root/usr.bin/ssh/misc.h
/* $OpenBSD: misc.h,v 1.116 2026/03/11 09:10:59 dtucker Exp $ */

/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 */

#ifndef _MISC_H
#define _MISC_H

#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <signal.h>

/* special-case port number meaning allow any port */
#define FWD_PERMIT_ANY_PORT     0

/* special-case wildcard meaning allow any host */
#define FWD_PERMIT_ANY_HOST     "*"

/* Data structure for representing a forwarding request. */
struct Forward {
        char     *listen_host;          /* Host (address) to listen on. */
        int       listen_port;          /* Port to forward. */
        char     *listen_path;          /* Path to bind domain socket. */
        char     *connect_host;         /* Host to connect. */
        int       connect_port;         /* Port to connect on connect_host. */
        char     *connect_path;         /* Path to connect domain socket. */
        int       allocated_port;       /* Dynamically allocated listen port */
        int       handle;               /* Handle for dynamic listen ports */
};

int forward_equals(const struct Forward *, const struct Forward *);
int permitopen_port(const char *p);

int daemonized(void);

/* Common server and client forwarding options. */
struct ForwardOptions {
        int      gateway_ports; /* Allow remote connects to forwarded ports. */
        mode_t   streamlocal_bind_mask; /* umask for streamlocal binds */
        int      streamlocal_bind_unlink; /* unlink socket before bind */
};

/* misc.c */

char    *chop(char *);
void     rtrim(char *);
void    skip_space(char **);
const char *strprefix(const char *, const char *, int);
char    *strdelim(char **);
char    *strdelimw(char **);
void     stringlist_append(char ***listp, const char *s);
void     stringlist_free(char **list);
int      set_nonblock(int);
int      unset_nonblock(int);
void     set_nodelay(int);
int      set_reuseaddr(int);
char    *get_rdomain(int);
int      set_rdomain(int, const char *);
int      get_sock_af(int);
void     set_sock_tos(int, int);
int      waitrfd(int, int *, volatile sig_atomic_t *);
int      timeout_connect(int, const struct sockaddr *, socklen_t, int *);
int      a2port(const char *);
int      a2tun(const char *, int *);
char    *put_host_port(const char *, u_short);
char    *hpdelim2(char **, char *);
char    *hpdelim(char **);
char    *cleanhostname(char *);
char    *colon(char *);
int      parse_user_host_path(const char *, char **, char **, char **);
int      parse_user_host_port(const char *, char **, char **, int *);
int      parse_uri(const char *, const char *, char **, char **, int *, char **);
double   convtime_double(const char *);
int      convtime(const char *);
double   convtime_double(const char *);
const char *fmt_timeframe(time_t t);
int      tilde_expand(const char *, uid_t, char **);
char    *tilde_expand_filename(const char *, uid_t);

char    *dollar_expand(int *, const char *string, ...);
char    *percent_expand(const char *, ...) __attribute__((__sentinel__));
char    *percent_dollar_expand(const char *, ...) __attribute__((__sentinel__));
char    *tohex(const void *, size_t);
void     xextendf(char **s, const char *sep, const char *fmt, ...)
    __attribute__((__format__ (printf, 3, 4))) __attribute__((__nonnull__ (3)));
void     sanitise_stdfd(void);
void     ms_subtract_diff(struct timeval *, int *);
void     ms_to_timespec(struct timespec *, int);
void     monotime_ts(struct timespec *);
void     monotime_tv(struct timeval *);
time_t   monotime(void);
double   monotime_double(void);
void     lowercase(char *s);
int      unix_listener(const char *, int, int);
int      valid_domain(char *, int, const char **);
int      valid_env_name(const char *);
const char *atoi_err(const char *, int *);
int      parse_absolute_time(const char *, uint64_t *);
void     format_absolute_time(uint64_t, char *, size_t);
int      parse_pattern_interval(const char *, char **, int *);
int      path_absolute(const char *);
int      stdfd_devnull(int, int, int);
int      lib_contains_symbol(const char *, const char *);
char    *get_homedir(void);

struct passwd *pwcopy(struct passwd *);
void     pwfree(struct passwd *); /* NB. only use with pwcopy */

const char *ssh_gai_strerror(int);

typedef void privdrop_fn(struct passwd *);
typedef void privrestore_fn(void);
#define SSH_SUBPROCESS_STDOUT_DISCARD   (1)     /* Discard stdout */
#define SSH_SUBPROCESS_STDOUT_CAPTURE   (1<<1)  /* Redirect stdout */
#define SSH_SUBPROCESS_STDERR_DISCARD   (1<<2)  /* Discard stderr */
#define SSH_SUBPROCESS_UNSAFE_PATH      (1<<3)  /* Don't check for safe cmd */
#define SSH_SUBPROCESS_PRESERVE_ENV     (1<<4)  /* Keep parent environment */
pid_t subprocess(const char *, const char *, int, char **, FILE **, u_int,
    struct passwd *, privdrop_fn *, privrestore_fn *);

typedef struct arglist arglist;
struct arglist {
        char    **list;
        u_int   num;
        u_int   nalloc;
};
void     addargs(arglist *, char *, ...)
            __attribute__((format(printf, 2, 3)));
void     replacearg(arglist *, u_int, char *, ...)
            __attribute__((format(printf, 3, 4)));
void     freeargs(arglist *);

int      tun_open(int, int, char **);

/* Common definitions for ssh tunnel device forwarding */
#define SSH_TUNMODE_NO          0x00
#define SSH_TUNMODE_POINTOPOINT 0x01
#define SSH_TUNMODE_ETHERNET    0x02
#define SSH_TUNMODE_DEFAULT     SSH_TUNMODE_POINTOPOINT
#define SSH_TUNMODE_YES         (SSH_TUNMODE_POINTOPOINT|SSH_TUNMODE_ETHERNET)

#define SSH_TUNID_ANY           0x7fffffff
#define SSH_TUNID_ERR           (SSH_TUNID_ANY - 1)
#define SSH_TUNID_MAX           (SSH_TUNID_ANY - 2)

/* Fake port to indicate that host field is really a path. */
#define PORT_STREAMLOCAL        -2

/* Functions to extract or store big-endian words of various sizes */
uint64_t        get_u64(const void *)
    __attribute__((__bounded__( __minbytes__, 1, 8)));
uint32_t        get_u32(const void *)
    __attribute__((__bounded__( __minbytes__, 1, 4)));
uint16_t        get_u16(const void *)
    __attribute__((__bounded__( __minbytes__, 1, 2)));
void            put_u64(void *, uint64_t)
    __attribute__((__bounded__( __minbytes__, 1, 8)));
void            put_u32(void *, uint32_t)
    __attribute__((__bounded__( __minbytes__, 1, 4)));
void            put_u16(void *, uint16_t)
    __attribute__((__bounded__( __minbytes__, 1, 2)));

/* Little-endian store/load, used by umac.c */
uint32_t        get_u32_le(const void *)
    __attribute__((__bounded__(__minbytes__, 1, 4)));
void            put_u32_le(void *, uint32_t)
    __attribute__((__bounded__(__minbytes__, 1, 4)));

struct bwlimit {
        size_t buflen;
        uint64_t rate;          /* desired rate in kbit/s */
        uint64_t thresh;        /* threshold after which we'll check timers */
        uint64_t lamt;          /* amount written in last timer interval */
        struct timeval bwstart, bwend;
};

void bandwidth_limit_init(struct bwlimit *, uint64_t, size_t);
void bandwidth_limit(struct bwlimit *, size_t);

int parse_ipqos(const char *);
const char *iptos2str(int);
void mktemp_proto(char *, size_t);

void     child_set_env(char ***envp, u_int *envsizep, const char *name,
            const char *value);
const char *lookup_env_in_list(const char *env,
            char * const *envs, size_t nenvs);
const char *lookup_setenv_in_list(const char *env,
            char * const *envs, size_t nenvs);

int      argv_split(const char *, int *, char ***, int);
char    *argv_assemble(int, char **argv);
char    *argv_next(int *, char ***);
void     argv_consume(int *);
void     argv_free(char **, int);

int      exited_cleanly(pid_t, const char *, const char *, int);

struct stat;
int      safe_path(const char *, struct stat *, const char *, uid_t,
            char *, size_t);
int      safe_path_fd(int, const char *, struct passwd *,
            char *err, size_t errlen);

/* authorized_key-style options parsing helpers */
int     opt_flag(const char *opt, int allow_negate, const char **optsp);
char    *opt_dequote(const char **sp, const char **errstrp);
int     opt_match(const char **opts, const char *term);

/* readconf/servconf option lists */
void    opt_array_append(const char *file, const int line,
            const char *directive, char ***array, u_int *lp, const char *s);
void    opt_array_append2(const char *file, const int line,
            const char *directive, char ***array, int **iarray, u_int *lp,
            const char *s, int i);
void    opt_array_free2(char **array, int **iarray, u_int l);

struct timespec;
void ptimeout_init(struct timespec *pt);
void ptimeout_deadline_sec(struct timespec *pt, long sec);
void ptimeout_deadline_ms(struct timespec *pt, long ms);
void ptimeout_deadline_monotime_tsp(struct timespec *pt, struct timespec *when);
void ptimeout_deadline_monotime(struct timespec *pt, time_t when);
int ptimeout_get_ms(struct timespec *pt);
struct timespec *ptimeout_get_tsp(struct timespec *pt);
int ptimeout_isset(struct timespec *pt);

/* misc-agent.c */
char    *agent_hostname_hash(void);
int      agent_listener(const char *, const char *, int *, char **);
void     agent_cleanup_stale(const char *, int);

/* readpass.c */

#define RP_ECHO                 0x0001
#define RP_ALLOW_STDIN          0x0002
#define RP_ALLOW_EOF            0x0004
#define RP_USE_ASKPASS          0x0008

struct notifier_ctx;

char    *read_passphrase(const char *, int);
int      ask_permission(const char *, ...) __attribute__((format(printf, 1, 2)));
struct notifier_ctx *notify_start(int, const char *, ...)
        __attribute__((format(printf, 2, 3)));
void    notify_complete(struct notifier_ctx *, const char *, ...)
        __attribute__((format(printf, 2, 3)));

#define MINIMUM(a, b)   (((a) < (b)) ? (a) : (b))
#define MAXIMUM(a, b)   (((a) > (b)) ? (a) : (b))
#define ROUNDUP(x, y)   ((((x)+((y)-1))/(y))*(y))

typedef void (*sshsig_t)(int);
sshsig_t ssh_signal(int, sshsig_t);
int signal_is_crash(int);

/* On OpenBSD time_t is int64_t which is long long. */
#define SSH_TIME_T_MAX LLONG_MAX

#define FD_CLOSEONEXEC(x) do { \
        if (fcntl(x, F_SETFD, FD_CLOEXEC) == -1) \
                fatal_f("fcntl(%d, F_SETFD, FD_CLOEXEC): %s", x, \
                    strerror(errno)); \
} while (0)


#endif /* _MISC_H */