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Commit | Line | Data |
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ee4512ed JH |
1 | #include "cache.h" |
2 | #include "trace2/tr2_dst.h" | |
a4d3a283 | 3 | #include "trace2/tr2_sid.h" |
bce9db6d | 4 | #include "trace2/tr2_sysenv.h" |
ee4512ed | 5 | |
a4d3a283 JS |
6 | /* |
7 | * How many attempts we will make at creating an automatically-named trace file. | |
8 | */ | |
9 | #define MAX_AUTO_ATTEMPTS 10 | |
10 | ||
ee4512ed JH |
11 | static int tr2_dst_want_warning(void) |
12 | { | |
13 | static int tr2env_dst_debug = -1; | |
14 | ||
15 | if (tr2env_dst_debug == -1) { | |
bce9db6d | 16 | const char *env_value = tr2_sysenv_get(TR2_SYSENV_DST_DEBUG); |
ee4512ed JH |
17 | if (!env_value || !*env_value) |
18 | tr2env_dst_debug = 0; | |
19 | else | |
20 | tr2env_dst_debug = atoi(env_value) > 0; | |
21 | } | |
22 | ||
23 | return tr2env_dst_debug; | |
24 | } | |
25 | ||
26 | void tr2_dst_trace_disable(struct tr2_dst *dst) | |
27 | { | |
28 | if (dst->need_close) | |
29 | close(dst->fd); | |
30 | dst->fd = 0; | |
31 | dst->initialized = 1; | |
32 | dst->need_close = 0; | |
33 | } | |
34 | ||
a4d3a283 JS |
35 | static int tr2_dst_try_auto_path(struct tr2_dst *dst, const char *tgt_prefix) |
36 | { | |
37 | int fd; | |
38 | const char *last_slash, *sid = tr2_sid_get(); | |
39 | struct strbuf path = STRBUF_INIT; | |
40 | size_t base_path_len; | |
41 | unsigned attempt_count; | |
42 | ||
43 | last_slash = strrchr(sid, '/'); | |
44 | if (last_slash) | |
45 | sid = last_slash + 1; | |
46 | ||
47 | strbuf_addstr(&path, tgt_prefix); | |
48 | if (!is_dir_sep(path.buf[path.len - 1])) | |
49 | strbuf_addch(&path, '/'); | |
50 | strbuf_addstr(&path, sid); | |
51 | base_path_len = path.len; | |
52 | ||
53 | for (attempt_count = 0; attempt_count < MAX_AUTO_ATTEMPTS; attempt_count++) { | |
54 | if (attempt_count > 0) { | |
55 | strbuf_setlen(&path, base_path_len); | |
56 | strbuf_addf(&path, ".%d", attempt_count); | |
57 | } | |
58 | ||
59 | fd = open(path.buf, O_WRONLY | O_CREAT | O_EXCL, 0666); | |
60 | if (fd != -1) | |
61 | break; | |
62 | } | |
63 | ||
64 | if (fd == -1) { | |
65 | if (tr2_dst_want_warning()) | |
66 | warning("trace2: could not open '%.*s' for '%s' tracing: %s", | |
67 | (int) base_path_len, path.buf, | |
5b2d1c0c JH |
68 | tr2_sysenv_display_name(dst->sysenv_var), |
69 | strerror(errno)); | |
a4d3a283 JS |
70 | |
71 | tr2_dst_trace_disable(dst); | |
72 | strbuf_release(&path); | |
73 | return 0; | |
74 | } | |
75 | ||
76 | strbuf_release(&path); | |
77 | ||
78 | dst->fd = fd; | |
79 | dst->need_close = 1; | |
80 | dst->initialized = 1; | |
81 | ||
82 | return dst->fd; | |
83 | } | |
84 | ||
ee4512ed JH |
85 | static int tr2_dst_try_path(struct tr2_dst *dst, const char *tgt_value) |
86 | { | |
87 | int fd = open(tgt_value, O_WRONLY | O_APPEND | O_CREAT, 0666); | |
88 | if (fd == -1) { | |
89 | if (tr2_dst_want_warning()) | |
90 | warning("trace2: could not open '%s' for '%s' tracing: %s", | |
bce9db6d JH |
91 | tgt_value, |
92 | tr2_sysenv_display_name(dst->sysenv_var), | |
93 | strerror(errno)); | |
ee4512ed JH |
94 | |
95 | tr2_dst_trace_disable(dst); | |
96 | return 0; | |
97 | } | |
98 | ||
99 | dst->fd = fd; | |
100 | dst->need_close = 1; | |
101 | dst->initialized = 1; | |
102 | ||
103 | return dst->fd; | |
104 | } | |
105 | ||
106 | #ifndef NO_UNIX_SOCKETS | |
107 | #define PREFIX_AF_UNIX "af_unix:" | |
108 | #define PREFIX_AF_UNIX_STREAM "af_unix:stream:" | |
109 | #define PREFIX_AF_UNIX_DGRAM "af_unix:dgram:" | |
110 | ||
111 | static int tr2_dst_try_uds_connect(const char *path, int sock_type, int *out_fd) | |
112 | { | |
113 | int fd; | |
114 | struct sockaddr_un sa; | |
115 | ||
116 | fd = socket(AF_UNIX, sock_type, 0); | |
117 | if (fd == -1) | |
118 | return errno; | |
119 | ||
120 | sa.sun_family = AF_UNIX; | |
121 | strlcpy(sa.sun_path, path, sizeof(sa.sun_path)); | |
122 | ||
123 | if (connect(fd, (struct sockaddr *)&sa, sizeof(sa)) == -1) { | |
124 | int e = errno; | |
125 | close(fd); | |
126 | return e; | |
127 | } | |
128 | ||
129 | *out_fd = fd; | |
130 | return 0; | |
131 | } | |
132 | ||
133 | #define TR2_DST_UDS_TRY_STREAM (1 << 0) | |
134 | #define TR2_DST_UDS_TRY_DGRAM (1 << 1) | |
135 | ||
136 | static int tr2_dst_try_unix_domain_socket(struct tr2_dst *dst, | |
137 | const char *tgt_value) | |
138 | { | |
139 | unsigned int uds_try = 0; | |
140 | int fd; | |
141 | int e; | |
142 | const char *path = NULL; | |
143 | ||
144 | /* | |
145 | * Allow "af_unix:[<type>:]<absolute_path>" | |
146 | * | |
147 | * Trace2 always writes complete individual messages (without | |
148 | * chunking), so we can talk to either DGRAM or STREAM type sockets. | |
149 | * | |
150 | * Allow the user to explicitly request the socket type. | |
151 | * | |
152 | * If they omit the socket type, try one and then the other. | |
153 | */ | |
154 | ||
155 | if (skip_prefix(tgt_value, PREFIX_AF_UNIX_STREAM, &path)) | |
156 | uds_try |= TR2_DST_UDS_TRY_STREAM; | |
157 | ||
158 | else if (skip_prefix(tgt_value, PREFIX_AF_UNIX_DGRAM, &path)) | |
159 | uds_try |= TR2_DST_UDS_TRY_DGRAM; | |
160 | ||
161 | else if (skip_prefix(tgt_value, PREFIX_AF_UNIX, &path)) | |
162 | uds_try |= TR2_DST_UDS_TRY_STREAM | TR2_DST_UDS_TRY_DGRAM; | |
163 | ||
164 | if (!path || !*path) { | |
165 | if (tr2_dst_want_warning()) | |
166 | warning("trace2: invalid AF_UNIX value '%s' for '%s' tracing", | |
bce9db6d JH |
167 | tgt_value, |
168 | tr2_sysenv_display_name(dst->sysenv_var)); | |
ee4512ed JH |
169 | |
170 | tr2_dst_trace_disable(dst); | |
171 | return 0; | |
172 | } | |
173 | ||
174 | if (!is_absolute_path(path) || | |
175 | strlen(path) >= sizeof(((struct sockaddr_un *)0)->sun_path)) { | |
176 | if (tr2_dst_want_warning()) | |
177 | warning("trace2: invalid AF_UNIX path '%s' for '%s' tracing", | |
bce9db6d | 178 | path, tr2_sysenv_display_name(dst->sysenv_var)); |
ee4512ed JH |
179 | |
180 | tr2_dst_trace_disable(dst); | |
181 | return 0; | |
182 | } | |
183 | ||
184 | if (uds_try & TR2_DST_UDS_TRY_STREAM) { | |
185 | e = tr2_dst_try_uds_connect(path, SOCK_STREAM, &fd); | |
186 | if (!e) | |
187 | goto connected; | |
188 | if (e != EPROTOTYPE) | |
189 | goto error; | |
190 | } | |
191 | if (uds_try & TR2_DST_UDS_TRY_DGRAM) { | |
192 | e = tr2_dst_try_uds_connect(path, SOCK_DGRAM, &fd); | |
193 | if (!e) | |
194 | goto connected; | |
195 | } | |
196 | ||
197 | error: | |
198 | if (tr2_dst_want_warning()) | |
199 | warning("trace2: could not connect to socket '%s' for '%s' tracing: %s", | |
bce9db6d JH |
200 | path, tr2_sysenv_display_name(dst->sysenv_var), |
201 | strerror(e)); | |
ee4512ed JH |
202 | |
203 | tr2_dst_trace_disable(dst); | |
204 | return 0; | |
205 | ||
206 | connected: | |
207 | dst->fd = fd; | |
208 | dst->need_close = 1; | |
209 | dst->initialized = 1; | |
210 | ||
211 | return dst->fd; | |
212 | } | |
213 | #endif | |
214 | ||
215 | static void tr2_dst_malformed_warning(struct tr2_dst *dst, | |
216 | const char *tgt_value) | |
217 | { | |
218 | struct strbuf buf = STRBUF_INIT; | |
219 | ||
220 | strbuf_addf(&buf, "trace2: unknown value for '%s': '%s'", | |
bce9db6d | 221 | tr2_sysenv_display_name(dst->sysenv_var), tgt_value); |
ee4512ed JH |
222 | warning("%s", buf.buf); |
223 | ||
224 | strbuf_release(&buf); | |
225 | } | |
226 | ||
227 | int tr2_dst_get_trace_fd(struct tr2_dst *dst) | |
228 | { | |
229 | const char *tgt_value; | |
230 | ||
231 | /* don't open twice */ | |
232 | if (dst->initialized) | |
233 | return dst->fd; | |
234 | ||
235 | dst->initialized = 1; | |
236 | ||
bce9db6d | 237 | tgt_value = tr2_sysenv_get(dst->sysenv_var); |
ee4512ed JH |
238 | |
239 | if (!tgt_value || !strcmp(tgt_value, "") || !strcmp(tgt_value, "0") || | |
240 | !strcasecmp(tgt_value, "false")) { | |
241 | dst->fd = 0; | |
242 | return dst->fd; | |
243 | } | |
244 | ||
245 | if (!strcmp(tgt_value, "1") || !strcasecmp(tgt_value, "true")) { | |
246 | dst->fd = STDERR_FILENO; | |
247 | return dst->fd; | |
248 | } | |
249 | ||
250 | if (strlen(tgt_value) == 1 && isdigit(*tgt_value)) { | |
251 | dst->fd = atoi(tgt_value); | |
252 | return dst->fd; | |
253 | } | |
254 | ||
a4d3a283 JS |
255 | if (is_absolute_path(tgt_value)) { |
256 | if (is_directory(tgt_value)) | |
257 | return tr2_dst_try_auto_path(dst, tgt_value); | |
258 | else | |
259 | return tr2_dst_try_path(dst, tgt_value); | |
260 | } | |
ee4512ed JH |
261 | |
262 | #ifndef NO_UNIX_SOCKETS | |
263 | if (starts_with(tgt_value, PREFIX_AF_UNIX)) | |
264 | return tr2_dst_try_unix_domain_socket(dst, tgt_value); | |
265 | #endif | |
266 | ||
267 | /* Always warn about malformed values. */ | |
268 | tr2_dst_malformed_warning(dst, tgt_value); | |
269 | tr2_dst_trace_disable(dst); | |
270 | return 0; | |
271 | } | |
272 | ||
273 | int tr2_dst_trace_want(struct tr2_dst *dst) | |
274 | { | |
275 | return !!tr2_dst_get_trace_fd(dst); | |
276 | } | |
277 | ||
278 | void tr2_dst_write_line(struct tr2_dst *dst, struct strbuf *buf_line) | |
279 | { | |
280 | int fd = tr2_dst_get_trace_fd(dst); | |
281 | ||
282 | strbuf_complete_line(buf_line); /* ensure final NL on buffer */ | |
283 | ||
284 | /* | |
285 | * We do not use write_in_full() because we do not want | |
286 | * a short-write to try again. We are using O_APPEND mode | |
287 | * files and the kernel handles the atomic seek+write. If | |
288 | * another thread or git process is concurrently writing to | |
289 | * this fd or file, our remainder-write may not be contiguous | |
290 | * with our initial write of this message. And that will | |
291 | * confuse readers. So just don't bother. | |
292 | * | |
293 | * It is assumed that TRACE2 messages are short enough that | |
294 | * the system can write them in 1 attempt and we won't see | |
295 | * a short-write. | |
296 | * | |
297 | * If we get an IO error, just close the trace dst. | |
298 | */ | |
299 | if (write(fd, buf_line->buf, buf_line->len) >= 0) | |
300 | return; | |
301 | ||
302 | if (tr2_dst_want_warning()) | |
bce9db6d JH |
303 | warning("unable to write trace to '%s': %s", |
304 | tr2_sysenv_display_name(dst->sysenv_var), | |
ee4512ed JH |
305 | strerror(errno)); |
306 | tr2_dst_trace_disable(dst); | |
307 | } |