tree-wide: be more careful with the type of array sizes

Previously we were a bit sloppy with the index and size types of arrays,
we'd regularly use unsigned. While I don't think this ever resulted in
real issues I think we should be more careful there and follow a
stricter regime: unless there's a strong reason not to use size_t for
array sizes and indexes, size_t it should be. Any allocations we do
ultimately will use size_t anyway, and converting forth and back between
unsigned and size_t will always be a source of problems.

Note that on 32bit machines "unsigned" and "size_t" are equivalent, and
on 64bit machines our arrays shouldn't grow that large anyway, and if
they do we have a problem, however that kind of overly large allocation
we have protections for usually, but for overflows we do not have that
so much, hence let's add it.

So yeah, it's a story of the current code being already "good enough",
but I think some extra type hygiene is better.

This patch tries to be comprehensive, but it probably isn't and I missed
a few cases. But I guess we can cover that later as we notice it. Among
smaller fixes, this changes:

1. strv_length()' return type becomes size_t

2. the unit file changes array size becomes size_t

3. DNS answer and query array sizes become size_t

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=76745

1 files changed, 5 insertions, 5 deletions

diff --git a/src/libsystemd/sd-bus/bus-message.c b/src/libsystemd/sd-bus/bus-message.c
index 3f4a2ba2b..61df50e43 100644
--- a/src/libsystemd/sd-bus/bus-message.c
+++ b/src/libsystemd/sd-bus/bus-message.c
@@ -399,7 +399,7 @@ int bus_message_from_header(
                 size_t footer_accessible,
                 size_t message_size,
                 int *fds,
-                unsigned n_fds,
+                size_t n_fds,
                 const char *label,
                 size_t extra,
                 sd_bus_message **ret) {
@@ -510,7 +510,7 @@ int bus_message_from_malloc(
                 void *buffer,
                 size_t length,
                 int *fds,
-                unsigned n_fds,
+                size_t n_fds,
                 const char *label,
                 sd_bus_message **ret) {
 
@@ -1651,7 +1651,7 @@ _public_ int sd_bus_message_append_string_space(
 _public_ int sd_bus_message_append_string_iovec(
                 sd_bus_message *m,
                 const struct iovec *iov,
-                unsigned n) {
+                unsigned n /* should be size_t, but is API now… 😞 */) {
 
         size_t size;
         unsigned i;
@@ -2575,7 +2575,7 @@ _public_ int sd_bus_message_append_array_iovec(
                 sd_bus_message *m,
                 char type,
                 const struct iovec *iov,
-                unsigned n) {
+                unsigned n /* should be size_t, but is API now… 😞 */) {
 
         size_t size;
         unsigned i;
@@ -5485,7 +5485,7 @@ _public_ int sd_bus_message_set_sender(sd_bus_message *m, const char *sender) {
 int bus_message_get_blob(sd_bus_message *m, void **buffer, size_t *sz) {
         size_t total;
         void *p, *e;
-        unsigned i;
+        size_t i;
         struct bus_body_part *part;
 
         assert(m);