1 /*        $NetBSD: log.h,v 1.19 2025/04/09 15:49:32 christos Exp $    */
2 /* $OpenBSD: log.h,v 1.35 2024/12/07 10:05:37 djm Exp $ */
3 
4 /*
5  * Author: Tatu Ylonen <ylo@cs.hut.fi>
6  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
7  *                    All rights reserved
8  *
9  * As far as I am concerned, the code I have written for this software
10  * can be used freely for any purpose.  Any derived versions of this
11  * software must be clearly marked as such, and if the derived work is
12  * incompatible with the protocol description in the RFC file, it must be
13  * called by a name other than "ssh" or "Secure Shell".
14  */
15 
16 #ifndef SSH_LOG_H
17 #define SSH_LOG_H
18 
19 #include <stdarg.h> /* va_list */
20 #include "ssherr.h" /* ssh_err() */
21 
22 /* Supported syslog facilities and levels. */
23 typedef enum {
24           SYSLOG_FACILITY_DAEMON,
25           SYSLOG_FACILITY_USER,
26           SYSLOG_FACILITY_AUTH,
27           SYSLOG_FACILITY_LOCAL0,
28           SYSLOG_FACILITY_LOCAL1,
29           SYSLOG_FACILITY_LOCAL2,
30           SYSLOG_FACILITY_LOCAL3,
31           SYSLOG_FACILITY_LOCAL4,
32           SYSLOG_FACILITY_LOCAL5,
33           SYSLOG_FACILITY_LOCAL6,
34           SYSLOG_FACILITY_LOCAL7,
35           SYSLOG_FACILITY_NOT_SET = -1
36 }       SyslogFacility;
37 
38 typedef enum {
39           SYSLOG_LEVEL_QUIET,
40           SYSLOG_LEVEL_FATAL,
41           SYSLOG_LEVEL_ERROR,
42           SYSLOG_LEVEL_INFO,
43           SYSLOG_LEVEL_VERBOSE,
44           SYSLOG_LEVEL_DEBUG1,
45           SYSLOG_LEVEL_DEBUG2,
46           SYSLOG_LEVEL_DEBUG3,
47           SYSLOG_LEVEL_NOT_SET = -1
48 }       LogLevel;
49 
50 typedef void (log_handler_fn)(LogLevel, int, const char *, void *);
51 
52 void     log_init(const char *, LogLevel, SyslogFacility, int);
53 LogLevel log_level_get(void);
54 int      log_change_level(LogLevel);
55 int      log_is_on_stderr(void);
56 void     log_redirect_stderr_to(const char *);
57 void       log_verbose_add(const char *);
58 void       log_verbose_reset(void);
59 
60 SyslogFacility      log_facility_number(char *);
61 const char *        log_facility_name(SyslogFacility);
62 LogLevel  log_level_number(char *);
63 const char *        log_level_name(LogLevel);
64 
65 void       set_log_handler(log_handler_fn *, void *);
66 void       cleanup_exit(int) __attribute__((noreturn));
67 
68 void       sshlog(const char *, const char *, int, int,
69     LogLevel, const char *, const char *, ...)
70     __attribute__((format(printf, 7, 8)));
71 void       sshlogv(const char *, const char *, int, int,
72     LogLevel, const char *, const char *, va_list);
73 void       sshlogdie(const char *, const char *, int, int,
74     LogLevel, const char *, const char *, ...) __attribute__((noreturn))
75     __attribute__((format(printf, 7, 8)));
76 void       sshfatal(const char *, const char *, int, int,
77     LogLevel, const char *, const char *, ...) __attribute__((noreturn))
78     __attribute__((format(printf, 7, 8)));
79 void       sshlogdirect(LogLevel, int, const char *, ...)
80     __attribute__((format(printf, 3, 4)));
81 
82 struct log_ratelimit_ctx {
83           /* configuration */
84           u_int threshold;    /* events per second */
85           u_int max_accum;    /* max events to accumulate */
86           u_int hysteresis;   /* seconds */
87           u_int log_every;    /* seconds */
88 
89           /* state */
90           time_t last_event;
91           u_int accumulated_events; /* used for threshold comparisons */
92 
93           /* state while actively rate-limiting */
94           int ratelimit_active;
95           time_t ratelimit_start;
96           time_t last_log;
97           time_t hysteresis_start;
98           u_int ratelimited_events;
99 };
100 
101 void log_ratelimit_init(struct log_ratelimit_ctx *rl, u_int threshold,
102     u_int max_accum, u_int hysteresis, u_int log_every);
103 int log_ratelimit(struct log_ratelimit_ctx *rl, time_t now, int *active,
104     u_int *events_dropped);
105 
106 #define do_log2(level, ...)   sshlog(__FILE__, __func__, __LINE__, 0, level, NULL, __VA_ARGS__)
107 #define debug3(...)           sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_DEBUG3, NULL, __VA_ARGS__)
108 #define debug2(...)           sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_DEBUG2, NULL, __VA_ARGS__)
109 #define debug(...)            sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_DEBUG1, NULL, __VA_ARGS__)
110 #define verbose(...)                    sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_VERBOSE, NULL, __VA_ARGS__)
111 #define logit(...)            sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_INFO, NULL, __VA_ARGS__)
112 #define error(...)            sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_ERROR, NULL, __VA_ARGS__)
113 #define fatal(...)            sshfatal(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_FATAL, NULL, __VA_ARGS__)
114 #define logdie(...)           sshlogdie(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_ERROR, NULL, __VA_ARGS__)
115 
116 /* Variants that prepend the caller's function */
117 #define do_log2_f(level, ...) sshlog(__FILE__, __func__, __LINE__, 1, level, NULL, __VA_ARGS__)
118 #define debug3_f(...)                   sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_DEBUG3, NULL, __VA_ARGS__)
119 #define debug2_f(...)                   sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_DEBUG2, NULL, __VA_ARGS__)
120 #define debug_f(...)                    sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_DEBUG1, NULL, __VA_ARGS__)
121 #define verbose_f(...)                  sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_VERBOSE, NULL, __VA_ARGS__)
122 #define logit_f(...)                    sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_INFO, NULL, __VA_ARGS__)
123 #define error_f(...)                    sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_ERROR, NULL, __VA_ARGS__)
124 #define fatal_f(...)                    sshfatal(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_FATAL, NULL, __VA_ARGS__)
125 #define logdie_f(...)                   sshlogdie(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_ERROR, NULL, __VA_ARGS__)
126 
127 /* Variants that appends a ssh_err message */
128 #define do_log2_r(r, level, ...) sshlog(__FILE__, __func__, __LINE__, 0, level, ssh_err(r), __VA_ARGS__)
129 #define debug3_r(r, ...)      sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_DEBUG3, ssh_err(r), __VA_ARGS__)
130 #define debug2_r(r, ...)      sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_DEBUG2, ssh_err(r), __VA_ARGS__)
131 #define debug_r(r, ...)                 sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_DEBUG1, ssh_err(r), __VA_ARGS__)
132 #define verbose_r(r, ...)     sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_VERBOSE, ssh_err(r), __VA_ARGS__)
133 #define logit_r(r, ...)                 sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_INFO, ssh_err(r), __VA_ARGS__)
134 #define error_r(r, ...)                 sshlog(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_ERROR, ssh_err(r), __VA_ARGS__)
135 #define fatal_r(r, ...)                 sshfatal(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_FATAL, ssh_err(r), __VA_ARGS__)
136 #define logdie_r(r, ...)      sshlogdie(__FILE__, __func__, __LINE__, 0, SYSLOG_LEVEL_ERROR, ssh_err(r), __VA_ARGS__)
137 #define do_log2_fr(r, level, ...) sshlog(__FILE__, __func__, __LINE__, 1, level, ssh_err(r), __VA_ARGS__)
138 #define debug3_fr(r, ...)     sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_DEBUG3, ssh_err(r), __VA_ARGS__)
139 #define debug2_fr(r, ...)     sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_DEBUG2, ssh_err(r), __VA_ARGS__)
140 #define debug_fr(r, ...)      sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_DEBUG1, ssh_err(r), __VA_ARGS__)
141 #define verbose_fr(r, ...)    sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_VERBOSE, ssh_err(r), __VA_ARGS__)
142 #define logit_fr(r, ...)      sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_INFO, ssh_err(r), __VA_ARGS__)
143 #define error_fr(r, ...)      sshlog(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_ERROR, ssh_err(r), __VA_ARGS__)
144 #define fatal_fr(r, ...)      sshfatal(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_FATAL, ssh_err(r), __VA_ARGS__)
145 #define logdie_fr(r, ...)     sshlogdie(__FILE__, __func__, __LINE__, 1, SYSLOG_LEVEL_ERROR, ssh_err(r), __VA_ARGS__)
146 
147 #endif
148