xref: /openbsd/usr.bin/ssh/misc.h (revision c2ff6de8)
1 /* $OpenBSD: misc.h,v 1.110 2024/09/25 01:24:04 djm Exp $ */
2 
3 /*
4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6  *                    All rights reserved
7  *
8  * As far as I am concerned, the code I have written for this software
9  * can be used freely for any purpose.  Any derived versions of this
10  * software must be clearly marked as such, and if the derived work is
11  * incompatible with the protocol description in the RFC file, it must be
12  * called by a name other than "ssh" or "Secure Shell".
13  */
14 
15 #ifndef _MISC_H
16 #define _MISC_H
17 
18 #include <sys/time.h>
19 #include <sys/types.h>
20 #include <sys/socket.h>
21 #include <stdio.h>
22 #include <signal.h>
23 
24 /* special-case port number meaning allow any port */
25 #define FWD_PERMIT_ANY_PORT	0
26 
27 /* special-case wildcard meaning allow any host */
28 #define FWD_PERMIT_ANY_HOST	"*"
29 
30 /* Data structure for representing a forwarding request. */
31 struct Forward {
32 	char	 *listen_host;		/* Host (address) to listen on. */
33 	int	  listen_port;		/* Port to forward. */
34 	char	 *listen_path;		/* Path to bind domain socket. */
35 	char	 *connect_host;		/* Host to connect. */
36 	int	  connect_port;		/* Port to connect on connect_host. */
37 	char	 *connect_path;		/* Path to connect domain socket. */
38 	int	  allocated_port;	/* Dynamically allocated listen port */
39 	int	  handle;		/* Handle for dynamic listen ports */
40 };
41 
42 int forward_equals(const struct Forward *, const struct Forward *);
43 int permitopen_port(const char *p);
44 
45 int daemonized(void);
46 
47 /* Common server and client forwarding options. */
48 struct ForwardOptions {
49 	int	 gateway_ports; /* Allow remote connects to forwarded ports. */
50 	mode_t	 streamlocal_bind_mask; /* umask for streamlocal binds */
51 	int	 streamlocal_bind_unlink; /* unlink socket before bind */
52 };
53 
54 /* misc.c */
55 
56 char	*chop(char *);
57 void	 rtrim(char *);
58 void	skip_space(char **);
59 const char *strprefix(const char *, const char *, int);
60 char	*strdelim(char **);
61 char	*strdelimw(char **);
62 int	 set_nonblock(int);
63 int	 unset_nonblock(int);
64 void	 set_nodelay(int);
65 int	 set_reuseaddr(int);
66 char	*get_rdomain(int);
67 int	 set_rdomain(int, const char *);
68 int	 get_sock_af(int);
69 void	 set_sock_tos(int, int);
70 int	 waitrfd(int, int *, volatile sig_atomic_t *);
71 int	 timeout_connect(int, const struct sockaddr *, socklen_t, int *);
72 int	 a2port(const char *);
73 int	 a2tun(const char *, int *);
74 char	*put_host_port(const char *, u_short);
75 char	*hpdelim2(char **, char *);
76 char	*hpdelim(char **);
77 char	*cleanhostname(char *);
78 char	*colon(char *);
79 int	 parse_user_host_path(const char *, char **, char **, char **);
80 int	 parse_user_host_port(const char *, char **, char **, int *);
81 int	 parse_uri(const char *, const char *, char **, char **, int *, char **);
82 int	 convtime(const char *);
83 const char *fmt_timeframe(time_t t);
84 int	 tilde_expand(const char *, uid_t, char **);
85 char	*tilde_expand_filename(const char *, uid_t);
86 
87 char	*dollar_expand(int *, const char *string, ...);
88 char	*percent_expand(const char *, ...) __attribute__((__sentinel__));
89 char	*percent_dollar_expand(const char *, ...) __attribute__((__sentinel__));
90 char	*tohex(const void *, size_t);
91 void	 xextendf(char **s, const char *sep, const char *fmt, ...)
92     __attribute__((__format__ (printf, 3, 4))) __attribute__((__nonnull__ (3)));
93 void	 sanitise_stdfd(void);
94 void	 ms_subtract_diff(struct timeval *, int *);
95 void	 ms_to_timespec(struct timespec *, int);
96 void	 monotime_ts(struct timespec *);
97 void	 monotime_tv(struct timeval *);
98 time_t	 monotime(void);
99 double	 monotime_double(void);
100 void	 lowercase(char *s);
101 int	 unix_listener(const char *, int, int);
102 int	 valid_domain(char *, int, const char **);
103 int	 valid_env_name(const char *);
104 const char *atoi_err(const char *, int *);
105 int	 parse_absolute_time(const char *, uint64_t *);
106 void	 format_absolute_time(uint64_t, char *, size_t);
107 int	 parse_pattern_interval(const char *, char **, int *);
108 int	 path_absolute(const char *);
109 int	 stdfd_devnull(int, int, int);
110 int	 lib_contains_symbol(const char *, const char *);
111 
112 struct passwd *pwcopy(struct passwd *);
113 const char *ssh_gai_strerror(int);
114 
115 typedef void privdrop_fn(struct passwd *);
116 typedef void privrestore_fn(void);
117 #define	SSH_SUBPROCESS_STDOUT_DISCARD	(1)     /* Discard stdout */
118 #define	SSH_SUBPROCESS_STDOUT_CAPTURE	(1<<1)  /* Redirect stdout */
119 #define	SSH_SUBPROCESS_STDERR_DISCARD	(1<<2)  /* Discard stderr */
120 #define	SSH_SUBPROCESS_UNSAFE_PATH	(1<<3)	/* Don't check for safe cmd */
121 #define	SSH_SUBPROCESS_PRESERVE_ENV	(1<<4)	/* Keep parent environment */
122 pid_t subprocess(const char *, const char *, int, char **, FILE **, u_int,
123     struct passwd *, privdrop_fn *, privrestore_fn *);
124 
125 typedef struct arglist arglist;
126 struct arglist {
127 	char    **list;
128 	u_int   num;
129 	u_int   nalloc;
130 };
131 void	 addargs(arglist *, char *, ...)
132 	    __attribute__((format(printf, 2, 3)));
133 void	 replacearg(arglist *, u_int, char *, ...)
134 	    __attribute__((format(printf, 3, 4)));
135 void	 freeargs(arglist *);
136 
137 int	 tun_open(int, int, char **);
138 
139 /* Common definitions for ssh tunnel device forwarding */
140 #define SSH_TUNMODE_NO		0x00
141 #define SSH_TUNMODE_POINTOPOINT	0x01
142 #define SSH_TUNMODE_ETHERNET	0x02
143 #define SSH_TUNMODE_DEFAULT	SSH_TUNMODE_POINTOPOINT
144 #define SSH_TUNMODE_YES		(SSH_TUNMODE_POINTOPOINT|SSH_TUNMODE_ETHERNET)
145 
146 #define SSH_TUNID_ANY		0x7fffffff
147 #define SSH_TUNID_ERR		(SSH_TUNID_ANY - 1)
148 #define SSH_TUNID_MAX		(SSH_TUNID_ANY - 2)
149 
150 /* Fake port to indicate that host field is really a path. */
151 #define PORT_STREAMLOCAL	-2
152 
153 /* Functions to extract or store big-endian words of various sizes */
154 u_int64_t	get_u64(const void *)
155     __attribute__((__bounded__( __minbytes__, 1, 8)));
156 u_int32_t	get_u32(const void *)
157     __attribute__((__bounded__( __minbytes__, 1, 4)));
158 u_int16_t	get_u16(const void *)
159     __attribute__((__bounded__( __minbytes__, 1, 2)));
160 void		put_u64(void *, u_int64_t)
161     __attribute__((__bounded__( __minbytes__, 1, 8)));
162 void		put_u32(void *, u_int32_t)
163     __attribute__((__bounded__( __minbytes__, 1, 4)));
164 void		put_u16(void *, u_int16_t)
165     __attribute__((__bounded__( __minbytes__, 1, 2)));
166 
167 /* Little-endian store/load, used by umac.c */
168 u_int32_t	get_u32_le(const void *)
169     __attribute__((__bounded__(__minbytes__, 1, 4)));
170 void		put_u32_le(void *, u_int32_t)
171     __attribute__((__bounded__(__minbytes__, 1, 4)));
172 
173 struct bwlimit {
174 	size_t buflen;
175 	u_int64_t rate;		/* desired rate in kbit/s */
176 	u_int64_t thresh;	/* threshold after which we'll check timers */
177 	u_int64_t lamt;		/* amount written in last timer interval */
178 	struct timeval bwstart, bwend;
179 };
180 
181 void bandwidth_limit_init(struct bwlimit *, u_int64_t, size_t);
182 void bandwidth_limit(struct bwlimit *, size_t);
183 
184 int parse_ipqos(const char *);
185 const char *iptos2str(int);
186 void mktemp_proto(char *, size_t);
187 
188 void	 child_set_env(char ***envp, u_int *envsizep, const char *name,
189 	    const char *value);
190 const char *lookup_env_in_list(const char *env,
191 	    char * const *envs, size_t nenvs);
192 const char *lookup_setenv_in_list(const char *env,
193 	    char * const *envs, size_t nenvs);
194 
195 int	 argv_split(const char *, int *, char ***, int);
196 char	*argv_assemble(int, char **argv);
197 char	*argv_next(int *, char ***);
198 void	 argv_consume(int *);
199 void	 argv_free(char **, int);
200 
201 int	 exited_cleanly(pid_t, const char *, const char *, int);
202 
203 struct stat;
204 int	 safe_path(const char *, struct stat *, const char *, uid_t,
205 	    char *, size_t);
206 int	 safe_path_fd(int, const char *, struct passwd *,
207 	    char *err, size_t errlen);
208 
209 /* authorized_key-style options parsing helpers */
210 int	opt_flag(const char *opt, int allow_negate, const char **optsp);
211 char	*opt_dequote(const char **sp, const char **errstrp);
212 int	opt_match(const char **opts, const char *term);
213 
214 /* readconf/servconf option lists */
215 void	opt_array_append(const char *file, const int line,
216 	    const char *directive, char ***array, u_int *lp, const char *s);
217 void	opt_array_append2(const char *file, const int line,
218 	    const char *directive, char ***array, int **iarray, u_int *lp,
219 	    const char *s, int i);
220 void	opt_array_free2(char **array, int **iarray, u_int l);
221 
222 struct timespec;
223 void ptimeout_init(struct timespec *pt);
224 void ptimeout_deadline_sec(struct timespec *pt, long sec);
225 void ptimeout_deadline_ms(struct timespec *pt, long ms);
226 void ptimeout_deadline_monotime_tsp(struct timespec *pt, struct timespec *when);
227 void ptimeout_deadline_monotime(struct timespec *pt, time_t when);
228 int ptimeout_get_ms(struct timespec *pt);
229 struct timespec *ptimeout_get_tsp(struct timespec *pt);
230 int ptimeout_isset(struct timespec *pt);
231 
232 /* readpass.c */
233 
234 #define RP_ECHO			0x0001
235 #define RP_ALLOW_STDIN		0x0002
236 #define RP_ALLOW_EOF		0x0004
237 #define RP_USE_ASKPASS		0x0008
238 
239 struct notifier_ctx;
240 
241 char	*read_passphrase(const char *, int);
242 int	 ask_permission(const char *, ...) __attribute__((format(printf, 1, 2)));
243 struct notifier_ctx *notify_start(int, const char *, ...)
244 	__attribute__((format(printf, 2, 3)));
245 void	notify_complete(struct notifier_ctx *, const char *, ...)
246 	__attribute__((format(printf, 2, 3)));
247 
248 #define MINIMUM(a, b)	(((a) < (b)) ? (a) : (b))
249 #define MAXIMUM(a, b)	(((a) > (b)) ? (a) : (b))
250 #define ROUNDUP(x, y)   ((((x)+((y)-1))/(y))*(y))
251 
252 typedef void (*sshsig_t)(int);
253 sshsig_t ssh_signal(int, sshsig_t);
254 int signal_is_crash(int);
255 
256 /* On OpenBSD time_t is int64_t which is long long. */
257 #define SSH_TIME_T_MAX LLONG_MAX
258 
259 #endif /* _MISC_H */
260