[Qemu-devel] [PATCH 2/2] pci: rewrite devaddr parsing

[Michael S. Tsirkin]

Use scanf instead of manual string scanning.

Signed-off-by: Michael S. Tsirkin <address@hidden>
---
 hw/pci.c |   81 +++++++++++++++++++++++++++++---------------------------------
 1 files changed, 38 insertions(+), 43 deletions(-)

diff --git a/hw/pci.c b/hw/pci.c
index 5827c0e..a8c0b69 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -479,61 +479,56 @@ static void pci_set_default_subsystem_id(PCIDevice 
*pci_dev)
  *       [[<domain>:]<bus>:]<slot>.<func>, return -1 on error
  */
 static int pci_parse_devaddr(const char *addr, int *domp, int *busp,
-                      unsigned int *slotp, unsigned int *funcp)
-{
-    const char *p;
-    char *e;
-    unsigned long val;
-    unsigned long dom = 0, bus = 0;
-    unsigned int slot = 0;
-    unsigned int func = 0;
-
-    p = addr;
-    val = strtoul(p, &e, 16);
-    if (e == p)
-       return -1;
-    if (*e == ':') {
-       bus = val;
-       p = e + 1;
-       val = strtoul(p, &e, 16);
-       if (e == p)
-           return -1;
-       if (*e == ':') {
-           dom = bus;
-           bus = val;
-           p = e + 1;
-           val = strtoul(p, &e, 16);
-           if (e == p)
-               return -1;
-       }
-    }
-
-    slot = val;
-
-    if (funcp != NULL) {
-        if (*e != '.')
-            return -1;
+                             unsigned int *slotp, unsigned int *funcp)
+{
+    unsigned dom, bus, slot, func;
+    int n = -1;
+
+    /* Parse [[<domain>:]<bus>:]<slot> */
+    sscanf(addr, "%x:%x:%x%n", &dom, &bus, &slot, &n);
+    if (n == -1) {
+        dom = 0;
+        sscanf(addr, "%x:%x%n", &bus, &slot, &n);
+        if (n == -1) {
+            bus = 0;
+            sscanf(addr, "%x%n", &slot, &n);
+            if (n == -1) {
+                return -1;
+            }
+        }
+    }
 
-        p = e + 1;
-        val = strtoul(p, &e, 16);
-        if (e == p)
+    /* Parse the optional .func */
+    addr += n;
+    if (!*addr) {
+        func = 0;
+    } else {
+        sscanf(addr, ".%x%n", &func, &n);
+        if (n == -1) {
             return -1;
+        }
+        addr += n;
+    }
 
-        func = val;
+    /* Anything left? Malformed input. */
+    if (*addr) {
+        return -1;
     }
 
-    /* if funcp == NULL func is 0 */
-    if (dom > 0xffff || bus > 0xff || slot > 0x1f || func > 7)
-       return -1;
+    if (funcp == NULL) {
+        func = 0;
+    }
 
-    if (*e)
+    if (dom > 0xffff || bus > 0xff || slot > 0x1f || func > 7) {
        return -1;
+    }
 
     *domp = dom;
     *busp = bus;
     *slotp = slot;
-    if (funcp != NULL)
+    if (funcp != NULL) {
         *funcp = func;
+    }
     return 0;
 }
 
-- 
1.7.9.111.gf3fb0