xref: /openbmc/obmc-console/log-handler.c (revision 46d9ef29)
1 /**
2  * Copyright © 2016 IBM Corporation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <endian.h>
18 #include <err.h>
19 #include <fcntl.h>
20 #include <stdbool.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25 
26 #include <sys/mman.h>
27 
28 #include <linux/types.h>
29 
30 #include "console-server.h"
31 
32 struct log_handler {
33 	struct handler handler;
34 	struct console *console;
35 	struct ringbuffer_consumer *rbc;
36 	int fd;
37 	size_t size;
38 	size_t maxsize;
39 	size_t pagesize;
40 	char *log_filename;
41 	char *rotate_filename;
42 };
43 
44 static const char *default_filename = LOCALSTATEDIR "/log/obmc-console.log";
45 static const size_t default_logsize = 16ul * 1024ul;
46 
to_log_handler(struct handler * handler)47 static struct log_handler *to_log_handler(struct handler *handler)
48 {
49 	return container_of(handler, struct log_handler, handler);
50 }
51 
log_trim(struct log_handler * lh)52 static int log_trim(struct log_handler *lh)
53 {
54 	int rc;
55 
56 	/* Move the log buffer file to the rotate file */
57 	close(lh->fd);
58 	rc = rename(lh->log_filename, lh->rotate_filename);
59 	if (rc) {
60 		warn("Failed to rename %s to %s", lh->log_filename,
61 		     lh->rotate_filename);
62 		/* don't return, as we need to re-open the logfile */
63 	}
64 
65 	lh->fd = open(lh->log_filename, O_WRONLY | O_CREAT | O_TRUNC, 0644);
66 	if (lh->fd < 0) {
67 		warn("Can't open log buffer file %s", lh->log_filename);
68 		return -1;
69 	}
70 
71 	lh->size = 0;
72 
73 	return 0;
74 }
75 
log_data(struct log_handler * lh,uint8_t * buf,size_t len)76 static int log_data(struct log_handler *lh, uint8_t *buf, size_t len)
77 {
78 	int rc;
79 
80 	if (len > lh->maxsize) {
81 		buf += len - lh->maxsize;
82 		len = lh->maxsize;
83 	}
84 
85 	if (lh->size + len > lh->maxsize) {
86 		rc = log_trim(lh);
87 		if (rc) {
88 			return rc;
89 		}
90 	}
91 
92 	rc = write_buf_to_fd(lh->fd, buf, len);
93 	if (rc) {
94 		return rc;
95 	}
96 
97 	lh->size += len;
98 
99 	return 0;
100 }
101 
log_ringbuffer_poll(void * arg,size_t force_len)102 static enum ringbuffer_poll_ret log_ringbuffer_poll(void *arg, size_t force_len
103 						    __attribute__((unused)))
104 {
105 	struct log_handler *lh = arg;
106 	uint8_t *buf;
107 	size_t len;
108 	int rc;
109 
110 	/* we log synchronously, so just dequeue everything we can, and
111 	 * commit straight away. */
112 	for (;;) {
113 		len = ringbuffer_dequeue_peek(lh->rbc, 0, &buf);
114 		if (!len) {
115 			break;
116 		}
117 
118 		rc = log_data(lh, buf, len);
119 		if (rc) {
120 			return RINGBUFFER_POLL_REMOVE;
121 		}
122 
123 		ringbuffer_dequeue_commit(lh->rbc, len);
124 	}
125 
126 	return RINGBUFFER_POLL_OK;
127 }
128 
log_create(struct log_handler * lh)129 static int log_create(struct log_handler *lh)
130 {
131 	off_t pos;
132 
133 	lh->fd = open(lh->log_filename, O_WRONLY | O_CREAT | O_APPEND, 0644);
134 	if (lh->fd < 0) {
135 		warn("Can't open log buffer file %s", lh->log_filename);
136 		return -1;
137 	}
138 	pos = lseek(lh->fd, 0, SEEK_CUR);
139 	if (pos < 0) {
140 		warn("Can't query log position for file %s", lh->log_filename);
141 		close(lh->fd);
142 		return -1;
143 	}
144 	lh->size = pos;
145 	if ((size_t)pos >= lh->maxsize) {
146 		return log_trim(lh);
147 	}
148 
149 	return 0;
150 }
151 
log_init(struct handler * handler,struct console * console,struct config * config)152 static int log_init(struct handler *handler, struct console *console,
153 		    struct config *config)
154 {
155 	struct log_handler *lh = to_log_handler(handler);
156 	const char *filename;
157 	const char *logsize_str;
158 	size_t logsize = default_logsize;
159 	int rc;
160 
161 	lh->console = console;
162 	lh->pagesize = 4096;
163 	lh->size = 0;
164 	lh->log_filename = NULL;
165 	lh->rotate_filename = NULL;
166 
167 	logsize_str = config_get_value(config, "logsize");
168 	rc = config_parse_bytesize(logsize_str, &logsize);
169 	if (logsize_str != NULL && rc) {
170 		logsize = default_logsize;
171 		warn("Invalid logsize. Default to %ukB",
172 		     (unsigned int)(logsize >> 10));
173 	}
174 	lh->maxsize = logsize <= lh->pagesize ? lh->pagesize + 1 : logsize;
175 
176 	filename = config_get_value(config, "logfile");
177 	if (!filename) {
178 		filename = default_filename;
179 	}
180 
181 	lh->log_filename = strdup(filename);
182 
183 	rc = asprintf(&lh->rotate_filename, "%s.1", filename);
184 	if (rc < 0) {
185 		warn("Failed to construct rotate filename");
186 		return -1;
187 	}
188 
189 	rc = log_create(lh);
190 	if (rc < 0) {
191 		return -1;
192 	}
193 	lh->rbc = console_ringbuffer_consumer_register(console,
194 						       log_ringbuffer_poll, lh);
195 
196 	return 0;
197 }
198 
log_fini(struct handler * handler)199 static void log_fini(struct handler *handler)
200 {
201 	struct log_handler *lh = to_log_handler(handler);
202 	ringbuffer_consumer_unregister(lh->rbc);
203 	close(lh->fd);
204 	free(lh->log_filename);
205 	free(lh->rotate_filename);
206 }
207 
208 static struct log_handler log_handler = {
209 	.handler = {
210 		.name		= "log",
211 		.init		= log_init,
212 		.fini		= log_fini,
213 	},
214 };
215 
216 console_handler_register(&log_handler.handler);
217