/src/openvswitch/lib/syslog-direct.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * Copyright (c) 2015 Nicira, Inc. |
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 | | #include "syslog-direct.h" |
17 | | |
18 | | #include <config.h> |
19 | | |
20 | | #include <string.h> |
21 | | #include <unistd.h> |
22 | | |
23 | | #include "compiler.h" |
24 | | #include "openvswitch/dynamic-string.h" |
25 | | #include "socket-util.h" |
26 | | #include "syslog-provider.h" |
27 | | #include "util.h" |
28 | | |
29 | 0 | #define FACILITY_MASK 0x03f8 |
30 | | |
31 | | static void syslog_direct_open(struct syslogger *this, int facility); |
32 | | static void syslog_direct_log(struct syslogger *this, int pri, |
33 | | const char *msg); |
34 | | |
35 | | static struct syslog_class syslog_direct_class = { |
36 | | syslog_direct_open, |
37 | | syslog_direct_log, |
38 | | }; |
39 | | |
40 | | struct syslog_direct { |
41 | | struct syslogger parent; |
42 | | int fd; /* Negative number in error case. Otherwise, socket. */ |
43 | | int facility; |
44 | | }; |
45 | | |
46 | | |
47 | | /* This function creates object that directly interacts with syslog over |
48 | | * UDP or Unix domain socket specified in 'method'. */ |
49 | | struct syslogger * |
50 | | syslog_direct_create(const char *method) |
51 | 0 | { |
52 | 0 | struct syslog_direct *this = xmalloc(sizeof *this); |
53 | |
|
54 | 0 | this->parent.class = &syslog_direct_class; |
55 | 0 | this->parent.prefix = "<%B>"; |
56 | | |
57 | | /* socket is created from here (opposed to syslog_direct_open()) |
58 | | * so that deadlocks would be avoided. The problem is that these |
59 | | * functions that create socket might call VLOG() */ |
60 | 0 | if (!strncmp(method, "udp:", 4)) { |
61 | 0 | inet_open_active(SOCK_DGRAM, &method[4], 514, NULL, &this->fd, 0); |
62 | 0 | } else if (!strncmp(method, "unix:", 5)) { |
63 | 0 | this->fd = make_unix_socket(SOCK_DGRAM, true, NULL, &method[5]); |
64 | 0 | } else { |
65 | 0 | this->fd = -1; |
66 | 0 | } |
67 | |
|
68 | 0 | return &this->parent; |
69 | 0 | } |
70 | | |
71 | | static void |
72 | | syslog_direct_open(struct syslogger *this, int facility) |
73 | 0 | { |
74 | 0 | struct syslog_direct *this_ = (struct syslog_direct*) this; |
75 | |
|
76 | 0 | this_->facility = facility; |
77 | 0 | } |
78 | | |
79 | | static void |
80 | | syslog_direct_log(struct syslogger *this, int pri, const char *msg) |
81 | 0 | { |
82 | 0 | static size_t max_len = SIZE_MAX; /* max message size we have discovered |
83 | | * to be able to send() without failing |
84 | | * with EMSGSIZE. */ |
85 | |
|
86 | 0 | struct syslog_direct *this_ = (struct syslog_direct*) this; |
87 | 0 | struct ds ds = DS_EMPTY_INITIALIZER; |
88 | 0 | const char *wire_msg; |
89 | 0 | size_t send_len; |
90 | |
|
91 | 0 | if (this_->fd < 0) { |
92 | | /* Failed to open socket for logging. */ |
93 | 0 | return; |
94 | 0 | } |
95 | | |
96 | 0 | if (!(pri & FACILITY_MASK)) { |
97 | 0 | pri |= this_->facility; |
98 | 0 | } |
99 | 0 | ds_put_format(&ds, "<%u>%s", pri, msg); |
100 | 0 | wire_msg = ds_cstr(&ds); |
101 | 0 | send_len = MIN(strlen(wire_msg), max_len); |
102 | 0 | while (send(this_->fd, wire_msg, send_len, 0) < 0 && errno == EMSGSIZE) { |
103 | | /* If message was too large for send() function then try to discover |
104 | | * max_len supported for this particular socket and retry sending a |
105 | | * truncated version of the same message. */ |
106 | 0 | send_len -= send_len / 20; |
107 | 0 | max_len = send_len; |
108 | 0 | } |
109 | 0 | ds_destroy(&ds); |
110 | 0 | } |