core: clean up some confusing regarding SI decimal and IEC binary suffixes for sizes

According to Wikipedia it is customary to specify hardware metrics and
transfer speeds to the basis 1000 (SI decimal), while software metrics
and physical volatile memory (RAM) sizes to the basis 1024 (IEC binary).
So far we specified everything in IEC, let's fix that and be more
true to what's otherwise customary. Since we don't want to parse "Mi"
instead of "M" we document each time what the context used is.

4 files changed, 86 insertions, 19 deletions

diff --git a/src/shared/conf-parser.c b/src/shared/conf-parser.c
index dde62b5755..cfa669b113 100644
--- a/src/shared/conf-parser.c
+++ b/src/shared/conf-parser.c
@@ -447,8 +447,7 @@ DEFINE_PARSER(double, double, safe_atod)
 DEFINE_PARSER(nsec, nsec_t, parse_nsec)
 DEFINE_PARSER(sec, usec_t, parse_sec)
 
-
-int config_parse_bytes_size(const char* unit,
+int config_parse_iec_size(const char* unit,
                             const char *filename,
                             unsigned line,
                             const char *section,
@@ -468,10 +467,9 @@ int config_parse_bytes_size(const char* unit,
         assert(rvalue);
         assert(data);
 
-        r = parse_bytes(rvalue, &o);
+        r = parse_size(rvalue, 1024, &o);
         if (r < 0 || (off_t) (size_t) o != o) {
-                log_syntax(unit, LOG_ERR, filename, line, -r,
-                           "Failed to parse byte value, ignoring: %s", rvalue);
+                log_syntax(unit, LOG_ERR, filename, line, r < 0 ? -r : ERANGE, "Failed to parse size value, ignoring: %s", rvalue);
                 return 0;
         }
 
@@ -479,8 +477,37 @@ int config_parse_bytes_size(const char* unit,
         return 0;
 }
 
+int config_parse_si_size(const char* unit,
+                            const char *filename,
+                            unsigned line,
+                            const char *section,
+                            unsigned section_line,
+                            const char *lvalue,
+                            int ltype,
+                            const char *rvalue,
+                            void *data,
+                            void *userdata) {
+
+        size_t *sz = data;
+        off_t o;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        r = parse_size(rvalue, 1000, &o);
+        if (r < 0 || (off_t) (size_t) o != o) {
+                log_syntax(unit, LOG_ERR, filename, line, r < 0 ? -r : ERANGE, "Failed to parse size value, ignoring: %s", rvalue);
+                return 0;
+        }
+
+        *sz = (size_t) o;
+        return 0;
+}
 
-int config_parse_bytes_off(const char* unit,
+int config_parse_iec_off(const char* unit,
                            const char *filename,
                            unsigned line,
                            const char *section,
@@ -501,10 +528,9 @@ int config_parse_bytes_off(const char* unit,
 
         assert_cc(sizeof(off_t) == sizeof(uint64_t));
 
-        r = parse_bytes(rvalue, bytes);
+        r = parse_size(rvalue, 1024, bytes);
         if (r < 0)
-                log_syntax(unit, LOG_ERR, filename, line, -r,
-                           "Failed to parse bytes value, ignoring: %s", rvalue);
+                log_syntax(unit, LOG_ERR, filename, line, -r, "Failed to parse size value, ignoring: %s", rvalue);
 
         return 0;
 }
diff --git a/src/shared/conf-parser.h b/src/shared/conf-parser.h
index ebbcaa54fe..4ccdaddd29 100644
--- a/src/shared/conf-parser.h
+++ b/src/shared/conf-parser.h
@@ -97,8 +97,9 @@ int config_parse_unsigned(const char *unit, const char *filename, unsigned line,
 int config_parse_long(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_uint64(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_double(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line,  const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
-int config_parse_bytes_size(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
-int config_parse_bytes_off(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_iec_size(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_si_size(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_iec_off(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_bool(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_show_status(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_string(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
diff --git a/src/shared/util.c b/src/shared/util.c
index b33f1203e6..5cb598c4c5 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -2135,11 +2135,28 @@ ssize_t loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
         return n;
 }
 
-int parse_bytes(const char *t, off_t *bytes) {
-        static const struct {
+int parse_size(const char *t, off_t base, off_t *size) {
+
+        /* Soo, sometimes we want to parse IEC binary suffxies, and
+         * sometimes SI decimal suffixes. This function can parse
+         * both. Which one is the right way depends on the
+         * context. Wikipedia suggests that SI is customary for
+         * hardrware metrics and network speeds, while IEC is
+         * customary for most data sizes used by software and volatile
+         * (RAM) memory. Hence be careful which one you pick!
+         *
+         * In either case we use just K, M, G as suffix, and not Ki,
+         * Mi, Gi or so (as IEC would suggest). That's because that's
+         * frickin' ugly. But this means you really need to make sure
+         * to document which base you are parsing when you use this
+         * call. */
+
+        struct table {
                 const char *suffix;
                 unsigned long long factor;
-        } table[] = {
+        };
+
+        static const struct table iec[] = {
                 { "B", 1 },
                 { "K", 1024ULL },
                 { "M", 1024ULL*1024ULL },
@@ -2150,11 +2167,33 @@ int parse_bytes(const char *t, off_t *bytes) {
                 { "", 1 },
         };
 
+        static const struct table si[] = {
+                { "B", 1 },
+                { "K", 1000ULL },
+                { "M", 1000ULL*1000ULL },
+                { "G", 1000ULL*1000ULL*1000ULL },
+                { "T", 1000ULL*1000ULL*1000ULL*1000ULL },
+                { "P", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
+                { "E", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
+                { "", 1 },
+        };
+
+        const struct table *table;
         const char *p;
         unsigned long long r = 0;
+        unsigned n_entries;
 
         assert(t);
-        assert(bytes);
+        assert(base == 1000 || base == 1024);
+        assert(size);
+
+        if (base == 1000) {
+                table = si;
+                n_entries = ELEMENTSOF(si);
+        } else {
+                table = iec;
+                n_entries = ELEMENTSOF(iec);
+        }
 
         p = t;
         do {
@@ -2176,7 +2215,7 @@ int parse_bytes(const char *t, off_t *bytes) {
 
                 e += strspn(e, WHITESPACE);
 
-                for (i = 0; i < ELEMENTSOF(table); i++)
+                for (i = 0; i < n_entries; i++)
                         if (startswith(e, table[i].suffix)) {
                                 unsigned long long tmp;
                                 if ((unsigned long long) l > ULLONG_MAX / table[i].factor)
@@ -2193,12 +2232,12 @@ int parse_bytes(const char *t, off_t *bytes) {
                                 break;
                         }
 
-                if (i >= ELEMENTSOF(table))
+                if (i >= n_entries)
                         return -EINVAL;
 
         } while (*p);
 
-        *bytes = r;
+        *size = r;
 
         return 0;
 }
diff --git a/src/shared/util.h b/src/shared/util.h
index d1230d2b64..9913fcefae 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -144,8 +144,9 @@ int close_nointr(int fd);
 void close_nointr_nofail(int fd);
 void close_many(const int fds[], unsigned n_fd);
 
+int parse_size(const char *t, off_t base, off_t *size);
+
 int parse_boolean(const char *v) _pure_;
-int parse_bytes(const char *t, off_t *bytes);
 int parse_pid(const char *s, pid_t* ret_pid);
 int parse_uid(const char *s, uid_t* ret_uid);
 #define parse_gid(s, ret_uid) parse_uid(s, ret_uid)