1 /*
2  *  log.c
3  *
4  *  Copyright (c) 2006-2018 Pacman Development Team <pacman-dev@archlinux.org>
5  *  Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.org>
6  *
7  *  This program is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License as published by
9  *  the Free Software Foundation; either version 2 of the License, or
10  *  (at your option) any later version.
11  *
12  *  This program is distributed in the hope that it will be useful,
13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *  GNU General Public License for more details.
16  *
17  *  You should have received a copy of the GNU General Public License
18  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include <stdio.h>
22 #include <stdarg.h>
23 #include <errno.h>
24 #include <syslog.h>
25 
26 /* libalpm */
27 #include "log.h"
28 #include "handle.h"
29 #include "util.h"
30 #include "alpm.h"
31 
32 /** \addtogroup alpm_log Logging Functions
33  * @brief Functions to log using libalpm
34  * @{
35  */
36 
_alpm_log_leader(FILE * f,const char * prefix)37 static int _alpm_log_leader(FILE *f, const char *prefix)
38 {
39 	time_t t = time(NULL);
40 	struct tm *tm = localtime(&t);
41 
42 	/* Use ISO-8601 date format */
43 	return fprintf(f, "[%04d-%02d-%02d %02d:%02d] [%s] ",
44 			tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
45 			tm->tm_hour, tm->tm_min, prefix);
46 }
47 
48 /** A printf-like function for logging.
49  * @param handle the context handle
50  * @param prefix caller-specific prefix for the log
51  * @param fmt output format
52  * @return 0 on success, -1 on error (pm_errno is set accordingly)
53  */
alpm_logaction(alpm_handle_t * handle,const char * prefix,const char * fmt,...)54 int SYMEXPORT alpm_logaction(alpm_handle_t *handle, const char *prefix,
55 		const char *fmt, ...)
56 {
57 	int ret = 0;
58 	va_list args;
59 
60 	ASSERT(handle != NULL, return -1);
61 
62 	if(!(prefix && *prefix)) {
63 		prefix = "UNKNOWN";
64 	}
65 
66 	/* check if the logstream is open already, opening it if needed */
67 	if(handle->logstream == NULL && handle->logfile != NULL) {
68 		int fd;
69 		do {
70 			fd = open(handle->logfile, O_WRONLY | O_APPEND | O_CREAT | O_CLOEXEC,
71 					0644);
72 		} while(fd == -1 && errno == EINTR);
73 		/* if we couldn't open it, we have an issue */
74 		if(fd < 0 || (handle->logstream = fdopen(fd, "a")) == NULL) {
75 			if(errno == EACCES) {
76 				handle->pm_errno = ALPM_ERR_BADPERMS;
77 			} else if(errno == ENOENT) {
78 				handle->pm_errno = ALPM_ERR_NOT_A_DIR;
79 			} else {
80 				handle->pm_errno = ALPM_ERR_SYSTEM;
81 			}
82 			ret = -1;
83 		}
84 	}
85 
86 	va_start(args, fmt);
87 
88 	if(handle->usesyslog) {
89 		/* we can't use a va_list more than once, so we need to copy it
90 		 * so we can use the original when calling vfprintf below. */
91 		va_list args_syslog;
92 		va_copy(args_syslog, args);
93 		vsyslog(LOG_WARNING, fmt, args_syslog);
94 		va_end(args_syslog);
95 	}
96 
97 	if(handle->logstream) {
98 		if(_alpm_log_leader(handle->logstream, prefix) < 0
99 				|| vfprintf(handle->logstream, fmt, args) < 0) {
100 			ret = -1;
101 			handle->pm_errno = ALPM_ERR_SYSTEM;
102 		}
103 		fflush(handle->logstream);
104 	}
105 
106 	va_end(args);
107 	return ret;
108 }
109 
110 /** @} */
111 
_alpm_log(alpm_handle_t * handle,alpm_loglevel_t flag,const char * fmt,...)112 void _alpm_log(alpm_handle_t *handle, alpm_loglevel_t flag, const char *fmt, ...)
113 {
114 	va_list args;
115 
116 	if(handle == NULL || handle->logcb == NULL) {
117 		return;
118 	}
119 
120 	va_start(args, fmt);
121 	handle->logcb(flag, fmt, args);
122 	va_end(args);
123 }
124