Re: [Libguestfs] [PATCH 2/5] daemon: add a way to check for the version of augeas

Query augeas for its version when required, i.e. only once when using the new augeas_is_version function. --- daemon/augeas.c | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ daemon/daemon.h | 16 +++++++- 2 files changed, 131 insertions(+), 1 deletion(-) diff --git a/daemon/augeas.c b/daemon/augeas.c index 74f3ba7..8dc6a7c 100644 --- a/daemon/augeas.c +++ b/daemon/augeas.c @@ -24,10 +24,46 @@ #include <unistd.h> #include <augeas.h> +#include <pcre.h> #include "daemon.h" #include "actions.h" #include "optgroups.h" +#include "xstrtol.h" + +#ifdef HAVE_ATTRIBUTE_CLEANUP +#define CLEANUP_PCRE_FREE __attribute__((cleanup(cleanup_pcre_free))) + +static void +cleanup_pcre_free (void *ptr) +{ + pcre *re = * (pcre **) ptr; + + if (re != NULL) + pcre_free (re); +} + +#else +#define CLEANUP_PCRE_FREE +#endif + +#define FPRINTF_AUGEAS_ERROR(aug,fs,...) \ + do { \ + int code = aug_error (aug); \ + if (code == AUG_ENOMEM) \ + reply_with_error (fs ": augeas out of memory", ##__VA_ARGS__); \ + else { \ + const char *message = aug_error_message (aug); \ + const char *minor = aug_error_minor_message (aug); \ + const char *details = aug_error_details (aug); \ + fprintf (stderr, fs ": %s%s%s%s%s", ##__VA_ARGS__, \ + message, \ + minor ? ": " : "", minor ? minor : "", \ + details ? ": " : "", details ? details : ""); \ + } \ + } while (0) + +int augeas_version; /* The Augeas handle. We maintain a single handle per daemon, which * is all that is necessary and reduces the complexity of the API @@ -35,6 +71,86 @@ */ static augeas *aug = NULL; +void +aug_read_version (void) +{ + CLEANUP_AUG_CLOSE augeas *ah = NULL; + int r; + const char *str; + CLEANUP_PCRE_FREE pcre *re = NULL; + const char *errptr; + int erroffset; + size_t len; +#define N_MATCHES 4 + int vec[N_MATCHES * 4]; + unsigned long int major = 0, minor = 0, patch = 0; + + if (augeas_version != 0) + return; + + /* Optimization: do not load the files nor the lenses, since we are + * only interested in the version. + */ + ah = aug_init ("/", NULL, AUG_NO_ERR_CLOSE | AUG_NO_LOAD | AUG_NO_STDINC); + if (!ah) { + FPRINTF_AUGEAS_ERROR (ah, "augeas initialization failed"); + return; + } + + if (aug_error (ah) != AUG_NOERROR) { + FPRINTF_AUGEAS_ERROR (ah, "aug_init"); + return; + } + + r = aug_get (ah, "/augeas/version", &str); + if (r != 1) { + FPRINTF_AUGEAS_ERROR (ah, "aug_get"); + return; + }

+ re = pcre_compile ("(\\d+)\\.(\\d+)(\\.(\\d+))?", + 0, &errptr, &erroffset, NULL); + if (re == NULL) { + fprintf (stderr, "cannot compile the augeas version regexp\n"); + return; + } + + len = strlen (str); + r = pcre_exec (re, NULL, str, len, 0, 0, vec, sizeof (vec) / sizeof (vec[0])); + if (r == PCRE_ERROR_NOMATCH) { + fprintf (stderr, "cannot match the version string in '%s'\n", str); + return; + } + + if (r > 1) { + if (xstrtoul (&str[vec[2]], NULL, 10, &major, NULL) != LONGINT_OK) { + fprintf (stderr, "could not parse '%*s' as integer\n", + vec[3]-vec[2], &str[vec[2]]); + return; + } + } + if (r > 2) { + if (xstrtoul (&str[vec[4]], NULL, 10, &minor, NULL) != LONGINT_OK) { + fprintf (stderr, "could not parse '%*s' as integer\n", + vec[5]-vec[4], &str[vec[4]]); + return; + } + } + if (r > 4) { + if (xstrtoul (&str[vec[8]], NULL, 10, &patch, NULL) != LONGINT_OK) { + fprintf (stderr, "could not parse '%*s' as integer\n", + vec[9]-vec[8], &str[vec[8]]); + return; + } + } + + if (verbose) + fprintf (stderr, "augeas version: %ld.%ld.%ld\n", major, minor, patch); + + augeas_version = (int) ((major << 16) | (minor << 8) | patch); +#undef N_MATCHES +} + /* Clean up the augeas handle on daemon exit. */ void aug_finalize (void) __attribute__((destructor)); void diff --git a/daemon/daemon.h b/daemon/daemon.h index b9e7402..0ccbc9e 100644 --- a/daemon/daemon.h +++ b/daemon/daemon.h @@ -228,8 +228,22 @@ extern void copy_lvm (void); /*-- in zero.c --*/ extern void wipe_device_before_mkfs (const char *device); -/*-- in augeas.c, hivex.c, journal.c --*/ +/*-- in augeas.c --*/ +extern void aug_read_version (void); extern void aug_finalize (void); + +/* The version of augeas, saved as: + * (MAJOR << 16) | (MINOR << 8) | PATCH + */ +extern int augeas_version; +static inline int +augeas_is_version (int major, int minor, int patch) +{ + aug_read_version (); /* Lazy version reading. */ + return augeas_version >= ((major << 16) | (minor << 8) | patch); +} + +/*-- hivex.c, journal.c --*/ extern void hivex_finalize (void); extern void journal_finalize (void); -- 1.9.3 _______________________________________________ Libguestfs mailing list Libguestfs(a)redhat.com https://www.redhat.com/mailman/listinfo/libguestfs