core: accept time units for time-based resource limits

Let's make sure "LimitCPU=30min" can be parsed properly, following the
usual logic how we parse time values. Similar for LimitRTTIME=.

While we are at it, extend a bit on the man page section about resource
limits.

Fixes: #1772

3 files changed, 105 insertions, 2 deletions

diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 5b7954dbf9..75388659e3 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -58,7 +58,7 @@ $1.RestrictAddressFamilies,      config_parse_address_families,      0,
 $1.SystemCallArchitectures,      config_parse_warn_compat,           DISABLED_CONFIGURATION,        0
 $1.SystemCallErrorNumber,        config_parse_warn_compat,           DISABLED_CONFIGURATION,        0
 $1.RestrictAddressFamilies,      config_parse_warn_compat,           DISABLED_CONFIGURATION,        0')
-$1.LimitCPU,                     config_parse_limit,                 RLIMIT_CPU,                    offsetof($1, exec_context.rlimit)
+$1.LimitCPU,                     config_parse_sec_limit,             RLIMIT_CPU,                    offsetof($1, exec_context.rlimit)
 $1.LimitFSIZE,                   config_parse_bytes_limit,           RLIMIT_FSIZE,                  offsetof($1, exec_context.rlimit)
 $1.LimitDATA,                    config_parse_bytes_limit,           RLIMIT_DATA,                   offsetof($1, exec_context.rlimit)
 $1.LimitSTACK,                   config_parse_bytes_limit,           RLIMIT_STACK,                  offsetof($1, exec_context.rlimit)
@@ -73,7 +73,7 @@ $1.LimitSIGPENDING,              config_parse_limit,                 RLIMIT_SIGP
 $1.LimitMSGQUEUE,                config_parse_bytes_limit,           RLIMIT_MSGQUEUE,               offsetof($1, exec_context.rlimit)
 $1.LimitNICE,                    config_parse_limit,                 RLIMIT_NICE,                   offsetof($1, exec_context.rlimit)
 $1.LimitRTPRIO,                  config_parse_limit,                 RLIMIT_RTPRIO,                 offsetof($1, exec_context.rlimit)
-$1.LimitRTTIME,                  config_parse_limit,                 RLIMIT_RTTIME,                 offsetof($1, exec_context.rlimit)
+$1.LimitRTTIME,                  config_parse_usec_limit,            RLIMIT_RTTIME,                 offsetof($1, exec_context.rlimit)
 $1.ReadWriteDirectories,         config_parse_namespace_path_strv,   0,                             offsetof($1, exec_context.read_write_dirs)
 $1.ReadOnlyDirectories,          config_parse_namespace_path_strv,   0,                             offsetof($1, exec_context.read_only_dirs)
 $1.InaccessibleDirectories,      config_parse_namespace_path_strv,   0,                             offsetof($1, exec_context.inaccessible_dirs)
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index cdc2ad950d..28b90eccc1 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -1136,6 +1136,107 @@ int config_parse_bytes_limit(
         return 0;
 }
 
+int config_parse_sec_limit(
+                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) {
+
+        struct rlimit **rl = data;
+        rlim_t seconds;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        rl += ltype;
+
+        if (streq(rvalue, "infinity"))
+                seconds = RLIM_INFINITY;
+        else {
+                usec_t t;
+
+                r = parse_sec(rvalue, &t);
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse resource value, ignoring: %s", rvalue);
+                        return 0;
+                }
+
+                if (t == USEC_INFINITY)
+                        seconds = RLIM_INFINITY;
+                else
+                        seconds = (rlim_t) (DIV_ROUND_UP(t, USEC_PER_SEC));
+        }
+
+        if (!*rl) {
+                *rl = new(struct rlimit, 1);
+                if (!*rl)
+                        return log_oom();
+        }
+
+        (*rl)->rlim_cur = (*rl)->rlim_max = seconds;
+        return 0;
+}
+
+
+int config_parse_usec_limit(
+                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) {
+
+        struct rlimit **rl = data;
+        rlim_t useconds;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        rl += ltype;
+
+        if (streq(rvalue, "infinity"))
+                useconds = RLIM_INFINITY;
+        else {
+                usec_t t;
+
+                r = parse_time(rvalue, &t, 1);
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse resource value, ignoring: %s", rvalue);
+                        return 0;
+                }
+
+                if (t == USEC_INFINITY)
+                        useconds = RLIM_INFINITY;
+                else
+                        useconds = (rlim_t) t;
+        }
+
+        if (!*rl) {
+                *rl = new(struct rlimit, 1);
+                if (!*rl)
+                        return log_oom();
+        }
+
+        (*rl)->rlim_cur = (*rl)->rlim_max = useconds;
+        return 0;
+}
+
 #ifdef HAVE_SYSV_COMPAT
 int config_parse_sysv_priority(const char *unit,
                                const char *filename,
diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
index 029775bb46..0cf821289c 100644
--- a/src/core/load-fragment.h
+++ b/src/core/load-fragment.h
@@ -57,6 +57,8 @@ int config_parse_exec_secure_bits(const char *unit, const char *filename, unsign
 int config_parse_bounding_set(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_limit(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_limit(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_sec_limit(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_usec_limit(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_sysv_priority(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_kill_signal(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_exec_mount_flags(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);