tests: dynamically replace dnsmasq path

The path to the dnsmasq binary can be configured while in the test data
the path is hard-coded to /usr/bin/. This break the test suite if a the
binary is located in a different location, like /usr/local/sbin/.

Replace the hard coded path in the test data by a token, which is
dynamically replaced in networkxml2argvtest with the configured path
after the test data has been loaded.

(Another option would have been to modify configure.ac to generate the
 test data during configure, but I do not know of an easy way do trick
 configure into mass-generate those test files without listing every
 single one, which I consider less flexible.)

- unit-test the unit-test:
  #include <assert.h>
  #define TEST(in,token,rep,out) { char *buf = strdup(in); assert(!replaceTokens(&buf, token, rep) && !strcmp(buf, out)); free(buf); }
  TEST("", "AA", "B", "");
  TEST("A", "AA", "B", "A");
  TEST("AA", "AA", "B", "B");
  TEST("AAA", "AA", "B", "BA");
  TEST("AA", "AA", "BB", "BB");
  TEST("AA", "AA", "BBB", "BBB");
  TEST("<AA", "AA", "B", "<B");
  TEST("<AA", "AA", "BB", "<BB");
  TEST("<AA", "AA", "BBB", "<BBB");
  TEST("AA>", "AA", "B", "B>");
  TEST("AA>", "AA", "BB", "BB>");
  TEST("AA>", "AA", "BBB", "BBB>");
  TEST("<AA>", "AA", "B", "<B>");
  TEST("<AA>", "AA", "BB", "<BB>");
  TEST("<AA>", "AA", "BBB", "<BBB>");
  TEST("<AA|AA>", "AA", "B", "<B|B>");
  TEST("<AA|AA>", "AA", "BB", "<BB|BB>");
  TEST("<AA|AA>", "AA", "BBB", "<BBB|BBB>");
  TEST("<AAAA>", "AA", "B", "<BB>");
  TEST("<AAAA>", "AA", "BB", "<BBBB>");
  TEST("<AAAA>", "AA", "BBB", "<BBBBBB>");
  TEST("AAAA>", "AA", "B", "BB>");
  TEST("AAAA>", "AA", "BB", "BBBB>");
  TEST("AAAA>", "AA", "BBB", "BBBBBB>");
  TEST("<AAAA", "AA", "B", "<BB");
  TEST("<AAAA", "AA", "BB", "<BBBB");
  TEST("<AAAA", "AA", "BBB", "<BBBBBB");
  alarm(1); /* no infinite loop */
  TEST("A", "A", "A", "A");
  TEST("AA", "A", "A", "AA");
  alarm(0);

Signed-off-by: Philipp Hahn <hahn@univention.de>

tests/networkxml2argvdata/isolated-network.argv

@@ -1,4 +1,4 @@
-/usr/sbin/dnsmasq --strict-order --bind-interfaces --conf-file= \
+@DNSMASQ@ --strict-order --bind-interfaces --conf-file= \
 --except-interface lo --dhcp-option=3 --no-resolv \
 --listen-address 192.168.152.1 \
 --dhcp-range 192.168.152.2,192.168.152.254 \

tests/networkxml2argvdata/nat-network-dns-hosts.argv

@@ -1,3 +1,3 @@
-/usr/sbin/dnsmasq --strict-order --bind-interfaces --domain example.com \
+@DNSMASQ@ --strict-order --bind-interfaces --domain example.com \
 --conf-file= --except-interface lo --listen-address 192.168.122.1 \
 --expand-hosts --addn-hosts=/var/lib/libvirt/dnsmasq/default.addnhosts\

tests/networkxml2argvdata/nat-network-dns-srv-record-minimal.argv

@@ -1,4 +1,4 @@
-/usr/sbin/dnsmasq \
+@DNSMASQ@ \
 --strict-order \
 --bind-interfaces \
 --conf-file= \

tests/networkxml2argvdata/nat-network-dns-srv-record.argv

@@ -1,4 +1,4 @@
-/usr/sbin/dnsmasq \
+@DNSMASQ@ \
 --strict-order \
 --bind-interfaces \
 --conf-file= \

tests/networkxml2argvdata/nat-network-dns-txt-record.argv

@@ -1,4 +1,4 @@
-/usr/sbin/dnsmasq --strict-order --bind-interfaces --conf-file= \
+@DNSMASQ@ --strict-order --bind-interfaces --conf-file= \
 --except-interface lo --txt-record=example,example value \
 --listen-address 192.168.122.1 --listen-address 192.168.123.1 \
 --listen-address 2001:db8:ac10:fe01::1 \

tests/networkxml2argvdata/nat-network.argv

@@ -1,4 +1,4 @@
-/usr/sbin/dnsmasq --strict-order --bind-interfaces --conf-file= \
+@DNSMASQ@ --strict-order --bind-interfaces --conf-file= \
 --except-interface lo --listen-address 192.168.122.1 \
 --listen-address 192.168.123.1 --listen-address 2001:db8:ac10:fe01::1 \
 --listen-address 2001:db8:ac10:fd01::1 --listen-address 10.24.10.1 \

tests/networkxml2argvdata/netboot-network.argv

@@ -1,4 +1,4 @@
-/usr/sbin/dnsmasq --strict-order --bind-interfaces --domain example.com \
+@DNSMASQ@ --strict-order --bind-interfaces --domain example.com \
 --conf-file= --except-interface lo --listen-address 192.168.122.1 \
 --dhcp-range 192.168.122.2,192.168.122.254 \
 --dhcp-leasefile=/var/lib/libvirt/dnsmasq/netboot.leases \

tests/networkxml2argvdata/netboot-proxy-network.argv

@@ -1,4 +1,4 @@
-/usr/sbin/dnsmasq --strict-order --bind-interfaces --domain example.com \
+@DNSMASQ@ --strict-order --bind-interfaces --domain example.com \
 --conf-file= --except-interface lo --listen-address 192.168.122.1 \
 --dhcp-range 192.168.122.2,192.168.122.254 \
 --dhcp-leasefile=/var/lib/libvirt/dnsmasq/netboot.leases \

tests/networkxml2argvdata/routed-network.argv

@@ -1,2 +1,2 @@
-/usr/sbin/dnsmasq --strict-order --bind-interfaces --conf-file= \
+@DNSMASQ@ --strict-order --bind-interfaces --conf-file= \
 --except-interface lo --listen-address 192.168.122.1\

tests/networkxml2argvtest.c

@@ -15,6 +15,36 @@
 #include "memory.h"
 #include "network/bridge_driver.h"
 
+/* Replace all occurrences of @token in @buf by @replacement and adjust size of
+ * @buf accordingly. Returns 0 on success and -1 on out-of-memory errors. */
+static int replaceTokens(char **buf, const char *token, const char *replacement) {
+    char *token_start, *token_end;
+    size_t buf_len, rest_len;
+    const size_t token_len = strlen(token);
+    const size_t replacement_len = strlen(replacement);
+    const int diff = replacement_len - token_len;
+
+    buf_len = rest_len = strlen(*buf) + 1;
+    token_end = *buf;
+    for (;;) {
+        token_start = strstr(token_end, token);
+        if (token_start == NULL)
+            break;
+        rest_len -= token_start + token_len - token_end;
+        token_end = token_start + token_len;
+        buf_len += diff;
+        if (diff > 0)
+            if (VIR_REALLOC_N(*buf, buf_len) < 0)
+                return -1;
+        if (diff != 0)
+            memmove(token_end + diff, token_end, rest_len);
+        memcpy(token_start, replacement, replacement_len);
+        token_end += diff;
+    }
+    /* if diff < 0, we could shrink the buffer here... */
+    return 0;
+}
+
 static int testCompareXMLToArgvFiles(const char *inxml, const char *outargv) {
     char *inXmlData = NULL;
     char *outArgvData = NULL;
@@ -32,6 +62,9 @@ static int testCompareXMLToArgvFiles(const char *inxml, const char *outargv) {
     if (virtTestLoadFile(outargv, &outArgvData) < 0)
         goto fail;
 
+    if (replaceTokens(&outArgvData, "@DNSMASQ@", DNSMASQ))
+        goto fail;
+
     if (!(dev = virNetworkDefParseString(inXmlData)))
         goto fail;