pkt-line: provide a LARGE_PACKET_MAX static buffer
[git/git.git] / pkt-line.c
CommitLineData
f3a3214e
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1#include "cache.h"
2#include "pkt-line.h"
3
74543a04 4char packet_buffer[LARGE_PACKET_MAX];
1e4cd68c 5static const char *packet_trace_prefix = "git";
bbc30f99
JK
6static const char trace_key[] = "GIT_TRACE_PACKET";
7
8void packet_trace_identity(const char *prog)
9{
10 packet_trace_prefix = xstrdup(prog);
11}
12
13static void packet_trace(const char *buf, unsigned int len, int write)
14{
15 int i;
16 struct strbuf out;
17
18 if (!trace_want(trace_key))
19 return;
20
21 /* +32 is just a guess for header + quoting */
22 strbuf_init(&out, len+32);
23
24 strbuf_addf(&out, "packet: %12s%c ",
25 packet_trace_prefix, write ? '>' : '<');
26
27 if ((len >= 4 && !prefixcmp(buf, "PACK")) ||
28 (len >= 5 && !prefixcmp(buf+1, "PACK"))) {
29 strbuf_addstr(&out, "PACK ...");
30 unsetenv(trace_key);
31 }
32 else {
33 /* XXX we should really handle printable utf8 */
34 for (i = 0; i < len; i++) {
35 /* suppress newlines */
36 if (buf[i] == '\n')
37 continue;
38 if (buf[i] >= 0x20 && buf[i] <= 0x7e)
39 strbuf_addch(&out, buf[i]);
40 else
41 strbuf_addf(&out, "\\%o", buf[i]);
42 }
43 }
44
45 strbuf_addch(&out, '\n');
46 trace_strbuf(trace_key, &out);
47 strbuf_release(&out);
48}
49
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50/*
51 * If we buffered things up above (we don't, but we should),
52 * we'd flush it here
53 */
54void packet_flush(int fd)
55{
bbc30f99 56 packet_trace("0000", 4, 1);
cdf4fb8e 57 write_or_die(fd, "0000", 4);
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LT
58}
59
f5615d24
SP
60void packet_buf_flush(struct strbuf *buf)
61{
bbc30f99 62 packet_trace("0000", 4, 1);
f5615d24
SP
63 strbuf_add(buf, "0000", 4);
64}
65
f3a3214e 66#define hex(a) (hexchar[(a) & 15])
f5615d24
SP
67static char buffer[1000];
68static unsigned format_packet(const char *fmt, va_list args)
f3a3214e 69{
f3a3214e 70 static char hexchar[] = "0123456789abcdef";
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71 unsigned n;
72
f3a3214e 73 n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args);
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LT
74 if (n >= sizeof(buffer)-4)
75 die("protocol error: impossibly long line");
76 n += 4;
77 buffer[0] = hex(n >> 12);
78 buffer[1] = hex(n >> 8);
79 buffer[2] = hex(n >> 4);
80 buffer[3] = hex(n);
bbc30f99 81 packet_trace(buffer+4, n-4, 1);
f5615d24
SP
82 return n;
83}
84
85void packet_write(int fd, const char *fmt, ...)
86{
87 va_list args;
88 unsigned n;
89
90 va_start(args, fmt);
91 n = format_packet(fmt, args);
92 va_end(args);
cdf4fb8e 93 write_or_die(fd, buffer, n);
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LT
94}
95
f5615d24
SP
96void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
97{
98 va_list args;
99 unsigned n;
100
101 va_start(args, fmt);
102 n = format_packet(fmt, args);
103 va_end(args);
104 strbuf_add(buf, buffer, n);
105}
106
03809429 107static int safe_read(int fd, void *buffer, unsigned size, int options)
f3a3214e 108{
c697ad14
HO
109 ssize_t ret = read_in_full(fd, buffer, size);
110 if (ret < 0)
d824cbba 111 die_errno("read error");
46284dd1 112 else if (ret < size) {
03809429 113 if (options & PACKET_READ_GENTLE_ON_EOF)
46284dd1
HV
114 return -1;
115
c697ad14 116 die("The remote end hung up unexpectedly");
46284dd1
HV
117 }
118
119 return ret;
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120}
121
f5615d24 122static int packet_length(const char *linelen)
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123{
124 int n;
f5615d24 125 int len = 0;
f3a3214e 126
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LT
127 for (n = 0; n < 4; n++) {
128 unsigned char c = linelen[n];
129 len <<= 4;
130 if (c >= '0' && c <= '9') {
131 len += c - '0';
132 continue;
133 }
134 if (c >= 'a' && c <= 'f') {
135 len += c - 'a' + 10;
136 continue;
137 }
138 if (c >= 'A' && c <= 'F') {
139 len += c - 'A' + 10;
140 continue;
141 }
f5615d24 142 return -1;
f3a3214e 143 }
f5615d24
SP
144 return len;
145}
146
03809429 147int packet_read(int fd, char *buffer, unsigned size, int options)
f5615d24 148{
46284dd1 149 int len, ret;
f5615d24
SP
150 char linelen[4];
151
03809429
JK
152 ret = safe_read(fd, linelen, 4, options);
153 if (ret < 0)
46284dd1 154 return ret;
f5615d24
SP
155 len = packet_length(linelen);
156 if (len < 0)
743c4b7b 157 die("protocol error: bad line length character: %.4s", linelen);
bbc30f99
JK
158 if (!len) {
159 packet_trace("0000", 4, 0);
f3a3214e 160 return 0;
bbc30f99 161 }
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162 len -= 4;
163 if (len >= size)
164 die("protocol error: bad line length %d", len);
03809429
JK
165 ret = safe_read(fd, buffer, len, options);
166 if (ret < 0)
46284dd1 167 return ret;
819b929d
JK
168
169 if ((options & PACKET_READ_CHOMP_NEWLINE) &&
170 len && buffer[len-1] == '\n')
171 len--;
172
f3a3214e 173 buffer[len] = 0;
bbc30f99 174 packet_trace(buffer, len, 0);
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LT
175 return len;
176}
f5615d24 177
74543a04 178char *packet_read_line(int fd, int *len_p)
46284dd1 179{
74543a04
JK
180 int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
181 PACKET_READ_CHOMP_NEWLINE);
182 if (len_p)
183 *len_p = len;
184 return len ? packet_buffer : NULL;
46284dd1
HV
185}
186
f5615d24
SP
187int packet_get_line(struct strbuf *out,
188 char **src_buf, size_t *src_len)
189{
190 int len;
191
192 if (*src_len < 4)
193 return -1;
194 len = packet_length(*src_buf);
195 if (len < 0)
196 return -1;
197 if (!len) {
198 *src_buf += 4;
199 *src_len -= 4;
bbc30f99 200 packet_trace("0000", 4, 0);
f5615d24
SP
201 return 0;
202 }
203 if (*src_len < len)
204 return -2;
205
206 *src_buf += 4;
207 *src_len -= 4;
208 len -= 4;
209
210 strbuf_add(out, *src_buf, len);
211 *src_buf += len;
212 *src_len -= len;
bbc30f99 213 packet_trace(out->buf, out->len, 0);
f5615d24
SP
214 return len;
215}