[debian/amanda] / common-src / util.h

/*
 * Amanda, The Advanced Maryland Automatic Network Disk Archiver
 * Copyright (c) 1999 University of Maryland at College Park
 * All Rights Reserved.
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of U.M. not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  U.M. makes no representations about the
 * suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * U.M. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL U.M.
 * BE LIABLE FOR ANY SPECIAL, 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.
 *
 * Authors: the Amanda Development Team.  Its members are listed in a
 * file named AUTHORS, in the root directory of this distribution.
 */
/*
 * $Id: util.h,v 1.17 2006/07/26 15:17:36 martinea Exp $
 */
#ifndef UTIL_H
#define UTIL_H

#include "amanda.h"
#include "sl.h"

#include <glib.h>
#include <glib-object.h>
#include <regex.h>

#include "glib-util.h"

#define BIGINT  INT_MAX

#define BSTRNCMP(a,b)  strncmp(a, b, strlen(b))

/* internal types and variables */

/* Function to get the GQuark for errors,
 * with error codes specified by AmUtilError
 *
 * @return The GQuark that's used for errors
 */
GQuark am_util_error_quark(void);

/* Error codes that may be returned by these functions */
typedef enum {
    AM_UTIL_ERROR_HEXDECODEINVAL,
} AmUtilError;


int     connect_portrange(sockaddr_union *, in_port_t, in_port_t, char *,
                          sockaddr_union *, int);
int     bind_portrange(int, sockaddr_union *, in_port_t, in_port_t,
                       char *);

/* just like an accept() call, but periodically calling PROLONG(PROLONG_DATA) and
 * returning -1 with errno set to 0 if PROLONG returns false.  Note that the socket
 * need not be configured as non-blocking.
 *
 * Other arguments are just like for accept(2).
 */
int     interruptible_accept(int sock, struct sockaddr *addr, socklen_t *addrlen,
            gboolean (*prolong)(gpointer data), gpointer prolong_data);

ssize_t full_writev(int, struct iovec *, int);

char *  construct_datestamp(time_t *t);
char *  construct_timestamp(time_t *t);

/* quote_string only adds "" if they're required; quote_string_always
 * always adds "" around the string */
#define quote_string(str) quote_string_maybe((str), 0)
#define quote_string_always(str) quote_string_maybe((str), 1)
#define len_quote_string(str) len_quote_string_maybe((str), 0);

/*@only@*//*@null@*/char *quote_string_maybe(const char *str, gboolean always);
/*@only@*//*@null@*/char *unquote_string(const char *str);
/*@only@*//*@null@*/int   len_quote_string_maybe(const char *str, gboolean always);

/* Split a string into space-delimited words, obeying quoting as created by
 * quote_string.  To keep compatibility with the old split(), this has the
 * characteristic that multiple consecutive spaces are not collapsed into
 * a single space: "x  y" parses as [ "x", "", "y", NULL ].  The strings are
 * unquoted before they are returned, unlike split().  An empty string is
 * split into [ "", NULL ].
 *
 * Returns a NULL-terminated array of strings, which should be freed with
 * g_strfreev.
 */
gchar ** split_quoted_strings(const gchar *string);

/* Like strtok_r, but consider a quoted string to be a single token.  Caller
 * must begin parsing with strtok_r first, then pass the saveptr to this function.
 *
 * Returns NULL on unparseable strings (e.g., unterminated quotes, bad escapes)
 */
char *          strquotedstr(char **saveptr);

char *  sanitize_string(const char *str);

/* Encode a string using URI-style hexadecimal encoding.
 * Non-alphanumeric characters will be replaced with "%xx"
 * where "xx" is the two-digit hexadecimal representation of the character.
 *
 * @param str The string to encode
 *
 * @return The encoded string. An empty string will be returned for NULL.
 */
char * hexencode_string(const char *str);

/* Decode a string using URI-style hexadecimal encoding.
 *
 * @param str The string to decode
 * @param err return location for a GError
 *
 * @return The decoded string. An empty string will be returned for NULL
 * or if an error occurs.
 */
char * hexdecode_string(const char *str, GError **err);

int     copy_file(char *dst, char *src, char **errmsg);

/* These two functions handle "braced alternates", which is a syntax borrowed,
 * partially, from shells.  See perl/Amanda/Util.pod for a full description of
 * the syntax they support.
 */
GPtrArray * expand_braced_alternates(char * source);
char * collapse_braced_alternates(GPtrArray *source);

/*
 *   validate_email return 0 if the following characters are present
 *   * ( ) < > [ ] , ; : ! $ \ / "
 *   else returns 1
 */
int validate_mailto(const char *mailto);

/* This function is a portable reimplementation of readdir(). It
 * returns a newly-allocated string, that should be freed with
 * free(). Returns NULL on error or end of directory.
 * It is reentrant, with the following exceptions:
 * - This function cannot be run at the same time as readdir() or
 *   readdir64().
 * - This function cannot be run simultaneously on the same directory
 *   handle. */
char * portable_readdir(DIR*);

typedef gboolean (*SearchDirectoryFunctor)(const char * filename,
                                           gpointer user_data);
/* This function will search the given directory handle for files
   matching the given POSIX extended regular expression.
   For each matching file, the functor will be called with the given
   user data. Stops when the functor returns FALSE, or all files have
   been searched. Returns the number of matching files. */
int search_directory(DIR * handle, const char * regex,
                     SearchDirectoryFunctor functor, gpointer user_data);

/* This function extracts a substring match from a regular expression
   match result, and copies it into a newly allocated string. Example
   usage to get the first matched substring:
   substring = find_regmatch(whole_string, pmatch[1])
   Note that pmatch[0] yields the entire matching portion of the string. */
char* find_regex_substring(const char* base_string, const regmatch_t match);

void free_new_argv(int new_argc, char **new_argv);

/* Like strcmp(a, b), except that NULL strings are sorted before non-NULL
 * strings, instead of segfaulting. */
int compare_possibly_null_strings(const char * a, const char * b);

/* Given a hostname, call getaddrinfo to resolve it.  Optionally get the
 * entire set of results (if res is not NULL) and the canonical name of
 * the host (if canonname is not NULL).  The canonical name might
 * expand e.g., www.domain.com to server3.webfarm.hosting.com.
 *
 * If not NULL, the caller is responsible for freeing res with freeaddrinfo().
 * Similarly, the caller is responsible for freeing canonname if it is
 * not NULL.
 *
 * @param hostname: the hostname to start with
 * @param socktype: the socket type (SOCK_DGRAM or SOCK_STREAM)
 * @param res: (result) if not NULL, the results from getaddrinfo()
 * @param canonname: (result) if not NULL, the newly-allocated canonical name of the host
 * @returns: 0 on success, otherwise a getaddrinfo result (for use with gai_strerror)
 */
int resolve_hostname(const char *hostname, int socktype,
                     struct addrinfo **res, char **canonname);

/* Interpret a status (as returned from wait() and friends)
 * into a human-readable sentence.
 *
 * Caller is responsible for freeing the resulting string.
 * The resulting string has already been translated.
 *
 * The macro definition allows this to work even when amwait_t
 * is 'union wait' (4.3BSD).  The cast is safe because the two
 * argument types are interchangeable.
 *
 * @param subject: subject of the sentence (program name, etc.)
 * @param status: the exit status
 * @returns: newly allocated string describing status
 */
#define str_exit_status(subject, status) \
    _str_exit_status((subject), *(amwait_t *)&(status))
char *_str_exit_status(char *subject, amwait_t status);

/*
 * Userid manipulation
 */

/* Check that the current uid and euid are set to a specific user, 
 * calling error() if not. Does nothing if CHECK_USERID is not 
 * defined.  
 *
 * @param who: one of the RUNNING_AS_* constants, below.
 */
typedef enum {
        /* doesn't matter */
    RUNNING_AS_ANY,

        /* userid is 0 */
    RUNNING_AS_ROOT,

        /* userid belongs to dumpuser (from config) */
    RUNNING_AS_DUMPUSER,

        /* prefer that userid belongs to dumpuser, but accept when userid belongs to
         * CLIENT_LOGIN with a debug-log message (needed because amandad always runs
         * as CLIENT_LOGIN, even on server) */
    RUNNING_AS_DUMPUSER_PREFERRED,

        /* userid belongs to CLIENT_LOGIN (from --with-user) */
    RUNNING_AS_CLIENT_LOGIN,

    RUNNING_AS_USER_MASK = (1 << 8) - 1,
        /* '|' this on to only check the uid, not the euid; use this for programs
         * that will call become_root() */
    RUNNING_AS_UID_ONLY = 1 << 8
} running_as_flags;

void check_running_as(running_as_flags who);

/* Drop and regain root priviledges; used from setuid-root binaries which only
 * need to be root for certain operations. Does nothing if SINGLE_USERID is 
 * defined.
 *
 * @param need_root: if 1, try to assume root priviledges; otherwise, drop
 * priviledges.  If -1, drop them irreversibly.
 * @returns: true if the priviledge change succeeded
 */
int set_root_privs(int need_root);

/* Become root completely, by setting the uid to 0.  This is used by setuid-root
 * apps which will exec subprocesses which will also need root priviledges.  Does
 * nothing if SINGLE_USERID is defined.
 *
 * @returns: true if the priviledge change succeeded
 */
int become_root(void);

/*
 * Process parameters
 */

/* The 'context' of a process gives a general description of how it is
 * used.  This affects log output, among other things.
 */
typedef enum {
    /* default context (logging to stderr, etc. -- not pretty) */
    CONTEXT_DEFAULT = 0,

    /* user-interfacing command-line utility like amadmin */
    CONTEXT_CMDLINE,

    /* daemon like amandad or sendbackup */
    CONTEXT_DAEMON,

    /* a utility used from shell scripts, and thus probably invoked
     * quite often */
    CONTEXT_SCRIPTUTIL,
} pcontext_t;

/* Set the name of the process.  The parameter is copied, and remains
 * the responsibility of the caller on return. This value is used in log
 * messages and other output throughout Amanda.
 *
 * @param pname: the new process name
 */
void set_pname(char *pname);

/* Get the current process name; the result is in a static buffer, and
 * should *not* be free()d by the caller.
 *
 * @returns: process name
 */
char *get_pname(void);

/* Set the type of the process.  The parameter is copied, and remains
 * the responsibility of the caller on return.  This value dictates the
 * directory in which debug logs are stored.
 *
 * @param pname: the new process type
 */
void set_ptype(char *ptype);

/* Get the current process name; the result is in a static buffer, and
 * should *not* be free()d by the caller.
 *
 * @returns: process name
 */
char *get_ptype(void);

/* Set the process's context
 *
 * @param context: the new context
 */
void set_pcontext(pcontext_t context);

/* Get the process's context
 *
 * @returns: the context
 */
pcontext_t get_pcontext(void);

/*
 * Readline support
 *
 * This either includes the system readline header we found in configure,
 * or prototypes some simple stub functions that are used instead.
 */

#ifdef HAVE_LIBREADLINE
#  if defined(HAVE_READLINE_READLINE_H)
#    include <readline/readline.h>
#  elif defined(HAVE_READLINE_H)
#    include <readline.h>
#  else /* !defined(HAVE_READLINE_H) */
extern char *readline ();
#  endif /* !defined(HAVE_READLINE_H) */
   /* char *cmdline = NULL; */
#else /* !defined(HAVE_LIBREADLINE) */
  /* use our own readline */
char * readline(const char *prompt);
#endif /* HAVE_LIBREADLINE */

#ifdef HAVE_READLINE_HISTORY
#  if defined(HAVE_READLINE_HISTORY_H)
#    include <readline/history.h>
#  elif defined(HAVE_HISTORY_H)
#    include <history.h>
#  else /* !defined(HAVE_HISTORY_H) */
extern void add_history ();
extern int write_history ();
extern int read_history ();
#  endif /* defined(HAVE_READLINE_HISTORY_H) */
#else /* !defined(HAVE_READLINE_HISTORY) */
  /* use our own add_history */
void   add_history(const char *line);
#endif /* HAVE_READLINE_HISTORY */

char *base64_decode_alloc_string(char *);

/* Inform the OpenBSD pthread library about the high-numbered file descriptors
 * that an amandad service inherits.  This won't be necessary once the new
 * threading library is availble (OpenBSD 5.0?), but won't hurt anyway.  See the
 * thread "Backup issues with OpenBSD 4.5 machines" from September 2009. */
#ifdef __OpenBSD__
void openbsd_fd_inform(void);
#else
#define openbsd_fd_inform()
#endif

/* Add all properties to an ARGV
 *
 * @param argvchild: Pointer to the ARGV.
 * @param proplist: The property list
 */
void property_add_to_argv(GPtrArray *argv_ptr, GHashTable *proplist);

/* Print the argv_ptr with g_debug()
 *
 * @param argv_ptr: GPtrArray of an array to print.
 */
void debug_executing(GPtrArray *argv_ptr);

/* execute the program and get the first line from stdout ot stderr */
char *get_first_line(GPtrArray *argv_ptr);
#endif  /* UTIL_H */