Replace config file parser for "xl"

This provides a replacement config file parser for "xl" based on bison
and flex.

Benefits:
  * proper error reporting with line numbers
  * parser can understand nearly all "xm" configuration files directly
     (doesn't understand Python code but should do everything else)
  * parser also understands the ;-infested "xl" style files
  * removes the dependency on libconfig
  * better checking for certain kinds of mistakes
  * eliminates the strange "massage file and try again" code

This is intended to support all config files currently supported by
"xl" and almost all files supported by "xm".  (NB that whether a
feature works depends on the implementation of that feature in
xl/libxl of course.)

This patch also introduces a new library "libxlutil" which is mainly
for the benefit of "xl".  Users of libxl do not need to use libxlutil,
but they can do so if they want to parse "xl" files without being
"xl".

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Vincent Hanquez <vincent.hanquez@eu.citrix.com>

1 files changed, 52 insertions, 111 deletions

diff --git a/tools/libxl/xl.c b/tools/libxl/xl.c
index 823c8177ec..6e88c6ee6a 100644
--- a/tools/libxl/xl.c
+++ b/tools/libxl/xl.c
@@ -19,7 +19,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <libconfig.h>
 #include <unistd.h>
 #include <sys/time.h> /* for time */
 #include <getopt.h>
@@ -34,6 +33,7 @@
 
 #include "libxl.h"
 #include "libxl_utils.h"
+#include "libxlutil.h"
 
 #define UUID_FMT "%02hhx%02hhx%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx-%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx"
 
@@ -320,63 +320,6 @@ static void printf_info(libxl_domain_create_info *c_info,
     }
 }
 
-static char* compat_config_file(const char *filename)
-{
-    char t;
-    char *newfile = (char*) malloc(strlen(filename) + 4);
-    char *buf = (char *) malloc(2048);
-    int size = 2048, i;
-    FILE *s;
-    FILE *d;
-
-    sprintf(newfile, "%s.xl", filename);
-
-    s = fopen(filename, "r");
-    if (!s) {
-        perror("cannot open file for reading");
-        return NULL;
-    }
-    d = fopen(newfile, "w");
-    if (!d) {
-        fclose(s);
-        perror("cannot open file for writting");
-        return NULL;
-    }
-
-    while (!feof(s)) {
-        buf[0] = 0;
-        fgets(buf, size, s);
-        while (buf[strlen(buf) - 1] != '\n' && !feof(s)) {
-            size += 1024;
-            buf = realloc(buf, size + 1024);
-            fgets(buf + (size - 1025), 1025, s);
-        }
-        for (i = 0; i < strlen(buf); i++)
-            if (buf[i] == '\'')
-                buf[i] = '\"';
-        if (strchr(buf, '=') != NULL) {
-            if ((buf[strlen(buf) - 1] == '\n' && buf[strlen(buf) - 2] == ';') ||
-                    buf[strlen(buf) - 1] == ';') {
-                fputs(buf, d);
-            } else {
-                t = buf[strlen(buf) - 1];
-                buf[strlen(buf) - 1] = ';';
-                fputs(buf, d);
-                fputc(t, d);
-            }
-        } else if (buf[0] == '#' || buf[0] == ' ' || buf[0] == '\n') {
-            fputs(buf, d);
-        }
-    }
-
-    fclose(s);
-    fclose(d);
-
-    free(buf);
-
-    return newfile;
-}
-
 static void parse_config_file(const char *filename,
                               libxl_domain_create_info *c_info,
                               libxl_domain_build_info *b_info,
@@ -394,35 +337,33 @@ static void parse_config_file(const char *filename,
 {
     const char *buf;
     long l;
-    struct config_t config;
-    struct config_setting_t *vbds, *nics, *pcis, *cvfbs;
+    XLU_Config *config;
+    XLU_ConfigList *vbds, *nics, *pcis, *cvfbs;
     int pci_power_mgmt = 0;
     int pci_msitranslate = 1;
-    int i;
+    int i, e;
 
-    config_init (&config);
+    config= xlu_cfg_init(stderr, filename);
+    if (!config) {
+        fprintf(stderr, "Failed to allocate for configuration\n");
+        exit(1);
+    }
 
-    if (!config_read_file(&config, filename)) {
-        char *newfilename;
-        config_destroy(&config);
-        newfilename = compat_config_file(filename);
-        config_init (&config);
-        if (!config_read_file(&config, newfilename)) {
-            fprintf(stderr, "Failed to parse config file %s on line %d, try removing any embedded python code\n", config_error_text(&config), config_error_line(&config));
-            exit(1);
-        }
-        free(newfilename);
+    e= xlu_cfg_readfile (config, filename);
+    if (e) {
+        fprintf(stderr, "Failed to parse config file: %s\n", strerror(e));
+        exit(1);
     }
 
     init_create_info(c_info);
 
     c_info->hvm = 0;
-    if ((config_lookup_string (&config, "builder", &buf) == CONFIG_TRUE) &&
+    if (!xlu_cfg_get_string (config, "builder", &buf) &&
         !strncmp(buf, "hvm", strlen(buf)))
         c_info->hvm = 1;
 
     /* hap is missing */
-    if (config_lookup_string (&config, "name", &buf) == CONFIG_TRUE)
+    if (!xlu_cfg_get_string (config, "name", &buf))
         c_info->name = strdup(buf);
     else
         c_info->name = "test";
@@ -433,48 +374,48 @@ static void parse_config_file(const char *filename,
     init_build_info(b_info, c_info);
 
     /* the following is the actual config parsing with overriding values in the structures */
-    if (config_lookup_int (&config, "vcpus", &l) == CONFIG_TRUE)
+    if (!xlu_cfg_get_long (config, "vcpus", &l))
         b_info->max_vcpus = l;
 
-    if (config_lookup_int (&config, "memory", &l) == CONFIG_TRUE) {
+    if (!xlu_cfg_get_long (config, "memory", &l)) {
         b_info->max_memkb = l * 1024;
         b_info->target_memkb = b_info->max_memkb;
     }
 
-    if (config_lookup_int (&config, "shadow_memory", &l) == CONFIG_TRUE)
+    if (!xlu_cfg_get_long (config, "shadow_memory", &l))
         b_info->shadow_memkb = l * 1024;
 
-    if (config_lookup_int (&config, "videoram", &l) == CONFIG_TRUE)
+    if (!xlu_cfg_get_long (config, "videoram", &l))
         b_info->video_memkb = l * 1024;
 
-    if (config_lookup_string (&config, "kernel", &buf) == CONFIG_TRUE)
+    if (!xlu_cfg_get_string (config, "kernel", &buf))
         b_info->kernel = strdup(buf);
 
     if (c_info->hvm == 1) {
-        if (config_lookup_int (&config, "pae", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "pae", &l))
             b_info->u.hvm.pae = l;
-        if (config_lookup_int (&config, "apic", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "apic", &l))
             b_info->u.hvm.apic = l;
-        if (config_lookup_int (&config, "acpi", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "acpi", &l))
             b_info->u.hvm.acpi = l;
-        if (config_lookup_int (&config, "nx", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "nx", &l))
             b_info->u.hvm.nx = l;
-        if (config_lookup_int (&config, "viridian", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "viridian", &l))
             b_info->u.hvm.viridian = l;
     } else {
         char *cmdline;
-        if (config_lookup_string (&config, "root", &buf) == CONFIG_TRUE) {
+        if (!xlu_cfg_get_string (config, "root", &buf)) {
             asprintf(&cmdline, "root=%s", buf);
             b_info->u.pv.cmdline = cmdline;
         }
-        if (config_lookup_string (&config, "ramdisk", &buf) == CONFIG_TRUE)
+        if (!xlu_cfg_get_string (config, "ramdisk", &buf))
             b_info->u.pv.ramdisk = strdup(buf);
     }
 
-    if ((vbds = config_lookup (&config, "disk")) != NULL) {
+    if (!xlu_cfg_get_list (config, "disk", &vbds, 0)) {
         *num_disks = 0;
         *disks = NULL;
-        while ((buf = config_setting_get_string_elem (vbds, *num_disks)) != NULL) {
+        while ((buf = xlu_cfg_get_listitem (vbds, *num_disks)) != NULL) {
             char *buf2 = strdup(buf);
             char *p, *p2;
             *disks = (libxl_device_disk *) realloc(*disks, sizeof (libxl_device_disk) * ((*num_disks) + 1));
@@ -530,10 +471,10 @@ static void parse_config_file(const char *filename,
         }
     }
 
-    if ((nics = config_lookup (&config, "vif")) != NULL) {
+    if (!xlu_cfg_get_list (config, "vif", &nics, 0)) {
         *num_vifs = 0;
         *vifs = NULL;
-        while ((buf = config_setting_get_string_elem (nics, *num_vifs)) != NULL) {
+        while ((buf = xlu_cfg_get_listitem (nics, *num_vifs)) != NULL) {
             char *buf2 = strdup(buf);
             char *p, *p2;
             *vifs = (libxl_device_nic *) realloc(*vifs, sizeof (libxl_device_nic) * ((*num_vifs) + 1));
@@ -593,12 +534,12 @@ skip:
         }
     }
 
-    if ((cvfbs = config_lookup (&config, "vfb")) != NULL) {
+    if (!xlu_cfg_get_list (config, "vfb", &cvfbs, 0)) {
         *num_vfbs = 0;
         *num_vkbs = 0;
         *vfbs = NULL;
         *vkbs = NULL;
-        while ((buf = config_setting_get_string_elem (cvfbs, *num_vfbs)) != NULL) {
+        while ((buf = xlu_cfg_get_listitem (cvfbs, *num_vfbs)) != NULL) {
             char *buf2 = strdup(buf);
             char *p, *p2;
             *vfbs = (libxl_device_vfb *) realloc(*vfbs, sizeof(libxl_device_vfb) * ((*num_vfbs) + 1));
@@ -643,16 +584,16 @@ skip_vfb:
         }
     }
 
-    if (config_lookup_int (&config, "pci_msitranslate", &l) == CONFIG_TRUE)
+    if (!xlu_cfg_get_long (config, "pci_msitranslate", &l))
         pci_msitranslate = l;
 
-    if (config_lookup_int (&config, "pci_power_mgmt", &l) == CONFIG_TRUE)
+    if (!xlu_cfg_get_long (config, "pci_power_mgmt", &l))
         pci_power_mgmt = l;
 
-    if ((pcis = config_lookup (&config, "pci")) != NULL) {
+    if (xlu_cfg_get_list (config, "pci", &pcis, 0)) {
         *num_pcidevs = 0;
         *pcidevs = NULL;
-        while ((buf = config_setting_get_string_elem (pcis, *num_pcidevs)) != NULL) {
+        while ((buf = xlu_cfg_get_listitem (pcis, *num_pcidevs)) != NULL) {
             unsigned int domain = 0, bus = 0, dev = 0, func = 0, vdevfn = 0;
             char *buf2 = strdup(buf);
             char *p;
@@ -690,37 +631,37 @@ skip_pci:
         init_dm_info(dm_info, c_info, b_info);
 
         /* then process config related to dm */
-        if (config_lookup_string (&config, "device_model", &buf) == CONFIG_TRUE)
+        if (!xlu_cfg_get_string (config, "device_model", &buf))
             dm_info->device_model = strdup(buf);
-        if (config_lookup_int (&config, "stdvga", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "stdvga", &l))
             dm_info->stdvga = l;
-        if (config_lookup_int (&config, "vnc", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "vnc", &l))
             dm_info->vnc = l;
-        if (config_lookup_string (&config, "vnclisten", &buf) == CONFIG_TRUE)
+        if (!xlu_cfg_get_string (config, "vnclisten", &buf))
             dm_info->vnclisten = strdup(buf);
-        if (config_lookup_int (&config, "vncdisplay", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "vncdisplay", &l))
             dm_info->vncdisplay = l;
-        if (config_lookup_int (&config, "vncunused", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "vncunused", &l))
             dm_info->vncunused = l;
-        if (config_lookup_string (&config, "keymap", &buf) == CONFIG_TRUE)
+        if (!xlu_cfg_get_string (config, "keymap", &buf))
             dm_info->keymap = strdup(buf);
-        if (config_lookup_int (&config, "sdl", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "sdl", &l))
             dm_info->sdl = l;
-        if (config_lookup_int (&config, "opengl", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "opengl", &l))
             dm_info->opengl = l;
-        if (config_lookup_int (&config, "nographic", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "nographic", &l))
             dm_info->nographic = l;
-        if (config_lookup_string (&config, "serial", &buf) == CONFIG_TRUE)
+        if (!xlu_cfg_get_string (config, "serial", &buf))
             dm_info->serial = strdup(buf);
-        if (config_lookup_string (&config, "boot", &buf) == CONFIG_TRUE)
+        if (!xlu_cfg_get_string (config, "boot", &buf))
             dm_info->boot = strdup(buf);
-        if (config_lookup_int (&config, "usb", &l) == CONFIG_TRUE)
+        if (!xlu_cfg_get_long (config, "usb", &l))
             dm_info->usb = l;
-        if (config_lookup_string (&config, "usbdevice", &buf) == CONFIG_TRUE)
+        if (!xlu_cfg_get_string (config, "usbdevice", &buf))
             dm_info->usbdevice = strdup(buf);
     }
 
-    config_destroy(&config);
+    xlu_cfg_destroy(config);
 }
 
 #define MUST( call ) ({                                                 \