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, 4 insertions, 4 deletions

diff --git a/src/resolve/resolved-dns-question.h b/src/resolve/resolved-dns-question.h
index fdedefe6c1..fcfa16f864 100644
--- a/src/resolve/resolved-dns-question.h
+++ b/src/resolve/resolved-dns-question.h
@@ -16,11 +16,11 @@ typedef struct DnsQuestion DnsQuestion;
 
 struct DnsQuestion {
         unsigned n_ref;
-        unsigned n_keys, n_allocated;
+        size_t n_keys, n_allocated;
         DnsResourceKey* keys[0];
 };
 
-DnsQuestion *dns_question_new(unsigned n);
+DnsQuestion *dns_question_new(size_t n);
 DnsQuestion *dns_question_ref(DnsQuestion *q);
 DnsQuestion *dns_question_unref(DnsQuestion *q);
 
@@ -40,7 +40,7 @@ int dns_question_cname_redirect(DnsQuestion *q, const DnsResourceRecord *cname,
 
 const char *dns_question_first_name(DnsQuestion *q);
 
-static inline unsigned dns_question_size(DnsQuestion *q) {
+static inline size_t dns_question_size(DnsQuestion *q) {
         return q ? q->n_keys : 0;
 }
 
@@ -51,7 +51,7 @@ static inline bool dns_question_isempty(DnsQuestion *q) {
 DEFINE_TRIVIAL_CLEANUP_FUNC(DnsQuestion*, dns_question_unref);
 
 #define _DNS_QUESTION_FOREACH(u, key, q)                                \
-        for (unsigned UNIQ_T(i, u) = ({                                 \
+        for (size_t UNIQ_T(i, u) = ({                                 \
                                 (key) = ((q) && (q)->n_keys > 0) ? (q)->keys[0] : NULL; \
                                 0;                                      \
                         });                                             \