[Qemu-devel] [PATCH 1/4] Introduce strtosz() library function to convert a string to a byte count.

[Jes . Sorensen]

From: Jes Sorensen <address@hidden>

strtosz() returns -1 on error. It now supports human unit formats in
eg. 1.0G, with better error handling.

Signed-off-by: Jes Sorensen <address@hidden>
---
 cutils.c      |   61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-common.h |    1 +
 vl.c          |   31 +++++++++-------------------
 3 files changed, 72 insertions(+), 21 deletions(-)

diff --git a/cutils.c b/cutils.c
index 5883737..e5a135e 100644
--- a/cutils.c
+++ b/cutils.c
@@ -283,3 +283,64 @@ int fcntl_setfl(int fd, int flag)
 }
 #endif
 
+/*
+ * Convert string to bytes, allowing either K/k for KB, M/m for MB,
+ * G/g for GB or T/t for TB. Default without any postfix is MB.
+ * End pointer will be returned in *end, if end is valid.
+ * Return -1 on error.
+ */
+ssize_t strtosz(const char *nptr, char **end)
+{
+    ssize_t retval = -1;
+    int64_t tmpval;
+    char *endptr;
+    int mul_required = 0;
+    double val, mul = 1;
+
+    endptr = (char *)nptr + strspn(nptr, " 0123456789");
+    if (*endptr == '.') {
+        mul_required = 1;
+    }
+
+    errno = 0;
+    val = strtod(nptr, &endptr);
+    if (endptr == nptr || errno != 0 || val < 0)
+        goto fail;
+
+    switch (*endptr++) {
+    case 'K':
+    case 'k':
+        mul = 1 << 10;
+        break;
+    case 0:
+    case ' ':
+        if (mul_required) {
+            goto fail;
+        }
+    case 'M':
+    case 'm':
+        mul = 1ULL << 20;
+        break;
+    case 'G':
+    case 'g':
+        mul = 1ULL << 30;
+        break;
+    case 'T':
+    case 't':
+        mul = 1ULL << 40;
+        break;
+    default:
+        goto fail;
+    }
+
+    tmpval = (val * mul);
+    if (tmpval >= ~(size_t)0)
+        goto fail;
+    retval = tmpval;
+
+    if (end)
+        *end = endptr;
+
+fail:
+    return retval;
+}
diff --git a/qemu-common.h b/qemu-common.h
index 81aafa0..0a062d4 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -153,6 +153,7 @@ time_t mktimegm(struct tm *tm);
 int qemu_fls(int i);
 int qemu_fdatasync(int fd);
 int fcntl_setfl(int fd, int flag);
+ssize_t strtosz(const char *nptr, char **end);
 
 /* path.c */
 void init_paths(const char *prefix);
diff --git a/vl.c b/vl.c
index df414ef..6043fa2 100644
--- a/vl.c
+++ b/vl.c
@@ -734,16 +734,13 @@ static void numa_add(const char *optarg)
         if (get_param_value(option, 128, "mem", optarg) == 0) {
             node_mem[nodenr] = 0;
         } else {
-            value = strtoull(option, &endptr, 0);
-            switch (*endptr) {
-            case 0: case 'M': case 'm':
-                value <<= 20;
-                break;
-            case 'G': case 'g':
-                value <<= 30;
-                break;
+            ssize_t sval;
+            sval = strtosz(option, NULL);
+            if (sval < 0) {
+                fprintf(stderr, "qemu: invalid numa mem size: %s\n", optarg);
+                exit(1);
             }
-            node_mem[nodenr] = value;
+            node_mem[nodenr] = sval;
         }
         if (get_param_value(option, 128, "cpus", optarg) == 0) {
             node_cpumask[nodenr] = 0;
@@ -2163,18 +2160,10 @@ int main(int argc, char **argv, char **envp)
                 exit(0);
                 break;
             case QEMU_OPTION_m: {
-                uint64_t value;
-                char *ptr;
+                ssize_t value;
 
-                value = strtoul(optarg, &ptr, 10);
-                switch (*ptr) {
-                case 0: case 'M': case 'm':
-                    value <<= 20;
-                    break;
-                case 'G': case 'g':
-                    value <<= 30;
-                    break;
-                default:
+                value = strtosz(optarg, NULL);
+                if (value < 0) {
                     fprintf(stderr, "qemu: invalid ram size: %s\n", optarg);
                     exit(1);
                 }
-- 
1.7.2.3