1#include "cache.h"
2#include "pkt-line.h"
3#include "run-command.h"
4
5char packet_buffer[LARGE_PACKET_MAX];
6static const char *packet_trace_prefix = "git";
7static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
8static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
9
10void packet_trace_identity(const char *prog)
11{
12 packet_trace_prefix = xstrdup(prog);
13}
14
15static const char *get_trace_prefix(void)
16{
17 return in_async() ? "sideband" : packet_trace_prefix;
18}
19
20static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
21{
22 if (!sideband) {
23 trace_verbatim(&trace_pack, buf, len);
24 return 1;
25 } else if (len && *buf == '\1') {
26 trace_verbatim(&trace_pack, buf + 1, len - 1);
27 return 1;
28 } else {
29 /* it's another non-pack sideband */
30 return 0;
31 }
32}
33
34static void packet_trace(const char *buf, unsigned int len, int write)
35{
36 int i;
37 struct strbuf out;
38 static int in_pack, sideband;
39
40 if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
41 return;
42
43 if (in_pack) {
44 if (packet_trace_pack(buf, len, sideband))
45 return;
46 } else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
47 in_pack = 1;
48 sideband = *buf == '\1';
49 packet_trace_pack(buf, len, sideband);
50
51 /*
52 * Make a note in the human-readable trace that the pack data
53 * started.
54 */
55 buf = "PACK ...";
56 len = strlen(buf);
57 }
58
59 if (!trace_want(&trace_packet))
60 return;
61
62 /* +32 is just a guess for header + quoting */
63 strbuf_init(&out, len+32);
64
65 strbuf_addf(&out, "packet: %12s%c ",
66 get_trace_prefix(), write ? '>' : '<');
67
68 /* XXX we should really handle printable utf8 */
69 for (i = 0; i < len; i++) {
70 /* suppress newlines */
71 if (buf[i] == '\n')
72 continue;
73 if (buf[i] >= 0x20 && buf[i] <= 0x7e)
74 strbuf_addch(&out, buf[i]);
75 else
76 strbuf_addf(&out, "\\%o", buf[i]);
77 }
78
79 strbuf_addch(&out, '\n');
80 trace_strbuf(&trace_packet, &out);
81 strbuf_release(&out);
82}
83
84/*
85 * If we buffered things up above (we don't, but we should),
86 * we'd flush it here
87 */
88void packet_flush(int fd)
89{
90 packet_trace("0000", 4, 1);
91 write_or_die(fd, "0000", 4);
92}
93
94int packet_flush_gently(int fd)
95{
96 packet_trace("0000", 4, 1);
97 if (write_in_full(fd, "0000", 4) == 4)
98 return 0;
99 return error("flush packet write failed");
100}
101
102void packet_buf_flush(struct strbuf *buf)
103{
104 packet_trace("0000", 4, 1);
105 strbuf_add(buf, "0000", 4);
106}
107
108static void set_packet_header(char *buf, const int size)
109{
110 static char hexchar[] = "0123456789abcdef";
111
112 #define hex(a) (hexchar[(a) & 15])
113 buf[0] = hex(size >> 12);
114 buf[1] = hex(size >> 8);
115 buf[2] = hex(size >> 4);
116 buf[3] = hex(size);
117 #undef hex
118}
119
120static void format_packet(struct strbuf *out, const char *fmt, va_list args)
121{
122 size_t orig_len, n;
123
124 orig_len = out->len;
125 strbuf_addstr(out, "0000");
126 strbuf_vaddf(out, fmt, args);
127 n = out->len - orig_len;
128
129 if (n > LARGE_PACKET_MAX)
130 die("protocol error: impossibly long line");
131
132 set_packet_header(&out->buf[orig_len], n);
133 packet_trace(out->buf + orig_len + 4, n - 4, 1);
134}
135
136static int packet_write_fmt_1(int fd, int gently,
137 const char *fmt, va_list args)
138{
139 struct strbuf buf = STRBUF_INIT;
140 ssize_t count;
141
142 format_packet(&buf, fmt, args);
143 count = write_in_full(fd, buf.buf, buf.len);
144 if (count == buf.len)
145 return 0;
146
147 if (!gently) {
148 check_pipe(errno);
149 die_errno("packet write with format failed");
150 }
151 return error("packet write with format failed");
152}
153
154void packet_write_fmt(int fd, const char *fmt, ...)
155{
156 va_list args;
157
158 va_start(args, fmt);
159 packet_write_fmt_1(fd, 0, fmt, args);
160 va_end(args);
161}
162
163int packet_write_fmt_gently(int fd, const char *fmt, ...)
164{
165 int status;
166 va_list args;
167
168 va_start(args, fmt);
169 status = packet_write_fmt_1(fd, 1, fmt, args);
170 va_end(args);
171 return status;
172}
173
174static int packet_write_gently(const int fd_out, const char *buf, size_t size)
175{
176 static char packet_write_buffer[LARGE_PACKET_MAX];
177 size_t packet_size;
178
179 if (size > sizeof(packet_write_buffer) - 4)
180 return error("packet write failed - data exceeds max packet size");
181
182 packet_trace(buf, size, 1);
183 packet_size = size + 4;
184 set_packet_header(packet_write_buffer, packet_size);
185 memcpy(packet_write_buffer + 4, buf, size);
186 if (write_in_full(fd_out, packet_write_buffer, packet_size) == packet_size)
187 return 0;
188 return error("packet write failed");
189}
190
191void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
192{
193 va_list args;
194
195 va_start(args, fmt);
196 format_packet(buf, fmt, args);
197 va_end(args);
198}
199
200static int get_packet_data(int fd, char **src_buf, size_t *src_size,
201 void *dst, unsigned size, int options)
202{
203 ssize_t ret;
204
205 if (fd >= 0 && src_buf && *src_buf)
206 die("BUG: multiple sources given to packet_read");
207
208 /* Read up to "size" bytes from our source, whatever it is. */
209 if (src_buf && *src_buf) {
210 ret = size < *src_size ? size : *src_size;
211 memcpy(dst, *src_buf, ret);
212 *src_buf += ret;
213 *src_size -= ret;
214 } else {
215 ret = read_in_full(fd, dst, size);
216 if (ret < 0)
217 die_errno("read error");
218 }
219
220 /* And complain if we didn't get enough bytes to satisfy the read. */
221 if (ret < size) {
222 if (options & PACKET_READ_GENTLE_ON_EOF)
223 return -1;
224
225 die("The remote end hung up unexpectedly");
226 }
227
228 return ret;
229}
230
231static int packet_length(const char *linelen)
232{
233 int val = hex2chr(linelen);
234 return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
235}
236
237int packet_read(int fd, char **src_buf, size_t *src_len,
238 char *buffer, unsigned size, int options)
239{
240 int len, ret;
241 char linelen[4];
242
243 ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
244 if (ret < 0)
245 return ret;
246 len = packet_length(linelen);
247 if (len < 0)
248 die("protocol error: bad line length character: %.4s", linelen);
249 if (!len) {
250 packet_trace("0000", 4, 0);
251 return 0;
252 }
253 len -= 4;
254 if (len >= size)
255 die("protocol error: bad line length %d", len);
256 ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
257 if (ret < 0)
258 return ret;
259
260 if ((options & PACKET_READ_CHOMP_NEWLINE) &&
261 len && buffer[len-1] == '\n')
262 len--;
263
264 buffer[len] = 0;
265 packet_trace(buffer, len, 0);
266 return len;
267}
268
269static char *packet_read_line_generic(int fd,
270 char **src, size_t *src_len,
271 int *dst_len)
272{
273 int len = packet_read(fd, src, src_len,
274 packet_buffer, sizeof(packet_buffer),
275 PACKET_READ_CHOMP_NEWLINE);
276 if (dst_len)
277 *dst_len = len;
278 return len ? packet_buffer : NULL;
279}
280
281char *packet_read_line(int fd, int *len_p)
282{
283 return packet_read_line_generic(fd, NULL, NULL, len_p);
284}
285
286char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
287{
288 return packet_read_line_generic(-1, src, src_len, dst_len);
289}