ash,hush: fix ulimit to be more bash-compat, closes 11791

function                                             old     new   delta
shell_builtin_ulimit                                 486     651    +165
limit_chars                                            -      14     +14
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/0 up/down: 179/0)             Total: 179 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 181 insertions, 84 deletions

diff --git a/shell/shell_common.c b/shell/shell_common.c
index f2bf5ab65..686c18f54 100644
--- a/shell/shell_common.c
+++ b/shell/shell_common.c
@@ -335,62 +335,93 @@ shell_builtin_read(struct builtin_read_params *params)
 struct limits {
         uint8_t cmd;            /* RLIMIT_xxx fit into it */
         uint8_t factor_shift;   /* shift by to get rlim_{cur,max} values */
-        char option;
         const char *name;
 };
 
 static const struct limits limits_tbl[] = {
-#ifdef RLIMIT_FSIZE
-        { RLIMIT_FSIZE,         9,      'f',    "file size (blocks)" },
-#endif
+/* No RLIMIT_FSIZE define guard since -f is the default limit and this must exist */
+        { RLIMIT_FSIZE,         9,      "file size (blocks)" },      // -f
 #ifdef RLIMIT_CPU
-        { RLIMIT_CPU,           0,      't',    "cpu time (seconds)" },
+        { RLIMIT_CPU,           0,      "cpu time (seconds)" },      // -t
 #endif
 #ifdef RLIMIT_DATA
-        { RLIMIT_DATA,          10,     'd',    "data seg size (kb)" },
+        { RLIMIT_DATA,          10,     "data seg size (kb)" },      // -d
 #endif
 #ifdef RLIMIT_STACK
-        { RLIMIT_STACK,         10,     's',    "stack size (kb)" },
+        { RLIMIT_STACK,         10,     "stack size (kb)" },         // -s
 #endif
 #ifdef RLIMIT_CORE
-        { RLIMIT_CORE,          9,      'c',    "core file size (blocks)" },
+        { RLIMIT_CORE,          9,      "core file size (blocks)" }, // -c
 #endif
 #ifdef RLIMIT_RSS
-        { RLIMIT_RSS,           10,     'm',    "resident set size (kb)" },
+        { RLIMIT_RSS,           10,     "resident set size (kb)" },  // -m
 #endif
 #ifdef RLIMIT_MEMLOCK
-        { RLIMIT_MEMLOCK,       10,     'l',    "locked memory (kb)" },
+        { RLIMIT_MEMLOCK,       10,     "locked memory (kb)" },      // -l
 #endif
 #ifdef RLIMIT_NPROC
-        { RLIMIT_NPROC,         0,      'p',    "processes" },
+        { RLIMIT_NPROC,         0,      "processes" },               // -p
 #endif
 #ifdef RLIMIT_NOFILE
-        { RLIMIT_NOFILE,        0,      'n',    "file descriptors" },
+        { RLIMIT_NOFILE,        0,      "file descriptors" },        // -n
 #endif
 #ifdef RLIMIT_AS
-        { RLIMIT_AS,            10,     'v',    "address space (kb)" },
+        { RLIMIT_AS,            10,     "address space (kb)" },      // -v
 #endif
 #ifdef RLIMIT_LOCKS
-        { RLIMIT_LOCKS,         0,      'w',    "locks" },
+        { RLIMIT_LOCKS,         0,      "locks" },                   // -w
 #endif
 #ifdef RLIMIT_NICE
-        { RLIMIT_NICE,          0,      'e',    "scheduling priority" },
+        { RLIMIT_NICE,          0,      "scheduling priority" },     // -e
 #endif
 #ifdef RLIMIT_RTPRIO
-        { RLIMIT_RTPRIO,        0,      'r',    "real-time priority" },
+        { RLIMIT_RTPRIO,        0,      "real-time priority" },      // -r
 #endif
 };
 
-enum {
-        OPT_hard = (1 << 0),
-        OPT_soft = (1 << 1),
-};
+static const char limit_chars[] ALIGN1 =
+                        "f"
+#ifdef RLIMIT_CPU
+                        "t"
+#endif
+#ifdef RLIMIT_DATA
+                        "d"
+#endif
+#ifdef RLIMIT_STACK
+                        "s"
+#endif
+#ifdef RLIMIT_CORE
+                        "c"
+#endif
+#ifdef RLIMIT_RSS
+                        "m"
+#endif
+#ifdef RLIMIT_MEMLOCK
+                        "l"
+#endif
+#ifdef RLIMIT_NPROC
+                        "p"
+#endif
+#ifdef RLIMIT_NOFILE
+                        "n"
+#endif
+#ifdef RLIMIT_AS
+                        "v"
+#endif
+#ifdef RLIMIT_LOCKS
+                        "w"
+#endif
+#ifdef RLIMIT_NICE
+                        "e"
+#endif
+#ifdef RLIMIT_RTPRIO
+                        "r"
+#endif
+;
 
 /* "-": treat args as parameters of option with ASCII code 1 */
 static const char ulimit_opt_string[] ALIGN1 = "-HSa"
-#ifdef RLIMIT_FSIZE
                         "f::"
-#endif
 #ifdef RLIMIT_CPU
                         "t::"
 #endif
@@ -429,13 +460,19 @@ static const char ulimit_opt_string[] ALIGN1 = "-HSa"
 #endif
                         ;
 
+enum {
+        OPT_hard = (1 << 0),
+        OPT_soft = (1 << 1),
+        OPT_all  = (1 << 2),
+};
+
 static void printlim(unsigned opts, const struct rlimit *limit,
                         const struct limits *l)
 {
         rlim_t val;
 
         val = limit->rlim_max;
-        if (!(opts & OPT_hard))
+        if (opts & OPT_soft)
                 val = limit->rlim_cur;
 
         if (val == RLIM_INFINITY)
@@ -449,8 +486,11 @@ static void printlim(unsigned opts, const struct rlimit *limit,
 int FAST_FUNC
 shell_builtin_ulimit(char **argv)
 {
+        struct rlimit limit;
+        unsigned opt_cnt;
         unsigned opts;
         unsigned argc;
+        unsigned i;
 
         /* We can't use getopt32: need to handle commands like
          * ulimit 123 -c2 -l 456
@@ -461,12 +501,48 @@ shell_builtin_ulimit(char **argv)
          */
         GETOPT_RESET();
 
+// bash 4.4.23:
+//
+// -H and/or -S change meaning even of options *before* them: ulimit -f 2000 -H
+// sets hard limit, ulimit -a -H prints hard limits.
+//
+// -a is equivalent for requesting all limits to be shown.
+//
+// If -a is specified, attempts to set limits are ignored:
+//  ulimit -m 1000; ulimit -m 2000 -a
+// shows 1000, not 2000. HOWEVER, *implicit* -f form "ulimit 2000 -a"
+// DOES set -f limit [we don't implement this quirk], "ulimit -a 2000" does not.
+// Options are still parsed: ulimit -az complains about unknown -z opt.
+//
+// -a is not cumulative: "ulimit -a -a" = "ulimit -a -f -m" = "ulimit -a"
+//
+// -HSa can be combined in one argument and with one other option (example: -Sm),
+// but other options can't: limit value is an optional argument,
+// thus "-mf" means "-m f", f is the parameter of -m.
+//
+// Limit can be set and then printed: ulimit -m 2000 -m
+// If set more than once, they are set and printed in order:
+// try ulimit -m -m 1000 -m -m 2000 -m -m 3000 -m
+//
+// Limits are shown in the order of options given:
+// ulimit -m -f is not the same as ulimit -f -m.
+//
+// If both -S and -H are given, show soft limit.
+//
+// Short printout (limit value only) is printed only if just one option
+// is given: ulimit -m. ulimit -f -m prints verbose lines.
+// ulimit -f -f prints same verbose line twice.
+// ulimit -m 10000 -f prints verbose line for -f.
+
         argc = string_array_len(argv);
 
+        /* First pass over options: detect -H/-S/-a status,
+         * and "bare ulimit" and "only one option" cases
+         * by counting other opts.
+         */
+        opt_cnt = 0;
         opts = 0;
         while (1) {
-                struct rlimit limit;
-                const struct limits *l;
                 int opt_char = getopt(argc, argv, ulimit_opt_string);
 
                 if (opt_char == -1)
@@ -479,72 +555,93 @@ shell_builtin_ulimit(char **argv)
                         opts |= OPT_soft;
                         continue;
                 }
-
                 if (opt_char == 'a') {
-                        for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
-                                getrlimit(l->cmd, &limit);
-                                printf("-%c: %-30s ", l->option, l->name);
-                                printlim(opts, &limit, l);
-                        }
+                        opts |= OPT_all;
                         continue;
                 }
+                if (opt_char == '?') {
+                        /* bad option. getopt already complained. */
+                        return EXIT_FAILURE;
+                }
+                opt_cnt++;
+        } /* while (there are options) */
 
-                if (opt_char == 1)
-                        opt_char = 'f';
-                for (l = limits_tbl; l != &limits_tbl[ARRAY_SIZE(limits_tbl)]; l++) {
-                        if (opt_char == l->option) {
-                                char *val_str;
-
-                                getrlimit(l->cmd, &limit);
-
-                                val_str = optarg;
-                                if (!val_str && argv[optind] && argv[optind][0] != '-')
-                                        val_str = argv[optind++]; /* ++ skips NN in "-c NN" case */
-                                if (val_str) {
-                                        rlim_t val;
-
-                                        if (strcmp(val_str, "unlimited") == 0)
-                                                val = RLIM_INFINITY;
-                                        else {
-                                                if (sizeof(val) == sizeof(int))
-                                                        val = bb_strtou(val_str, NULL, 10);
-                                                else if (sizeof(val) == sizeof(long))
-                                                        val = bb_strtoul(val_str, NULL, 10);
-                                                else
-                                                        val = bb_strtoull(val_str, NULL, 10);
-                                                if (errno) {
-                                                        bb_error_msg("invalid number '%s'", val_str);
-                                                        return EXIT_FAILURE;
-                                                }
-                                                val <<= l->factor_shift;
-                                        }
-//bb_error_msg("opt %c val_str:'%s' val:%lld", opt_char, val_str, (long long)val);
-                                        /* from man bash: "If neither -H nor -S
-                                         * is specified, both the soft and hard
-                                         * limits are set. */
-                                        if (!opts)
-                                                opts = OPT_hard + OPT_soft;
-                                        if (opts & OPT_hard)
-                                                limit.rlim_max = val;
-                                        if (opts & OPT_soft)
-                                                limit.rlim_cur = val;
-//bb_error_msg("setrlimit(%d, %lld, %lld)", l->cmd, (long long)limit.rlim_cur, (long long)limit.rlim_max);
-                                        if (setrlimit(l->cmd, &limit) < 0) {
-                                                bb_perror_msg("error setting limit");
-                                                return EXIT_FAILURE;
-                                        }
-                                } else {
-                                        printlim(opts, &limit, l);
-                                }
-                                break;
-                        }
-                } /* for (every possible opt) */
+        if (!(opts & (OPT_hard | OPT_soft)))
+                opts |= (OPT_hard | OPT_soft);
+        if (opts & OPT_all) {
+                for (i = 0; i < ARRAY_SIZE(limits_tbl); i++) {
+                        getrlimit(limits_tbl[i].cmd, &limit);
+                        printf("-%c: %-30s ", limit_chars[i], limits_tbl[i].name);
+                        printlim(opts, &limit, &limits_tbl[i]);
+                }
+                return EXIT_SUCCESS;
+        }
 
-                if (l == &limits_tbl[ARRAY_SIZE(limits_tbl)]) {
-                        /* bad option. getopt already complained. */
+        /* Second pass: set or print limits, in order */
+        GETOPT_RESET();
+        while (1) {
+                char *val_str;
+                int opt_char = getopt(argc, argv, ulimit_opt_string);
+
+                if (opt_char == -1)
                         break;
+                if (opt_char == 'H')
+                        continue;
+                if (opt_char == 'S')
+                        continue;
+                //if (opt_char == 'a') - impossible
+
+                i = 0; /* if "ulimit NNN", -f is assumed */
+                if (opt_char != 1) {
+                        i = strchrnul(limit_chars, opt_char) - limit_chars;
+                        //if (i >= ARRAY_SIZE(limits_tbl)) - bad option, impossible
+                }
+
+                val_str = optarg;
+                if (!val_str && argv[optind] && argv[optind][0] != '-')
+                        val_str = argv[optind++]; /* ++ skips NN in "-c NN" case */
+
+                getrlimit(limits_tbl[i].cmd, &limit);
+                if (!val_str) {
+                        if (opt_cnt > 1)
+                                printf("-%c: %-30s ", limit_chars[i], limits_tbl[i].name);
+                        printlim(opts, &limit, &limits_tbl[i]);
+                } else {
+                        rlim_t val = RLIM_INFINITY;
+                        if (strcmp(val_str, "unlimited") != 0) {
+                                if (sizeof(val) == sizeof(int))
+                                        val = bb_strtou(val_str, NULL, 10);
+                                else if (sizeof(val) == sizeof(long))
+                                        val = bb_strtoul(val_str, NULL, 10);
+                                else
+                                        val = bb_strtoull(val_str, NULL, 10);
+                                if (errno) {
+                                        bb_error_msg("invalid number '%s'", val_str);
+                                        return EXIT_FAILURE;
+                                }
+                                val <<= limits_tbl[i].factor_shift;
+                        }
+//bb_error_msg("opt %c val_str:'%s' val:%lld", opt_char, val_str, (long long)val);
+                        /* from man bash: "If neither -H nor -S
+                         * is specified, both the soft and hard
+                         * limits are set. */
+                        if (opts & OPT_hard)
+                                limit.rlim_max = val;
+                        if (opts & OPT_soft)
+                                limit.rlim_cur = val;
+//bb_error_msg("setrlimit(%d, %lld, %lld)", limits_tbl[i].cmd, (long long)limit.rlim_cur, (long long)limit.rlim_max);
+                        if (setrlimit(limits_tbl[i].cmd, &limit) < 0) {
+                                bb_perror_msg("error setting limit");
+                                return EXIT_FAILURE;
+                        }
                 }
         } /* while (there are options) */
 
-        return 0;
+        if (opt_cnt == 0) {
+                /* "bare ulimit": treat it as if it was -f */
+                getrlimit(limits_tbl[0].cmd, &limit);
+                printlim(opts, &limit, &limits_tbl[0]);
+        }
+
+        return EXIT_SUCCESS;
 }