, gr_passwd), /* 1 s */
+ offsetof(struct group, gr_gid), /* 2 I */
+ offsetof(struct group, gr_mem) /* 3 m (char **) */
+ },
+ sizeof(GR_DEF)-1, sizeof(struct group)
+};
#if ENABLE_USE_BB_SHADOW
-static const struct const_passdb const_sp_db = { _PATH_SHADOW, sp_off, SP_DEF, sizeof(SP_DEF)-1, sizeof(struct spwd) };
+static const struct const_passdb const_sp_db = {
+ _PATH_SHADOW, SP_DEF,
+ {
+ offsetof(struct spwd, sp_namp), /* 0 S Login name */
+ offsetof(struct spwd, sp_pwdp), /* 1 s Encrypted password */
+ offsetof(struct spwd, sp_lstchg), /* 2 l */
+ offsetof(struct spwd, sp_min), /* 3 l */
+ offsetof(struct spwd, sp_max), /* 4 l */
+ offsetof(struct spwd, sp_warn), /* 5 l */
+ offsetof(struct spwd, sp_inact), /* 6 l */
+ offsetof(struct spwd, sp_expire), /* 7 l */
+ offsetof(struct spwd, sp_flag) /* 8 r Reserved */
+ },
+ sizeof(SP_DEF)-1, sizeof(struct spwd)
+};
#endif
/* We avoid having big global data. */
struct statics {
- /* It's ok to use one buffer for getpwuid and getpwnam. Manpage says:
+ /* We use same buffer (db[0].malloced) for getpwuid and getpwnam.
+ * Manpage says:
* "The return value may point to a static area, and may be overwritten
* by subsequent calls to getpwent(), getpwnam(), or getpwuid()."
*/
struct passdb db[2 + ENABLE_USE_BB_SHADOW];
char *tokenize_end;
+ unsigned string_size;
};
static struct statics *ptr_to_statics;
#define S (*ptr_to_statics)
#define has_S (ptr_to_statics)
+#if ENABLE_FEATURE_CLEAN_UP
+static void free_static(void)
+{
+ free(S.db[0].malloced);
+ free(S.db[1].malloced);
+# if ENABLE_USE_BB_SHADOW
+ free(S.db[2].malloced);
+# endif
+ free(ptr_to_statics);
+}
+#endif
+
static struct statics *get_S(void)
{
if (!ptr_to_statics) {
memcpy(&S.db[1], &const_gr_db, sizeof(const_gr_db));
#if ENABLE_USE_BB_SHADOW
memcpy(&S.db[2], &const_sp_db, sizeof(const_sp_db));
+#endif
+#if ENABLE_FEATURE_CLEAN_UP
+ atexit(free_static);
#endif
}
return ptr_to_statics;
}
-/**********************************************************************/
-/* Internal functions */
-/**********************************************************************/
+/* Internal functions */
/* Divide the passwd/group/shadow record in fields
- * by substituting the given delimeter
+ * by substituting the given delimiter
* e.g. ':' or ',' with '\0'.
- * Returns the number of fields found.
+ * Returns the number of fields found.
* Strips leading and trailing whitespace in fields.
*/
static int tokenize(char *buffer, int ch)
/* Returns !NULL on success and matching line broken up in fields by '\0' in buf.
* We require the expected number of fields to be found.
*/
-static char *parse_common(FILE *fp, const char *filename,
- int n_fields,
+static char *parse_common(FILE *fp, struct passdb *db,
const char *key, int field_pos)
{
- int count = 0;
char *buf;
while ((buf = xmalloc_fgetline(fp)) != NULL) {
- count++;
/* Skip empty lines, comment lines */
if (buf[0] == '\0' || buf[0] == '#')
goto free_and_next;
- if (tokenize(buf, ':') != n_fields) {
+ if (tokenize(buf, ':') != db->numfields) {
/* number of fields is wrong */
- bb_error_msg("bad record at %s:%u", filename, count);
+ bb_error_msg("%s: bad record", db->filename);
goto free_and_next;
}
-/* Ugly hack: group db requires aqdditional buffer space
- * for members[] array. If there is only one group, we need space
- * for 3 pointers: alignment padding, group name, NULL.
- * +1 for every additional group.
- */
- if (n_fields == sizeof(GR_DEF)-1) { /* if we read group file */
- int resize = 3;
- char *p = buf;
- while (*p)
- if (*p++ == ',')
- resize++;
- resize *= sizeof(char**);
- resize += S.tokenize_end - buf;
- buf = xrealloc(buf, resize);
- }
-
- if (!key) {
+ if (field_pos == -1) {
/* no key specified: sequential read, return a record */
break;
}
free(buf);
}
+ S.string_size = S.tokenize_end - buf;
+/*
+ * Ugly hack: group db requires additional buffer space
+ * for members[] array. If there is only one group, we need space
+ * for 3 pointers: alignment padding, group name, NULL.
+ * +1 for every additional group.
+ */
+ if (buf && db->numfields == sizeof(GR_DEF)-1) { /* if we read group file... */
+ int cnt = 3;
+ char *p = buf;
+ while (p < S.tokenize_end)
+ if (*p++ == ',')
+ cnt++;
+ S.string_size += cnt * sizeof(char*);
+//bb_error_msg("+%d words = %u key:%s buf:'%s'", cnt, S.string_size, key, buf);
+ buf = xrealloc(buf, S.string_size);
+ }
+
return buf;
}
-static char *parse_file(const char *filename,
- int n_fields,
+static char *parse_file(struct passdb *db,
const char *key, int field_pos)
{
char *buf = NULL;
- FILE *fp = fopen_for_read(filename);
+ FILE *fp = fopen_for_read(db->filename);
if (fp) {
- buf = parse_common(fp, filename, n_fields, key, field_pos);
+ buf = parse_common(fp, db, key, field_pos);
fclose(fp);
}
return buf;
}
/* Convert passwd/group/shadow file record in buffer to a struct */
-static void *convert_to_struct(const char *def, const unsigned char *off,
+static void *convert_to_struct(struct passdb *db,
char *buffer, void *result)
{
+ const char *def = db->def;
+ const uint8_t *off = db->off;
+
+ /* For consistency, zero out all fields */
+ memset(result, 0, db->size_of);
+
for (;;) {
void *member = (char*)result + (*off++);
* at the end of malloced buffer!
*/
members = (char **)
- ( ((intptr_t)S.tokenize_end + sizeof(char**))
- & -(intptr_t)sizeof(char**)
+ ( ((intptr_t)S.tokenize_end + sizeof(members[0]))
+ & -(intptr_t)sizeof(members[0])
);
-
((struct group *)result)->gr_mem = members;
while (--i >= 0) {
- *members++ = buffer;
+ if (buffer[0]) {
+ *members++ = buffer;
+ // bb_error_msg("member[]='%s'", buffer);
+ }
buffer += strlen(buffer) + 1;
}
*members = NULL;
/* def "r" does nothing */
def++;
- if (*def == '\0')
+ if ((unsigned char)*def <= (unsigned char)' ')
break;
buffer += strlen(buffer) + 1;
}
return result;
}
-/****** getXXnam/id_r */
-
-static int FAST_FUNC getXXnam_r(const char *name, uintptr_t db_and_field_pos, char *buffer, size_t buflen,
- void *result)
+static int massage_data_for_r_func(struct passdb *db,
+ char *buffer, size_t buflen,
+ void **result,
+ char *buf)
{
- void *struct_buf = *(void**)result;
- char *buf;
- struct passdb *db;
- get_S();
- db = &S.db[db_and_field_pos >> 2];
-
- *(void**)result = NULL;
- buf = parse_file(db->filename, db->numfields, name, db_and_field_pos & 3);
+ void *result_buf = *result;
+ *result = NULL;
if (buf) {
- size_t size = S.tokenize_end - buf;
- if (size > buflen) {
+ if (S.string_size > buflen) {
errno = ERANGE;
} else {
- memcpy(buffer, buf, size);
- *(void**)result = convert_to_struct(db->def, db->off, buffer, struct_buf);
+ memcpy(buffer, buf, S.string_size);
+ *result = convert_to_struct(db, buffer, result_buf);
}
free(buf);
}
return errno;
}
-int FAST_FUNC getpwnam_r(const char *name, struct passwd *struct_buf, char *buffer, size_t buflen,
- struct passwd **result)
+static void* massage_data_for_non_r_func(struct passdb *db, char *buf)
+{
+ if (!buf)
+ return NULL;
+
+ free(db->malloced);
+ /* We enlarge buf and move string data up, freeing space
+ * for struct passwd/group/spwd at the beginning. This way,
+ * entire result of getXXnam is in a single malloced block.
+ * This enables easy creation of xmalloc_getpwnam() API.
+ */
+ db->malloced = buf = xrealloc(buf, db->size_of + S.string_size);
+ memmove(buf + db->size_of, buf, S.string_size);
+ return convert_to_struct(db, buf + db->size_of, buf);
+}
+
+/****** getXXnam/id_r */
+
+static int FAST_FUNC getXXnam_r(const char *name, uintptr_t db_and_field_pos,
+ char *buffer, size_t buflen,
+ void *result)
+{
+ char *buf;
+ struct passdb *db = &get_S()->db[db_and_field_pos >> 2];
+
+ buf = parse_file(db, name, 0 /*db_and_field_pos & 3*/);
+ /* "db_and_field_pos & 3" is commented out since so far we don't implement
+ * getXXXid_r() functions which would use that to pass 2 here */
+
+ return massage_data_for_r_func(db, buffer, buflen, result, buf);
+}
+
+int FAST_FUNC getpwnam_r(const char *name, struct passwd *struct_buf,
+ char *buffer, size_t buflen,
+ struct passwd **result)
{
/* Why the "store buffer address in result" trick?
* This way, getXXnam_r has the same ABI signature as getpwnam_r,
}
#if ENABLE_USE_BB_SHADOW
int FAST_FUNC getspnam_r(const char *name, struct spwd *struct_buf, char *buffer, size_t buflen,
- struct spwd **result)
+ struct spwd **result)
{
*result = struct_buf;
return getXXnam_r(name, (2 << 2) + 0, buffer, buflen, result);
}
#endif
+#ifdef UNUSED
/****** getXXent_r */
-static int FAST_FUNC getXXent_r(void *struct_buf, char *buffer, size_t buflen,
- void *result,
- unsigned db_idx)
+static int FAST_FUNC getXXent_r(uintptr_t db_idx, char *buffer, size_t buflen,
+ void *result)
{
char *buf;
- struct passdb *db;
- get_S();
- db = &S.db[db_idx];
-
- *(void**)result = NULL;
+ struct passdb *db = &get_S()->db[db_idx];
if (!db->fp) {
db->fp = fopen_for_read(db->filename);
close_on_exec_on(fileno(db->fp));
}
- buf = parse_common(db->fp, db->filename, db->numfields, /*no search key:*/ NULL, 0);
- if (buf) {
- size_t size = S.tokenize_end - buf;
- if (size > buflen) {
- errno = ERANGE;
- } else {
- memcpy(buffer, buf, size);
- *(void**)result = convert_to_struct(db->def, db->off, buffer, struct_buf);
- }
- free(buf);
- }
- /* "The reentrant functions return zero on success.
- * In case of error, an error number is returned."
- * NB: not finding the record is also a "success" here:
- */
- return errno;
+ buf = parse_common(db->fp, db, /*no search key:*/ NULL, -1);
+ if (!buf && !errno)
+ errno = ENOENT;
+ return massage_data_for_r_func(db, buffer, buflen, result, buf);
}
-int FAST_FUNC getpwent_r(struct passwd *struct_buf, char *buffer, size_t buflen, struct passwd **result)
+int FAST_FUNC getpwent_r(struct passwd *struct_buf, char *buffer, size_t buflen,
+ struct passwd **result)
{
- return getXXent_r(struct_buf, buffer, buflen, result, 0);
+ *result = struct_buf;
+ return getXXent_r(0, buffer, buflen, result);
}
+#endif
-/****** getXXnam/id */
+/****** getXXent */
-static void* FAST_FUNC getXXnam(const char *name, unsigned db_and_field_pos)
+static void* FAST_FUNC getXXent(uintptr_t db_idx)
{
char *buf;
- void *result;
- struct passdb *db;
- get_S();
- db = &S.db[db_and_field_pos >> 2];
-
- result = NULL;
+ struct passdb *db = &get_S()->db[db_idx];
if (!db->fp) {
db->fp = fopen_for_read(db->filename);
close_on_exec_on(fileno(db->fp));
}
- free(db->malloced);
- db->malloced = NULL;
- buf = parse_common(db->fp, db->filename, db->numfields, name, db_and_field_pos & 3);
- if (buf) {
- db->malloced = xzalloc(db->size_of);
- result = convert_to_struct(db->def, db->off, buf, db->malloced);
- }
- return result;
+ buf = parse_common(db->fp, db, /*no search key:*/ NULL, -1);
+ return massage_data_for_non_r_func(db, buf);
+}
+
+struct passwd* FAST_FUNC getpwent(void)
+{
+ return getXXent(0);
+}
+
+/****** getXXnam/id */
+
+static void* FAST_FUNC getXXnam(const char *name, unsigned db_and_field_pos)
+{
+ char *buf;
+ struct passdb *db = &get_S()->db[db_and_field_pos >> 2];
+
+ buf = parse_file(db, name, db_and_field_pos & 3);
+ return massage_data_for_non_r_func(db, buf);
}
struct passwd* FAST_FUNC getpwnam(const char *name)
gid_t *group_list;
int ngroups;
- get_S();
-
/* We alloc space for 8 gids at a time. */
- group_list = xmalloc(8 * sizeof(group_list[0]));
+ group_list = xzalloc(8 * sizeof(group_list[0]));
group_list[0] = gid;
ngroups = 1;
fp = fopen_for_read(_PATH_GROUP);
if (fp) {
+ struct passdb *db = &get_S()->db[1];
char *buf;
- while ((buf = parse_common(fp, _PATH_GROUP, sizeof(GR_DEF)-1, NULL, 0)) != NULL) {
+ while ((buf = parse_common(fp, db, NULL, -1)) != NULL) {
char **m;
struct group group;
- if (!convert_to_struct(GR_DEF, gr_off, buf, &group))
+ if (!convert_to_struct(db, buf, &group))
goto next;
if (group.gr_gid == gid)
goto next;
continue;
group_list = xrealloc_vector(group_list, /*8=2^3:*/ 3, ngroups);
group_list[ngroups++] = group.gr_gid;
- break;
+ goto next;
}
next:
free(buf);
projects / oweals / busybox.git / blobdiff