ref: 90143609212ed4500409a64d26f6b12d097b13ed
dir: /sys/src/ape/cmd/pax/extract.c/
/* $Source: /u/mark/src/pax/RCS/extract.c,v $ * * $Revision: 1.3 $ * * extract.c - Extract files from a tar archive. * * DESCRIPTION * * AUTHOR * * Mark H. Colburn, NAPS International ([email protected]) * * Sponsored by The USENIX Association for public distribution. * * Copyright (c) 1989 Mark H. Colburn. * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that the above copyright notice is duplicated in all such * forms and that any documentation, advertising materials, and other * materials related to such distribution and use acknowledge that the * software was developed * by Mark H. Colburn and sponsored by The * USENIX Association. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. * * $Log: extract.c,v $ * Revision 1.3 89/02/12 10:29:43 mark * Fixed misspelling of Replstr * * Revision 1.2 89/02/12 10:04:24 mark * 1.2 release fixes * * Revision 1.1 88/12/23 18:02:07 mark * Initial revision * */ #ifndef lint static char *ident = "$Id: extract.c,v 1.3 89/02/12 10:29:43 mark Exp Locker: mark $"; static char *copyright = "Copyright (c) 1989 Mark H. Colburn.\nAll rights reserved.\n"; #endif /* ! lint */ /* Headers */ #include "pax.h" /* Defines */ /* * Swap bytes. */ #define SWAB(n) ((((ushort)(n) >> 8) & 0xff) | (((ushort)(n) << 8) & 0xff00)) /* Function Prototypes */ #ifdef __STDC__ static int inbinary(char *, char *, Stat *); static int inascii(char *, char *, Stat *); static int inswab(char *, char *, Stat *); static int readtar(char *, Stat *); static int readcpio(char *, Stat *); #else /* !__STDC__ */ static int inbinary(); static int inascii(); static int inswab(); static int readtar(); static int readcpio(); #endif /* __STDC__ */ /* read_archive - read in an archive * * DESCRIPTION * * Read_archive is the central entry point for reading archives. * Read_archive determines the proper archive functions to call * based upon the archive type being processed. * * RETURNS * */ #ifdef __STDC__ int read_archive(void) #else int read_archive() #endif { Stat sb; char name[PATH_MAX + 1]; int match; int pad; name_gather(); /* get names from command line */ name[0] = '\0'; while (get_header(name, &sb) == 0) { match = name_match(name) ^ f_reverse_match; if (f_list) { /* only wanted a table of contents */ if (match) { print_entry(name, &sb); } if (((ar_format == TAR) ? buf_skip(ROUNDUP((OFFSET) sb.sb_size, BLOCKSIZE)) : buf_skip((OFFSET) sb.sb_size)) < 0) { warn(name, "File data is corrupt"); } } else if (match) { if (rplhead != (Replstr *)NULL) { rpl_name(name); if (strlen(name) == 0) { continue; } } if (get_disposition("extract", name) || get_newname(name, sizeof(name))) { /* skip file... */ if (((ar_format == TAR) ? buf_skip(ROUNDUP((OFFSET) sb.sb_size, BLOCKSIZE)) : buf_skip((OFFSET) sb.sb_size)) < 0) { warn(name, "File data is corrupt"); } continue; } if (inentry(name, &sb) < 0) { warn(name, "File data is corrupt"); } if (f_verbose) { print_entry(name, &sb); } if (ar_format == TAR && sb.sb_nlink > 1) { /* * This kludge makes sure that the link table is cleared * before attempting to process any other links. */ if (sb.sb_nlink > 1) { linkfrom(name, &sb); } } if (ar_format == TAR && (pad = sb.sb_size % BLOCKSIZE) != 0) { pad = BLOCKSIZE - pad; buf_skip((OFFSET) pad); } } else { if (((ar_format == TAR) ? buf_skip(ROUNDUP((OFFSET) sb.sb_size, BLOCKSIZE)) : buf_skip((OFFSET) sb.sb_size)) < 0) { warn(name, "File data is corrupt"); } } } close_archive(); } /* get_header - figures which type of header needs to be read. * * DESCRIPTION * * This is merely a single entry point for the two types of archive * headers which are supported. The correct header is selected * depending on the archive type. * * PARAMETERS * * char *name - name of the file (passed to header routine) * Stat *asb - Stat block for the file (passed to header routine) * * RETURNS * * Returns the value which was returned by the proper header * function. */ #ifdef __STDC__ int get_header(char *name, Stat *asb) #else int get_header(name, asb) char *name; Stat *asb; #endif { if (ar_format == TAR) { return(readtar(name, asb)); } else { return(readcpio(name, asb)); } } /* readtar - read a tar header * * DESCRIPTION * * Tar_head read a tar format header from the archive. The name * and asb parameters are modified as appropriate for the file listed * in the header. Name is assumed to be a pointer to an array of * at least PATH_MAX bytes. * * PARAMETERS * * char *name - name of the file for which the header is * for. This is modified and passed back to * the caller. * Stat *asb - Stat block for the file for which the header * is for. The fields of the stat structure are * extracted from the archive header. This is * also passed back to the caller. * * RETURNS * * Returns 0 if a valid header was found, or -1 if EOF is * encountered. */ #ifdef __STDC__ static int readtar(char *name, Stat *asb) #else static int readtar(name, asb) char *name; Stat *asb; #endif { int status = 3; /* Initial status at start of archive */ static int prev_status; for (;;) { prev_status = status; status = read_header(name, asb); switch (status) { case 1: /* Valid header */ return(0); case 0: /* Invalid header */ switch (prev_status) { case 3: /* Error on first record */ warn(ar_file, "This doesn't look like a tar archive"); /* FALLTHRU */ case 2: /* Error after record of zeroes */ case 1: /* Error after header rec */ warn(ar_file, "Skipping to next file..."); /* FALLTHRU */ default: case 0: /* Error after error */ break; } break; case 2: /* Record of zeroes */ case EOF: /* End of archive */ default: return(-1); } } } /* readcpio - read a CPIO header * * DESCRIPTION * * Read in a cpio header. Understands how to determine and read ASCII, * binary and byte-swapped binary headers. Quietly translates * old-fashioned binary cpio headers (and arranges to skip the possible * alignment byte). Returns zero if successful, -1 upon archive trailer. * * PARAMETERS * * char *name - name of the file for which the header is * for. This is modified and passed back to * the caller. * Stat *asb - Stat block for the file for which the header * is for. The fields of the stat structure are * extracted from the archive header. This is * also passed back to the caller. * * RETURNS * * Returns 0 if a valid header was found, or -1 if EOF is * encountered. */ #ifdef __STDC__ static int readcpio(char *name, Stat *asb) #else static int readcpio(name, asb) char *name; Stat *asb; #endif { OFFSET skipped; char magic[M_STRLEN]; static int align; if (align > 0) { buf_skip((OFFSET) align); } align = 0; for (;;) { buf_read(magic, M_STRLEN); skipped = 0; while ((align = inascii(magic, name, asb)) < 0 && (align = inbinary(magic, name, asb)) < 0 && (align = inswab(magic, name, asb)) < 0) { if (++skipped == 1) { if (total - sizeof(magic) == 0) { fatal("Unrecognizable archive"); } warnarch("Bad magic number", (OFFSET) sizeof(magic)); if (name[0]) { warn(name, "May be corrupt"); } } memcpy(magic, magic + 1, sizeof(magic) - 1); buf_read(magic + sizeof(magic) - 1, 1); } if (skipped) { warnarch("Apparently resynchronized", (OFFSET) sizeof(magic)); warn(name, "Continuing"); } if (strcmp(name, TRAILER) == 0) { return (-1); } if (nameopt(name) >= 0) { break; } buf_skip((OFFSET) asb->sb_size + align); } #ifdef S_IFLNK if ((asb->sb_mode & S_IFMT) == S_IFLNK) { if (buf_read(asb->sb_link, (uint) asb->sb_size) < 0) { warn(name, "Corrupt symbolic link"); return (readcpio(name, asb)); } asb->sb_link[asb->sb_size] = '\0'; asb->sb_size = 0; } #endif /* S_IFLNK */ /* destroy absolute pathnames for security reasons */ if (name[0] == '/') { if (name[1]) { while (name[0] = name[1]) { ++name; } } else { name[0] = '.'; } } asb->sb_atime = asb->sb_ctime = asb->sb_mtime; if (asb->sb_nlink > 1) { linkto(name, asb); } return (0); } /* inswab - read a reversed by order binary header * * DESCRIPTIONS * * Reads a byte-swapped CPIO binary archive header * * PARMAMETERS * * char *magic - magic number to match * char *name - name of the file which is stored in the header. * (modified and passed back to caller). * Stat *asb - stat block for the file (modified and passed back * to the caller). * * * RETURNS * * Returns the number of trailing alignment bytes to skip; -1 if * unsuccessful. * */ #ifdef __STDC__ static int inswab(char *magic, char *name, Stat *asb) #else static int inswab(magic, name, asb) char *magic; char *name; Stat *asb; #endif { ushort namesize; uint namefull; Binary binary; if (*((ushort *) magic) != SWAB(M_BINARY)) { return (-1); } memcpy((char *) &binary, magic + sizeof(ushort), M_STRLEN - sizeof(ushort)); if (buf_read((char *) &binary + M_STRLEN - sizeof(ushort), sizeof(binary) - (M_STRLEN - sizeof(ushort))) < 0) { warnarch("Corrupt swapped header", (OFFSET) sizeof(binary) - (M_STRLEN - sizeof(ushort))); return (-1); } asb->sb_dev = (dev_t) SWAB(binary.b_dev); asb->sb_ino = (ino_t) SWAB(binary.b_ino); asb->sb_mode = SWAB(binary.b_mode); asb->sb_uid = SWAB(binary.b_uid); asb->sb_gid = SWAB(binary.b_gid); asb->sb_nlink = SWAB(binary.b_nlink); #ifndef _POSIX_SOURCE asb->sb_rdev = (dev_t) SWAB(binary.b_rdev); #endif asb->sb_mtime = SWAB(binary.b_mtime[0]) << 16 | SWAB(binary.b_mtime[1]); asb->sb_size = SWAB(binary.b_size[0]) << 16 | SWAB(binary.b_size[1]); if ((namesize = SWAB(binary.b_name)) == 0 || namesize >= PATH_MAX) { warnarch("Bad swapped pathname length", (OFFSET) sizeof(binary) - (M_STRLEN - sizeof(ushort))); return (-1); } if (buf_read(name, namefull = namesize + namesize % 2) < 0) { warnarch("Corrupt swapped pathname", (OFFSET) namefull); return (-1); } if (name[namesize - 1] != '\0') { warnarch("Bad swapped pathname", (OFFSET) namefull); return (-1); } return (asb->sb_size % 2); } /* inascii - read in an ASCII cpio header * * DESCRIPTION * * Reads an ASCII format cpio header * * PARAMETERS * * char *magic - magic number to match * char *name - name of the file which is stored in the header. * (modified and passed back to caller). * Stat *asb - stat block for the file (modified and passed back * to the caller). * * RETURNS * * Returns zero if successful; -1 otherwise. Assumes that the entire * magic number has been read. */ #ifdef __STDC__ static int inascii(char *magic, char *name, Stat *asb) #else static int inascii(magic, name, asb) char *magic; char *name; Stat *asb; #endif { uint namelen; char header[H_STRLEN + 1]; #ifdef _POSIX_SOURCE dev_t dummyrdev; #endif if (strncmp(magic, M_ASCII, M_STRLEN) != 0) { return (-1); } if (buf_read(header, H_STRLEN) < 0) { warnarch("Corrupt ASCII header", (OFFSET) H_STRLEN); return (-1); } header[H_STRLEN] = '\0'; if (sscanf(header, H_SCAN, &asb->sb_dev, &asb->sb_ino, &asb->sb_mode, &asb->sb_uid, #ifdef _POSIX_SOURCE &asb->sb_gid, &asb->sb_nlink, &dummyrdev, #else &asb->sb_gid, &asb->sb_nlink, &asb->sb_rdev, #endif &asb->sb_mtime, &namelen, &asb->sb_size) != H_COUNT) { warnarch("Bad ASCII header", (OFFSET) H_STRLEN); return (-1); } if (namelen == 0 || namelen >= PATH_MAX) { warnarch("Bad ASCII pathname length", (OFFSET) H_STRLEN); return (-1); } if (buf_read(name, namelen) < 0) { warnarch("Corrupt ASCII pathname", (OFFSET) namelen); return (-1); } if (name[namelen - 1] != '\0') { warnarch("Bad ASCII pathname", (OFFSET) namelen); return (-1); } return (0); } /* inbinary - read a binary header * * DESCRIPTION * * Reads a CPIO format binary header. * * PARAMETERS * * char *magic - magic number to match * char *name - name of the file which is stored in the header. * (modified and passed back to caller). * Stat *asb - stat block for the file (modified and passed back * to the caller). * * RETURNS * * Returns the number of trailing alignment bytes to skip; -1 if * unsuccessful. */ #ifdef __STDC__ static int inbinary(char *magic, char *name, Stat *asb) #else static int inbinary(magic, name, asb) char *magic; char *name; Stat *asb; #endif { uint namefull; Binary binary; if (*((ushort *) magic) != M_BINARY) { return (-1); } memcpy((char *) &binary, magic + sizeof(ushort), M_STRLEN - sizeof(ushort)); if (buf_read((char *) &binary + M_STRLEN - sizeof(ushort), sizeof(binary) - (M_STRLEN - sizeof(ushort))) < 0) { warnarch("Corrupt binary header", (OFFSET) sizeof(binary) - (M_STRLEN - sizeof(ushort))); return (-1); } asb->sb_dev = binary.b_dev; asb->sb_ino = binary.b_ino; asb->sb_mode = binary.b_mode; asb->sb_uid = binary.b_uid; asb->sb_gid = binary.b_gid; asb->sb_nlink = binary.b_nlink; #ifndef _POSIX_SOURCE asb->sb_rdev = binary.b_rdev; #endif asb->sb_mtime = binary.b_mtime[0] << 16 | binary.b_mtime[1]; asb->sb_size = binary.b_size[0] << 16 | binary.b_size[1]; if (binary.b_name == 0 || binary.b_name >= PATH_MAX) { warnarch("Bad binary pathname length", (OFFSET) sizeof(binary) - (M_STRLEN - sizeof(ushort))); return (-1); } if (buf_read(name, namefull = binary.b_name + binary.b_name % 2) < 0) { warnarch("Corrupt binary pathname", (OFFSET) namefull); return (-1); } if (name[binary.b_name - 1] != '\0') { warnarch("Bad binary pathname", (OFFSET) namefull); return (-1); } return (asb->sb_size % 2); }