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pgtar.h File Reference
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Enumerations

enum  tarError { TAR_OK = 0, TAR_NAME_TOO_LONG, TAR_SYMLINK_TOO_LONG }
 

Functions

enum tarError tarCreateHeader (char *h, const char *filename, const char *linktarget, pgoff_t size, mode_t mode, uid_t uid, gid_t gid, time_t mtime)
 
uint64 read_tar_number (const char *s, int len)
 
void print_tar_number (char *s, int len, uint64 val)
 
int tarChecksum (char *header)
 

Enumeration Type Documentation

◆ tarError

enum tarError
Enumerator
TAR_OK 
TAR_NAME_TOO_LONG 
TAR_SYMLINK_TOO_LONG 

Definition at line 15 of file pgtar.h.

Function Documentation

◆ print_tar_number()

void print_tar_number ( char *  s,
int  len,
uint64  val 
)

Definition at line 22 of file tar.c.

Referenced by tar_close(), and tarCreateHeader().

23 {
24  if (val < (((uint64) 1) << ((len - 1) * 3)))
25  {
26  /* Use octal with trailing space */
27  s[--len] = ' ';
28  while (len)
29  {
30  s[--len] = (val & 7) + '0';
31  val >>= 3;
32  }
33  }
34  else
35  {
36  /* Use base-256 with leading \200 */
37  s[0] = '\200';
38  while (len > 1)
39  {
40  s[--len] = (val & 255);
41  val >>= 8;
42  }
43  }
44 }
long val
Definition: informix.c:664

◆ read_tar_number()

uint64 read_tar_number ( const char *  s,
int  len 
)

Definition at line 58 of file tar.c.

Referenced by _tarGetHeader(), isValidTarHeader(), ReceiveTarAndUnpackCopyChunk(), and ReceiveTarCopyChunk().

59 {
60  uint64 result = 0;
61 
62  if (*s == '\200')
63  {
64  /* base-256 */
65  while (--len)
66  {
67  result <<= 8;
68  result |= (unsigned char) (*++s);
69  }
70  }
71  else
72  {
73  /* octal */
74  while (len-- && *s >= '0' && *s <= '7')
75  {
76  result <<= 3;
77  result |= (*s - '0');
78  s++;
79  }
80  }
81  return result;
82 }

◆ tarChecksum()

int tarChecksum ( char *  header)

Definition at line 90 of file tar.c.

References i.

Referenced by _tarGetHeader(), isValidTarHeader(), tar_close(), and tarCreateHeader().

91 {
92  int i,
93  sum;
94 
95  /*
96  * Per POSIX, the checksum is the simple sum of all bytes in the header,
97  * treating the bytes as unsigned, and treating the checksum field (at
98  * offset 148) as though it contained 8 spaces.
99  */
100  sum = 8 * ' '; /* presumed value for checksum field */
101  for (i = 0; i < 512; i++)
102  if (i < 148 || i >= 156)
103  sum += 0xFF & header[i];
104  return sum;
105 }
static void header(const char *fmt,...) pg_attribute_printf(1
Definition: pg_regress.c:209
int i

◆ tarCreateHeader()

enum tarError tarCreateHeader ( char *  h,
const char *  filename,
const char *  linktarget,
pgoff_t  size,
mode_t  mode,
uid_t  uid,
gid_t  gid,
time_t  mtime 
)

Definition at line 114 of file tar.c.

References Min, print_tar_number(), S_ISDIR, strlcpy(), TAR_NAME_TOO_LONG, TAR_OK, TAR_SYMLINK_TOO_LONG, and tarChecksum().

Referenced by _tarWriteHeader(), ReceiveTarCopyChunk(), ReceiveTarFile(), and tar_open_for_write().

116 {
117  if (strlen(filename) > 99)
118  return TAR_NAME_TOO_LONG;
119 
120  if (linktarget && strlen(linktarget) > 99)
121  return TAR_SYMLINK_TOO_LONG;
122 
123  memset(h, 0, 512); /* assume tar header size */
124 
125  /* Name 100 */
126  strlcpy(&h[0], filename, 100);
127  if (linktarget != NULL || S_ISDIR(mode))
128  {
129  /*
130  * We only support symbolic links to directories, and this is
131  * indicated in the tar format by adding a slash at the end of the
132  * name, the same as for regular directories.
133  */
134  int flen = strlen(filename);
135 
136  flen = Min(flen, 99);
137  h[flen] = '/';
138  h[flen + 1] = '\0';
139  }
140 
141  /* Mode 8 - this doesn't include the file type bits (S_IFMT) */
142  print_tar_number(&h[100], 8, (mode & 07777));
143 
144  /* User ID 8 */
145  print_tar_number(&h[108], 8, uid);
146 
147  /* Group 8 */
148  print_tar_number(&h[116], 8, gid);
149 
150  /* File size 12 */
151  if (linktarget != NULL || S_ISDIR(mode))
152  /* Symbolic link or directory has size zero */
153  print_tar_number(&h[124], 12, 0);
154  else
155  print_tar_number(&h[124], 12, size);
156 
157  /* Mod Time 12 */
158  print_tar_number(&h[136], 12, mtime);
159 
160  /* Checksum 8 cannot be calculated until we've filled all other fields */
161 
162  if (linktarget != NULL)
163  {
164  /* Type - Symbolic link */
165  h[156] = '2';
166  /* Link Name 100 */
167  strlcpy(&h[157], linktarget, 100);
168  }
169  else if (S_ISDIR(mode))
170  {
171  /* Type - directory */
172  h[156] = '5';
173  }
174  else
175  {
176  /* Type - regular file */
177  h[156] = '0';
178  }
179 
180  /* Magic 6 */
181  strcpy(&h[257], "ustar");
182 
183  /* Version 2 */
184  memcpy(&h[263], "00", 2);
185 
186  /* User 32 */
187  /* XXX: Do we need to care about setting correct username? */
188  strlcpy(&h[265], "postgres", 32);
189 
190  /* Group 32 */
191  /* XXX: Do we need to care about setting correct group name? */
192  strlcpy(&h[297], "postgres", 32);
193 
194  /* Major Dev 8 */
195  print_tar_number(&h[329], 8, 0);
196 
197  /* Minor Dev 8 */
198  print_tar_number(&h[337], 8, 0);
199 
200  /* Prefix 155 - not used, leave as nulls */
201 
202  /* Finally, compute and insert the checksum */
203  print_tar_number(&h[148], 8, tarChecksum(h));
204 
205  return TAR_OK;
206 }
int tarChecksum(char *header)
Definition: tar.c:90
static PgChecksumMode mode
Definition: pg_checksums.c:61
Definition: pgtar.h:17
#define Min(x, y)
Definition: c.h:911
void print_tar_number(char *s, int len, uint64 val)
Definition: tar.c:22
size_t strlcpy(char *dst, const char *src, size_t siz)
Definition: strlcpy.c:45
#define S_ISDIR(m)
Definition: win32_port.h:296
static char * filename
Definition: pg_dumpall.c:90