xmalloc: Add and use xcalloc

Add a wrapper for calloc which checks for integer overflows in the
calculation of the size to allocate.

Use xcalloc to allocate an array of objects instead of calculating the
size ourselves, which might cause an integer overflow.

Signed-off-by: Tobias Klauser <[email protected]>

astraceroute.c

@@ -785,7 +785,7 @@ static int __process_time(struct ctx *ctx, int fd, int fd_cap, int ttl,
  return -EIO;
  }
 
- tmp = xmalloc(sizeof(struct timeval) * good);
+ tmp = xcalloc(good, sizeof(struct timeval));
  for (i = j = 0; i < array_size(probes); ++i) {
  if (probes[i].tv_sec == 0 && probes[i].tv_usec == 0)
  continue;

cpusched.c

@@ -140,7 +140,8 @@ static int cleanup_cpusched_batch(void *ptr)
 void init_cpusched(unsigned int cpus)
 {
  rwlock_init(&map_lock);
- cpu_work_map = xzmalloc((cpu_len = cpus) * sizeof(*cpu_work_map));
+ cpu_len = cpus;
+ cpu_work_map = xcalloc(cpu_len, sizeof(*cpu_work_map));
  init_hash(&mapper);
 }
 

curvetun_server.c

@@ -638,7 +638,7 @@ int server_main(char *home, char *dev, char *port, int udp, int ipv4, int log)
 
  set_nonblocking(lfd);
 
- events = xzmalloc(MAX_EPOLL_SIZE * sizeof(*events));
+ events = xcalloc(MAX_EPOLL_SIZE, sizeof(*events));
  for (i = 0; i < MAX_EPOLL_SIZE; ++i)
  events[i].data.fd = -1;
 
@@ -661,7 +661,7 @@ int server_main(char *home, char *dev, char *port, int udp, int ipv4, int log)
  if (!ispow2(threads))
  syslog_panic("Thread number not power of two!\n");
 
- threadpool = xzmalloc(sizeof(*threadpool) * threads);
+ threadpool = xcalloc(threads, sizeof(*threadpool));
  thread_spawn_or_panic(cpus, efd[1], refd[1], tunfd, ipv4, udp);
 
  init_cpusched(threads);

hash.c

@@ -94,7 +94,7 @@ static void grow_hash_table(struct hash_table *table)
  struct hash_table_entry *old_array = table->array, *new_array;
 
  new_size = alloc_nr(old_size);
- new_array = xzmalloc(sizeof(struct hash_table_entry) * new_size);
+ new_array = xcalloc(new_size, sizeof(struct hash_table_entry));
 
  table->size = new_size;
  table->array = new_array;

ifpps.c

@@ -173,7 +173,7 @@ static inline int padding_from_num(int n)
 }
 
 #define STATS_ALLOC1(member) \
- do { stats->member = xzmalloc(cpus * sizeof(*(stats->member))); } while (0)
+ do { stats->member = xcalloc(cpus, sizeof(*(stats->member))); } while (0)
 
 static void stats_alloc(struct ifstat *stats, unsigned int cpus)
 {
@@ -1425,7 +1425,7 @@ int main(int argc, char **argv)
  stats_alloc(&stats_new, cpus);
  stats_alloc(&stats_delta, cpus);
 
- cpu_hits = xzmalloc(cpus * sizeof(*cpu_hits));
+ cpu_hits = xcalloc(cpus, sizeof(*cpu_hits));
 
  if (promisc)
  ifflags = device_enter_promiscuous_mode(ifname);

xmalloc.c

@@ -34,6 +34,21 @@ void *xmalloc(size_t size)
  return ptr;
 }
 
+void *xcalloc(size_t nmemb, size_t size)
+{
+ void *ptr;
+
+ if (unlikely(nmemb == 0 || size == 0))
+ panic("xcalloc: zero size\n");
+
+ ptr = calloc(nmemb, size);
+ if (unlikely(ptr == NULL))
+ panic("xcalloc: out of memory (allocating %zu members of "
+ "%zu bytes)\n", nmemb, size);
+
+ return ptr;
+}
+
 void *xzmalloc(size_t size)
 {
  void *ptr = xmalloc(size);

xmalloc.h

@@ -7,6 +7,7 @@
 #include "die.h"
 
 extern void *xmalloc(size_t size) __hidden;
+extern void *xcalloc(size_t nmemb, size_t size) __hidden;
 extern void *xzmalloc(size_t size) __hidden;
 extern void *xmallocz(size_t size) __hidden;
 extern void *xmalloc_aligned(size_t size, size_t alignment) __hidden;