Calculating file checksums aint legacy activity

- move the checksumming into librpmio
- rename domd5() to rpmDoDigest() with future expansion for specifying
  digest algorithm type (ignored for now)
- rearrange parameters to leave return types last
- one less rpmio_internal outside rpmio/, whee...
- used all over the rpm tree, and it knows about handling prelinked files
  so potentially useful for outside users, might as well export it
- new public header rpmfilutil.h for collecting this sort of stuff

1 files changed, 221 insertions, 0 deletions

diff --git a/rpmio/rpmfileutil.c b/rpmio/rpmfileutil.c
new file mode 100644
index 000000000..e79a65ad3
--- /dev/null
+++ b/rpmio/rpmfileutil.c
@@ -0,0 +1,221 @@
+#include "system.h"
+
+#if HAVE_GELF_H
+
+#include <gelf.h>
+
+#if !defined(DT_GNU_PRELINKED)
+#define DT_GNU_PRELINKED        0x6ffffdf5
+#endif
+#if !defined(DT_GNU_LIBLIST)
+#define DT_GNU_LIBLIST          0x6ffffef9
+#endif
+
+#endif
+
+#include "rpmio_internal.h"
+#include <rpmfileutil.h>
+#include <rpmurl.h>
+#include <rpmmacro.h>
+#include <argv.h>
+
+static int open_dso(const char * path, pid_t * pidp, size_t *fsizep)
+{
+    static const char * cmd = NULL;
+    static int initted = 0;
+    int fdno;
+
+    if (!initted) {
+	cmd = rpmExpand("%{?__prelink_undo_cmd}", NULL);
+	initted++;
+    }
+
+    if (pidp) *pidp = 0;
+
+    if (fsizep) {
+	struct stat sb, * st = &sb;
+	if (stat(path, st) < 0)
+	    return -1;
+	*fsizep = st->st_size;
+    }
+
+    fdno = open(path, O_RDONLY);
+    if (fdno < 0)
+	return fdno;
+
+    if (!(cmd && *cmd))
+	return fdno;
+
+#if HAVE_GELF_H && HAVE_LIBELF
+ {  Elf *elf = NULL;
+    Elf_Scn *scn = NULL;
+    Elf_Data *data = NULL;
+    GElf_Ehdr ehdr;
+    GElf_Shdr shdr;
+    GElf_Dyn dyn;
+    int bingo;
+
+    (void) elf_version(EV_CURRENT);
+
+    if ((elf = elf_begin (fdno, ELF_C_READ, NULL)) == NULL
+     || elf_kind(elf) != ELF_K_ELF
+     || gelf_getehdr(elf, &ehdr) == NULL
+     || !(ehdr.e_type == ET_DYN || ehdr.e_type == ET_EXEC))
+	goto exit;
+
+    bingo = 0;
+    while (!bingo && (scn = elf_nextscn(elf, scn)) != NULL) {
+	(void) gelf_getshdr(scn, &shdr);
+	if (shdr.sh_type != SHT_DYNAMIC)
+	    continue;
+	while (!bingo && (data = elf_getdata (scn, data)) != NULL) {
+	    int maxndx = data->d_size / shdr.sh_entsize;
+	    int ndx;
+
+            for (ndx = 0; ndx < maxndx; ++ndx) {
+		(void) gelf_getdyn (data, ndx, &dyn);
+		if (!(dyn.d_tag == DT_GNU_PRELINKED || dyn.d_tag == DT_GNU_LIBLIST))
+		    continue;
+		bingo = 1;
+		break;
+	    }
+	}
+    }
+
+    if (pidp != NULL && bingo) {
+	int pipes[2];
+	pid_t pid;
+	int xx;
+
+	xx = close(fdno);
+	pipes[0] = pipes[1] = -1;
+	xx = pipe(pipes);
+	if (!(pid = fork())) {
+	    ARGV_t av, lib;
+	    argvSplit(&av, cmd, " ");
+
+	    xx = close(pipes[0]);
+	    xx = dup2(pipes[1], STDOUT_FILENO);
+	    xx = close(pipes[1]);
+	    if ((lib = argvSearch(av, "library", NULL)) != NULL) {
+		*lib = path;
+		unsetenv("MALLOC_CHECK_");
+		xx = execve(av[0], (char *const *)av+1, environ);
+	    }
+	    _exit(127);
+	}
+	*pidp = pid;
+	fdno = pipes[0];
+	xx = close(pipes[1]);
+    }
+
+exit:
+    if (elf) (void) elf_end(elf);
+ }
+#endif
+
+    return fdno;
+}
+
+int rpmDoDigest(pgpHashAlgo algo, const char * fn,int asAscii,
+                unsigned char * digest, size_t * fsizep)
+{
+    const char * path;
+    urltype ut = urlPath(fn, &path);
+    unsigned char * md5sum = NULL;
+    size_t md5len;
+    unsigned char buf[32*BUFSIZ];
+    FD_t fd;
+    size_t fsize = 0;
+    pid_t pid = 0;
+    int rc = 0;
+    int fdno;
+
+    fdno = open_dso(path, &pid, &fsize);
+    if (fdno < 0) {
+	rc = 1;
+	goto exit;
+    }
+
+    /* file to large (32 MB), do not mmap file */
+    if (fsize > (size_t) 32*1024*1024)
+      if (ut == URL_IS_PATH || ut == URL_IS_UNKNOWN)
+	ut = URL_IS_DASH; /* force fd io */
+
+    switch(ut) {
+    case URL_IS_PATH:
+    case URL_IS_UNKNOWN:
+#ifdef HAVE_MMAP
+      if (pid == 0) {
+	DIGEST_CTX ctx;
+	void * mapped;
+
+	if (fsize) {
+	    mapped = mmap(NULL, fsize, PROT_READ, MAP_SHARED, fdno, 0);
+	    if (mapped == (void *)-1) {
+		xx = close(fdno);
+		rc = 1;
+		break;
+	    }
+
+#ifdef	MADV_SEQUENTIAL
+	    xx = madvise(mapped, fsize, MADV_SEQUENTIAL);
+#endif
+	}
+
+	ctx = rpmDigestInit(PGPHASHALGO_MD5, RPMDIGEST_NONE);
+	if (fsize)
+	    xx = rpmDigestUpdate(ctx, mapped, fsize);
+	xx = rpmDigestFinal(ctx, (void **)&md5sum, &md5len, asAscii);
+	if (fsize)
+	    xx = munmap(mapped, fsize);
+	xx = close(fdno);
+	break;
+      }
+#endif
+    case URL_IS_HTTPS:
+    case URL_IS_HTTP:
+    case URL_IS_FTP:
+    case URL_IS_HKP:
+    case URL_IS_DASH:
+    default:
+	/* Either use the pipe to prelink -y or open the URL. */
+	fd = (pid != 0) ? fdDup(fdno) : Fopen(fn, "r.ufdio");
+	(void) close(fdno);
+	if (fd == NULL || Ferror(fd)) {
+	    rc = 1;
+	    if (fd != NULL)
+		(void) Fclose(fd);
+	    break;
+	}
+	
+	fdInitDigest(fd, PGPHASHALGO_MD5, 0);
+	fsize = 0;
+	while ((rc = Fread(buf, sizeof(buf[0]), sizeof(buf), fd)) > 0)
+	    fsize += rc;
+	fdFiniDigest(fd, PGPHASHALGO_MD5, (void **)&md5sum, &md5len, asAscii);
+	if (Ferror(fd))
+	    rc = 1;
+
+	(void) Fclose(fd);
+	break;
+    }
+
+    /* Reap the prelink -y helper. */
+    if (pid) {
+	int status;
+	(void) waitpid(pid, &status, 0);
+	if (!WIFEXITED(status) || WEXITSTATUS(status))
+	    rc = 1;
+    }
+
+exit:
+    if (fsizep)
+	*fsizep = fsize;
+    if (!rc)
+	memcpy(digest, md5sum, md5len);
+    md5sum = _free(md5sum);
+
+    return rc;
+}
+