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path: root/src/skaembutils/s6-update-symlinks.c
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Diffstat (limited to 'src/skaembutils/s6-update-symlinks.c')
-rw-r--r--src/skaembutils/s6-update-symlinks.c348
1 files changed, 0 insertions, 348 deletions
diff --git a/src/skaembutils/s6-update-symlinks.c b/src/skaembutils/s6-update-symlinks.c
deleted file mode 100644
index 6b9a145..0000000
--- a/src/skaembutils/s6-update-symlinks.c
+++ /dev/null
@@ -1,348 +0,0 @@
-/* ISC license. */
-
-#include <string.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <errno.h>
-#include <stdio.h>
-
-#include <skalibs/direntry.h>
-#include <skalibs/strerr.h>
-#include <skalibs/stralloc.h>
-#include <skalibs/djbunix.h>
-#include <skalibs/random.h>
-
-#define USAGE "s6-update-symlinks /destdir /srcdir [ /srcdir ... ]"
-
-#define UPDATESYMLINKS_MAGICNEW ":s6-update-symlinks-new"
-#define UPDATESYMLINKS_MAGICOLD ":s6-update-symlinks-old"
-
-#define CONFLICT -2
-#define ERROR -1
-#define MODIFIED 0
-#define OVERRIDEN 1
-
-typedef struct stralloc5 stralloc5, *stralloc5_ref ;
-struct stralloc5
-{
- stralloc dst ;
- stralloc src ;
- stralloc tmp ;
- stralloc errdst ;
- stralloc errsrc ;
-} ;
-
-#define STRALLOC5_ZERO { STRALLOC_ZERO, STRALLOC_ZERO, STRALLOC_ZERO, STRALLOC_ZERO, STRALLOC_ZERO }
-
-static void updatesymlinks_cleanup (stralloc *sa, unsigned int pos)
-{
- int e = errno ;
- rm_rf_in_tmp(sa, pos) ;
- errno = e ;
-}
-
-static int updatesymlinks_makeuniquename (stralloc *sa, char const *path, char const *magic)
-{
- size_t base = sa->len ;
- int wasnull = !sa->s ;
- if (!stralloc_cats(sa, path)) return 0 ;
- if (!stralloc_cats(sa, magic)) goto err ;
- if (!random_sauniquename(sa, 8)) goto err ;
- if (!stralloc_0(sa)) goto err ;
- return 1 ;
-
-err:
- if (wasnull) stralloc_free(sa) ; else sa->len = base ;
- return 0 ;
-}
-
-static int updatesymlinks_addlink (stralloc5 *blah, unsigned int dstpos, unsigned int srcpos)
-{
- if (symlink(blah->src.s + srcpos, blah->dst.s + dstpos) >= 0) return MODIFIED ;
- if (errno != EEXIST) return ERROR ;
-
- {
- size_t dstbase = blah->dst.len ;
- size_t srcbase = blah->src.len ;
- size_t tmpbase = blah->tmp.len ;
- size_t dststop ;
- size_t srcstop ;
- signed int diffsize = 0 ;
- int collect = 1 ;
-
- {
- size_t n = strlen(blah->dst.s + dstpos) ;
- if (!stralloc_readyplus(&blah->dst, n+1)) return ERROR ;
- stralloc_catb(&blah->dst, blah->dst.s + dstpos, n) ;
- }
- stralloc_catb(&blah->dst, "/", 1) ;
- dststop = blah->dst.len ;
-
- {
- int r ;
- DIR *dir = opendir(blah->dst.s + dstpos) ;
- if (!dir)
- {
- blah->dst.len = dstbase ;
- if (errno != ENOTDIR) return ERROR ;
- if ((unlink(blah->dst.s + dstpos) == -1)
- || (symlink(blah->src.s + srcpos, blah->dst.s + dstpos) == -1))
- return ERROR ;
- return OVERRIDEN ; /* replaced a link to a normal file */
- }
- r = sareadlink(&blah->src, blah->dst.s + dstpos) ;
- if ((r == -1) && (errno != EINVAL))
- {
- blah->dst.len = dstbase ;
- dir_close(dir) ;
- return ERROR ;
- }
- if (r < 0)
- {
- for (;;)
- {
- direntry *d ;
- errno = 0 ;
- d = readdir(dir) ;
- if (!d) break ;
- if ((d->d_name[0] == '.') && (!d->d_name[1] || ((d->d_name[1] == '.') && !d->d_name[2])))
- continue ;
- diffsize-- ; /* need to know the size for collect */
- }
- if (errno)
- {
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
- dir_close(dir) ;
- return ERROR ;
- }
- }
- else if ((unlink(blah->dst.s + dstpos) == -1)
- || (mkdir(blah->dst.s + dstpos, 0777) == -1)
- || !stralloc_catb(&blah->src, "/", 1))
- {
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
- dir_close(dir) ;
- return ERROR ;
- }
- else /* expand */
- {
- srcstop = blah->src.len ;
- for (;;)
- {
- direntry *d ;
- errno = 0 ;
- d = readdir(dir) ;
- if (!d) break ;
- if ((d->d_name[0] == '.') && (!d->d_name[1] || ((d->d_name[1] == '.') && !d->d_name[2])))
- continue ;
- diffsize-- ;
- blah->dst.len = dststop ;
- blah->src.len = srcstop ;
- if (!stralloc_cats(&blah->dst, d->d_name) || !stralloc_0(&blah->dst)
- || !stralloc_cats(&blah->src, d->d_name) || !stralloc_0(&blah->src)
- || (symlink(blah->src.s + srcbase, blah->dst.s + dstbase) == -1))
- {
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
- dir_close(dir) ;
- return ERROR ;
- }
- }
- if (errno)
- {
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
- dir_close(dir) ;
- return ERROR ;
- }
- }
- dir_close(dir) ;
- }
-
- blah->src.len = srcbase ;
- {
- size_t n = strlen(blah->src.s + srcpos) ;
- if (!stralloc_readyplus(&blah->src, n+1))
- {
- blah->dst.len = dstbase ;
- return ERROR ;
- }
- stralloc_catb(&blah->src, blah->src.s + srcpos, n) ;
- }
- stralloc_catb(&blah->src, "/", 1) ;
- srcstop = blah->src.len ;
-
-
- /* prepare tmp for recursion */
-
- {
- DIR *dir = opendir(blah->src.s + srcpos) ;
- if (!dir)
- {
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
- if (errno != ENOTDIR) return ERROR ;
- blah->errdst.len = blah->errsrc.len = 0 ;
- if (!stralloc_cats(&blah->errdst, blah->dst.s + dstpos) || !stralloc_0(&blah->errdst)
- || !stralloc_cats(&blah->errsrc, blah->src.s + srcpos) || !stralloc_0(&blah->errsrc))
- return ERROR ;
- return CONFLICT ; /* dst is a dir but src is not */
- }
- for (;;)
- {
- direntry *d ;
- errno = 0 ;
- d = readdir(dir) ;
- if (!d) break ;
- if ((d->d_name[0] == '.') && (!d->d_name[1] || ((d->d_name[1] == '.') && !d->d_name[2])))
- continue ;
- if (!stralloc_cats(&blah->tmp, d->d_name) || !stralloc_0(&blah->tmp))
- {
- blah->tmp.len = tmpbase ;
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
- dir_close(dir) ;
- return ERROR ;
- }
- }
- if (errno)
- {
- blah->tmp.len = tmpbase ;
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
- dir_close(dir) ;
- return ERROR ;
- }
- dir_close(dir) ;
- }
-
-
- /* recurse */
-
- {
- size_t i = tmpbase ;
- while (i < blah->tmp.len)
- {
- diffsize++ ;
- blah->dst.len = dststop ;
- blah->src.len = srcstop ;
- {
- size_t n = strlen(blah->tmp.s + i) + 1 ;
- if (!stralloc_catb(&blah->dst, blah->tmp.s + i, n)
- || !stralloc_catb(&blah->src, blah->tmp.s + i, n))
- {
- blah->tmp.len = tmpbase ;
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
- return ERROR ;
- }
- i += n ;
- }
- switch (updatesymlinks_addlink(blah, dstbase, srcbase))
- {
- case ERROR :
- blah->tmp.len = tmpbase ;
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
- return ERROR ;
- case CONFLICT :
- blah->tmp.len = tmpbase ;
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
- return CONFLICT ;
- case MODIFIED :
- collect = 0 ;
- }
- }
- }
- blah->tmp.len = tmpbase ;
- blah->src.len = srcbase ;
- blah->dst.len = dstbase ;
-
-
- /* collect */
-
- if (collect && !diffsize)
- {
- if (rm_rf_in_tmp(&blah->dst, dstpos) == -1) return ERROR ;
- if (symlink(blah->src.s + srcpos, blah->dst.s + dstpos) == -1) return ERROR ;
- return OVERRIDEN ;
- }
- }
- return MODIFIED ;
-}
-
-int main (int argc, char *const *argv)
-{
- stralloc5 blah = STRALLOC5_ZERO ;
- PROG = "s6-update-symlinks" ;
- if (argc < 3) strerr_dieusage(100, USAGE) ;
- {
- char *const *p = argv + 1 ;
- for (; *p ; p++) if (**p != '/') strerr_dieusage(100, USAGE) ;
- }
- {
- size_t i = strlen(argv[1]) ;
- while (i && (argv[1][i-1] == '/')) argv[1][--i] = 0 ;
- if (!i) strerr_diefu1x(100, "replace root directory") ;
- }
- if (!updatesymlinks_makeuniquename(&blah.dst, argv[1], UPDATESYMLINKS_MAGICNEW))
- strerr_diefu2sys(111, "make random unique name based on ", argv[1]) ;
- if ((unlink(blah.dst.s) == -1) && (errno != ENOENT))
- strerr_diefu2sys(111, "unlink ", blah.dst.s) ;
-
- {
- char *const *p = argv + 2 ;
- for (; *p ; p++)
- {
- int r ;
- blah.src.len = 0 ;
- if (!stralloc_cats(&blah.src, *p) || !stralloc_0(&blah.src))
- strerr_diefu1sys(111, "make stralloc") ;
- r = updatesymlinks_addlink(&blah, 0, 0) ;
- if (r < 0)
- {
- stralloc_free(&blah.tmp) ;
- stralloc_free(&blah.src) ;
- updatesymlinks_cleanup(&blah.dst, 0) ;
- stralloc_free(&blah.dst) ;
- if (r == CONFLICT)
- strerr_dief4x(100, "destination ", blah.errdst.s, " conflicts with source ", blah.errsrc.s) ;
- else
- strerr_dief2sys(111, "error processing ", *p) ;
- }
- }
- }
- stralloc_free(&blah.tmp) ;
-
- if (rename(blah.dst.s, argv[1]) == -1) /* be atomic if possible */
- {
- blah.src.len = 0 ;
- if (!updatesymlinks_makeuniquename(&blah.src, argv[1], UPDATESYMLINKS_MAGICOLD))
- {
- updatesymlinks_cleanup(&blah.dst, 0) ;
- strerr_diefu2sys(111, "make random unique name based on ", argv[1]) ;
- }
-
- if (rename(argv[1], blah.src.s) == -1)
- {
- updatesymlinks_cleanup(&blah.dst, 0) ;
- strerr_diefu4sys(111, "rename ", argv[1], " to ", blah.src.s) ;
- }
- /* XXX: unavoidable race condition here: argv[1] does not exist */
- if (rename(blah.dst.s, argv[1]) == -1)
- {
- rename(blah.src.s, argv[1]) ;
- updatesymlinks_cleanup(&blah.dst, 0) ;
- strerr_diefu4sys(111, "rename ", blah.dst.s, " to ", argv[1]) ;
- }
- stralloc_free(&blah.dst) ;
- if (rm_rf_in_tmp(&blah.src, 0) == -1)
- strerr_warnwu2sys("remove old directory ", blah.src.s) ;
- stralloc_free(&blah.src) ;
- }
-
- return 0 ;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-01 14:02:00 +0000