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Commit | Line | Data |
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f3a3214e LT |
1 | #include "cache.h" |
2 | #include "pkt-line.h" | |
3 | ||
1e4cd68c | 4 | static const char *packet_trace_prefix = "git"; |
bbc30f99 JK |
5 | static const char trace_key[] = "GIT_TRACE_PACKET"; |
6 | ||
7 | void packet_trace_identity(const char *prog) | |
8 | { | |
9 | packet_trace_prefix = xstrdup(prog); | |
10 | } | |
11 | ||
12 | static void packet_trace(const char *buf, unsigned int len, int write) | |
13 | { | |
14 | int i; | |
15 | struct strbuf out; | |
16 | ||
17 | if (!trace_want(trace_key)) | |
18 | return; | |
19 | ||
20 | /* +32 is just a guess for header + quoting */ | |
21 | strbuf_init(&out, len+32); | |
22 | ||
23 | strbuf_addf(&out, "packet: %12s%c ", | |
24 | packet_trace_prefix, write ? '>' : '<'); | |
25 | ||
26 | if ((len >= 4 && !prefixcmp(buf, "PACK")) || | |
27 | (len >= 5 && !prefixcmp(buf+1, "PACK"))) { | |
28 | strbuf_addstr(&out, "PACK ..."); | |
29 | unsetenv(trace_key); | |
30 | } | |
31 | else { | |
32 | /* XXX we should really handle printable utf8 */ | |
33 | for (i = 0; i < len; i++) { | |
34 | /* suppress newlines */ | |
35 | if (buf[i] == '\n') | |
36 | continue; | |
37 | if (buf[i] >= 0x20 && buf[i] <= 0x7e) | |
38 | strbuf_addch(&out, buf[i]); | |
39 | else | |
40 | strbuf_addf(&out, "\\%o", buf[i]); | |
41 | } | |
42 | } | |
43 | ||
44 | strbuf_addch(&out, '\n'); | |
45 | trace_strbuf(trace_key, &out); | |
46 | strbuf_release(&out); | |
47 | } | |
48 | ||
f3a3214e LT |
49 | /* |
50 | * Write a packetized stream, where each line is preceded by | |
51 | * its length (including the header) as a 4-byte hex number. | |
52 | * A length of 'zero' means end of stream (and a length of 1-3 | |
a6080a0a | 53 | * would be an error). |
f3a3214e LT |
54 | * |
55 | * This is all pretty stupid, but we use this packetized line | |
56 | * format to make a streaming format possible without ever | |
57 | * over-running the read buffers. That way we'll never read | |
58 | * into what might be the pack data (which should go to another | |
59 | * process entirely). | |
60 | * | |
61 | * The writing side could use stdio, but since the reading | |
62 | * side can't, we stay with pure read/write interfaces. | |
63 | */ | |
583b7ea3 | 64 | ssize_t safe_write(int fd, const void *buf, ssize_t n) |
f3a3214e | 65 | { |
583b7ea3 | 66 | ssize_t nn = n; |
f3a3214e | 67 | while (n) { |
1c15afb9 | 68 | int ret = xwrite(fd, buf, n); |
f3a3214e | 69 | if (ret > 0) { |
1d7f171c | 70 | buf = (char *) buf + ret; |
f3a3214e LT |
71 | n -= ret; |
72 | continue; | |
73 | } | |
74 | if (!ret) | |
75 | die("write error (disk full?)"); | |
d824cbba | 76 | die_errno("write error"); |
f3a3214e | 77 | } |
583b7ea3 | 78 | return nn; |
f3a3214e LT |
79 | } |
80 | ||
81 | /* | |
82 | * If we buffered things up above (we don't, but we should), | |
83 | * we'd flush it here | |
84 | */ | |
85 | void packet_flush(int fd) | |
86 | { | |
bbc30f99 | 87 | packet_trace("0000", 4, 1); |
f3a3214e LT |
88 | safe_write(fd, "0000", 4); |
89 | } | |
90 | ||
f5615d24 SP |
91 | void packet_buf_flush(struct strbuf *buf) |
92 | { | |
bbc30f99 | 93 | packet_trace("0000", 4, 1); |
f5615d24 SP |
94 | strbuf_add(buf, "0000", 4); |
95 | } | |
96 | ||
f3a3214e | 97 | #define hex(a) (hexchar[(a) & 15]) |
f5615d24 SP |
98 | static char buffer[1000]; |
99 | static unsigned format_packet(const char *fmt, va_list args) | |
f3a3214e | 100 | { |
f3a3214e | 101 | static char hexchar[] = "0123456789abcdef"; |
f3a3214e LT |
102 | unsigned n; |
103 | ||
f3a3214e | 104 | n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args); |
f3a3214e LT |
105 | if (n >= sizeof(buffer)-4) |
106 | die("protocol error: impossibly long line"); | |
107 | n += 4; | |
108 | buffer[0] = hex(n >> 12); | |
109 | buffer[1] = hex(n >> 8); | |
110 | buffer[2] = hex(n >> 4); | |
111 | buffer[3] = hex(n); | |
bbc30f99 | 112 | packet_trace(buffer+4, n-4, 1); |
f5615d24 SP |
113 | return n; |
114 | } | |
115 | ||
116 | void packet_write(int fd, const char *fmt, ...) | |
117 | { | |
118 | va_list args; | |
119 | unsigned n; | |
120 | ||
121 | va_start(args, fmt); | |
122 | n = format_packet(fmt, args); | |
123 | va_end(args); | |
f3a3214e LT |
124 | safe_write(fd, buffer, n); |
125 | } | |
126 | ||
f5615d24 SP |
127 | void packet_buf_write(struct strbuf *buf, const char *fmt, ...) |
128 | { | |
129 | va_list args; | |
130 | unsigned n; | |
131 | ||
132 | va_start(args, fmt); | |
133 | n = format_packet(fmt, args); | |
134 | va_end(args); | |
135 | strbuf_add(buf, buffer, n); | |
136 | } | |
137 | ||
46284dd1 | 138 | static int safe_read(int fd, void *buffer, unsigned size, int return_line_fail) |
f3a3214e | 139 | { |
c697ad14 HO |
140 | ssize_t ret = read_in_full(fd, buffer, size); |
141 | if (ret < 0) | |
d824cbba | 142 | die_errno("read error"); |
46284dd1 HV |
143 | else if (ret < size) { |
144 | if (return_line_fail) | |
145 | return -1; | |
146 | ||
c697ad14 | 147 | die("The remote end hung up unexpectedly"); |
46284dd1 HV |
148 | } |
149 | ||
150 | return ret; | |
f3a3214e LT |
151 | } |
152 | ||
f5615d24 | 153 | static int packet_length(const char *linelen) |
f3a3214e LT |
154 | { |
155 | int n; | |
f5615d24 | 156 | int len = 0; |
f3a3214e | 157 | |
f3a3214e LT |
158 | for (n = 0; n < 4; n++) { |
159 | unsigned char c = linelen[n]; | |
160 | len <<= 4; | |
161 | if (c >= '0' && c <= '9') { | |
162 | len += c - '0'; | |
163 | continue; | |
164 | } | |
165 | if (c >= 'a' && c <= 'f') { | |
166 | len += c - 'a' + 10; | |
167 | continue; | |
168 | } | |
169 | if (c >= 'A' && c <= 'F') { | |
170 | len += c - 'A' + 10; | |
171 | continue; | |
172 | } | |
f5615d24 | 173 | return -1; |
f3a3214e | 174 | } |
f5615d24 SP |
175 | return len; |
176 | } | |
177 | ||
46284dd1 | 178 | static int packet_read_internal(int fd, char *buffer, unsigned size, int return_line_fail) |
f5615d24 | 179 | { |
46284dd1 | 180 | int len, ret; |
f5615d24 SP |
181 | char linelen[4]; |
182 | ||
46284dd1 HV |
183 | ret = safe_read(fd, linelen, 4, return_line_fail); |
184 | if (return_line_fail && ret < 0) | |
185 | return ret; | |
f5615d24 SP |
186 | len = packet_length(linelen); |
187 | if (len < 0) | |
743c4b7b | 188 | die("protocol error: bad line length character: %.4s", linelen); |
bbc30f99 JK |
189 | if (!len) { |
190 | packet_trace("0000", 4, 0); | |
f3a3214e | 191 | return 0; |
bbc30f99 | 192 | } |
f3a3214e LT |
193 | len -= 4; |
194 | if (len >= size) | |
195 | die("protocol error: bad line length %d", len); | |
46284dd1 HV |
196 | ret = safe_read(fd, buffer, len, return_line_fail); |
197 | if (return_line_fail && ret < 0) | |
198 | return ret; | |
f3a3214e | 199 | buffer[len] = 0; |
bbc30f99 | 200 | packet_trace(buffer, len, 0); |
f3a3214e LT |
201 | return len; |
202 | } | |
f5615d24 | 203 | |
46284dd1 HV |
204 | int packet_read(int fd, char *buffer, unsigned size) |
205 | { | |
206 | return packet_read_internal(fd, buffer, size, 1); | |
207 | } | |
208 | ||
209 | int packet_read_line(int fd, char *buffer, unsigned size) | |
210 | { | |
211 | return packet_read_internal(fd, buffer, size, 0); | |
212 | } | |
213 | ||
f5615d24 SP |
214 | int packet_get_line(struct strbuf *out, |
215 | char **src_buf, size_t *src_len) | |
216 | { | |
217 | int len; | |
218 | ||
219 | if (*src_len < 4) | |
220 | return -1; | |
221 | len = packet_length(*src_buf); | |
222 | if (len < 0) | |
223 | return -1; | |
224 | if (!len) { | |
225 | *src_buf += 4; | |
226 | *src_len -= 4; | |
bbc30f99 | 227 | packet_trace("0000", 4, 0); |
f5615d24 SP |
228 | return 0; |
229 | } | |
230 | if (*src_len < len) | |
231 | return -2; | |
232 | ||
233 | *src_buf += 4; | |
234 | *src_len -= 4; | |
235 | len -= 4; | |
236 | ||
237 | strbuf_add(out, *src_buf, len); | |
238 | *src_buf += len; | |
239 | *src_len -= len; | |
bbc30f99 | 240 | packet_trace(out->buf, out->len, 0); |
f5615d24 SP |
241 | return len; |
242 | } |