encode_in_pack_object_header: respect output buffer length
[git/git.git] / pack.h
CommitLineData
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1#ifndef PACK_H
2#define PACK_H
3
1974632c 4#include "object.h"
c0ad4657 5#include "csum-file.h"
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6
7/*
8 * Packed object header
9 */
10#define PACK_SIGNATURE 0x5041434b /* "PACK" */
29f049a0 11#define PACK_VERSION 2
d60fc1c8 12#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
a733cb60 13struct pack_header {
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14 uint32_t hdr_signature;
15 uint32_t hdr_version;
16 uint32_t hdr_entries;
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17};
18
df1b059d 19/*
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20 * The first four bytes of index formats later than version 1 should
21 * start with this signature, as all older git binaries would find this
22 * value illegal and abort reading the file.
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23 *
24 * This is the case because the number of objects in a packfile
25 * cannot exceed 1,431,660,000 as every object would need at least
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26 * 3 bytes of data and the overall packfile cannot exceed 4 GiB with
27 * version 1 of the index file due to the offsets limited to 32 bits.
28 * Clearly the signature exceeds this maximum.
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29 *
30 * Very old git binaries will also compare the first 4 bytes to the
31 * next 4 bytes in the index and abort with a "non-monotonic index"
32 * error if the second 4 byte word is smaller than the first 4
33 * byte word. This would be true in the proposed future index
34 * format as idx_signature would be greater than idx_version.
35 */
36#define PACK_IDX_SIGNATURE 0xff744f63 /* "\377tOc" */
37
ebcfb379 38struct pack_idx_option {
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JH
39 unsigned flags;
40 /* flag bits */
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JH
41#define WRITE_IDX_VERIFY 01 /* verify only, do not write the idx file */
42#define WRITE_IDX_STRICT 02
e337a04d 43
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44 uint32_t version;
45 uint32_t off32_limit;
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46
47 /*
48 * List of offsets that would fit within off32_limit but
49 * need to be written out as 64-bit entity for byte-for-byte
50 * verification.
51 */
52 int anomaly_alloc, anomaly_nr;
53 uint32_t *anomaly;
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JH
54};
55
56extern void reset_pack_idx_option(struct pack_idx_option *);
aa7e44bf 57
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58/*
59 * Packed object index header
60 */
61struct pack_idx_header {
62 uint32_t idx_signature;
63 uint32_t idx_version;
64};
65
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66/*
67 * Common part of object structure used for write_idx_file
68 */
69struct pack_idx_entry {
70 unsigned char sha1[20];
71 uint32_t crc32;
72 off_t offset;
73};
74
c9486eb0 75
1e49f22f 76struct progress;
ec9d2249 77/* Note, the data argument could be NULL if object type is blob */
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78typedef int (*verify_fn)(const unsigned char*, enum object_type, unsigned long, void*, int*);
79
1190a1ac 80extern const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, const unsigned char *sha1);
c41a4a94 81extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
9b0aa728 82extern int verify_pack_index(struct packed_git *);
1e49f22f 83extern int verify_pack(struct packed_git *, verify_fn fn, struct progress *, uint32_t);
c0ad4657 84extern off_t write_pack_header(struct sha1file *f, uint32_t);
abeb40e5 85extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
106764e6 86extern char *index_pack_lockfile(int fd);
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87extern int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
88 enum object_type, uintmax_t);
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89
90#define PH_ERROR_EOF (-1)
91#define PH_ERROR_PACK_SIGNATURE (-2)
92#define PH_ERROR_PROTOCOL (-3)
93extern int read_pack_header(int fd, struct pack_header *);
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94
95extern struct sha1file *create_tmp_packfile(char **pack_tmp_name);
58892711 96extern void finish_tmp_packfile(struct strbuf *name_buffer, const char *pack_tmp_name, struct pack_idx_entry **written_list, uint32_t nr_written, struct pack_idx_option *pack_idx_opts, unsigned char sha1[]);
cdf9db3c 97
a733cb60 98#endif