iproute2: clearer error messages for fifo and tbf qdiscs

Clearer error messages for fifo and tbf qdiscs:
- Say who is complaining
- Don't just say a parameter is bad, show the offending parameter
- Be clearer about duplicate parameters vs illegal pairs of parameters
- Try to give multiple error messages rather than let the user discover the errors one by one
- When there are parameter aliases, try to use the variant that was used, or at least mention them all

Note that in the old version an empty parameter list to tbf would just cause an explain() message
without a specific error message. By simply removing the relevant error check, the code now
handles this error more gracefully by printing an error message for all mandatory parameters.
It still prints the explain() message.

Signed-off-by: Kees van Reeuwijk <reeuwijk@few.vu.nl>

diff --git a/tc/q_fifo.c b/tc/q_fifo.c
index 6242a98b76259b54f1d7891aa0bbaf8441e6caca..c9ab123f0b5d50661e71d33f1786b4729abf45a8 100644 (file)
--- a/tc/q_fifo.c
+++ b/tc/q_fifo.c
@@ -38,7 +38,7 @@ static int fifo_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct n
                if (strcmp(*argv, "limit") == 0) {
                        NEXT_ARG();
                        if (get_size(&opt.limit, *argv)) {
-                               fprintf(stderr, "Illegal \"limit\"\n");
+                               fprintf(stderr, "%s: Illegal value for \"limit\": \"%s\"\n", qu->id, *argv);
                                return -1;
                        }
                        ok++;
@@ -46,7 +46,7 @@ static int fifo_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct n
                        explain();
                        return -1;
                } else {
-                       fprintf(stderr, "What is \"%s\"?\n", *argv);
+                       fprintf(stderr, "%s: unknown parameter \"%s\"\n", qu->id, *argv);
                        explain();
                        return -1;
                }

diff --git a/tc/q_tbf.c b/tc/q_tbf.c
index dc556fe01d745fe808d0db0fe192dae5a9beb609..72cfff669faa4b4a387d296c2f23be42e1bc5b96 100644 (file)
--- a/tc/q_tbf.c
+++ b/tc/q_tbf.c
@@ -30,9 +30,9 @@ static void explain(void)
        fprintf(stderr, "[ overhead BYTES ] [ linklayer TYPE ]\n");
 }
 
-static void explain1(char *arg)
+static void explain1(const char *arg, const char *val)
 {
-       fprintf(stderr, "Illegal \"%s\"\n", arg);
+       fprintf(stderr, "tbf: illegal value for \"%s\": \"%s\"\n", arg, val);
 }
 
 
@@ -53,130 +53,150 @@ static int tbf_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nl
        while (argc > 0) {
                if (matches(*argv, "limit") == 0) {
                        NEXT_ARG();
-                       if (opt.limit || latency) {
-                               fprintf(stderr, "Double \"limit/latency\" spec\n");
+                       if (opt.limit) {
+                               fprintf(stderr, "tbf: duplicate \"limit\" specification\n");
+                               return -1;
+                       }
+                       if (latency) {
+                               fprintf(stderr, "tbf: specifying both \"latency\" and \"limit\" is not allowed\n");
                                return -1;
                        }
                        if (get_size(&opt.limit, *argv)) {
-                               explain1("limit");
+                               explain1("limit", *argv);
                                return -1;
                        }
                        ok++;
                } else if (matches(*argv, "latency") == 0) {
                        NEXT_ARG();
-                       if (opt.limit || latency) {
-                               fprintf(stderr, "Double \"limit/latency\" spec\n");
+                       if (latency) {
+                               fprintf(stderr, "tbf: duplicate \"latency\" specification\n");
+                               return -1;
+                       }
+                       if (opt.limit) {
+                               fprintf(stderr, "tbf: specifying both \"limit\" and \"/latency\" is not allowed\n");
                                return -1;
                        }
                        if (get_time(&latency, *argv)) {
-                               explain1("latency");
+                               explain1("latency", *argv);
                                return -1;
                        }
                        ok++;
                } else if (matches(*argv, "burst") == 0 ||
                        strcmp(*argv, "buffer") == 0 ||
                        strcmp(*argv, "maxburst") == 0) {
+                       const char *parm_name = *argv;
                        NEXT_ARG();
                        if (buffer) {
-                               fprintf(stderr, "Double \"buffer/burst\" spec\n");
+                               fprintf(stderr, "tbf: duplicate \"buffer/burst/maxburst\" specification\n");
                                return -1;
                        }
                        if (get_size_and_cell(&buffer, &Rcell_log, *argv) < 0) {
-                               explain1("buffer");
+                               explain1(parm_name, *argv);
                                return -1;
                        }
                        ok++;
                } else if (strcmp(*argv, "mtu") == 0 ||
                           strcmp(*argv, "minburst") == 0) {
+                       const char *parm_name = *argv;
                        NEXT_ARG();
                        if (mtu) {
-                               fprintf(stderr, "Double \"mtu/minburst\" spec\n");
+                               fprintf(stderr, "tbf: duplicate \"mtu/minburst\" specification\n");
                                return -1;
                        }
                        if (get_size_and_cell(&mtu, &Pcell_log, *argv) < 0) {
-                               explain1("mtu");
+                               explain1(parm_name, *argv);
                                return -1;
                        }
                        ok++;
                } else if (strcmp(*argv, "mpu") == 0) {
                        NEXT_ARG();
                        if (mpu) {
-                               fprintf(stderr, "Double \"mpu\" spec\n");
+                               fprintf(stderr, "tbf: duplicate \"mpu\" specification\n");
                                return -1;
                        }
                        if (get_size(&mpu, *argv)) {
-                               explain1("mpu");
+                               explain1("mpu", *argv);
                                return -1;
                        }
                        ok++;
                } else if (strcmp(*argv, "rate") == 0) {
                        NEXT_ARG();
                        if (opt.rate.rate) {
-                               fprintf(stderr, "Double \"rate\" spec\n");
+                               fprintf(stderr, "tbf: duplicate \"rate\" specification\n");
                                return -1;
                        }
                        if (get_rate(&opt.rate.rate, *argv)) {
-                               explain1("rate");
+                               explain1("rate", *argv);
                                return -1;
                        }
                        ok++;
                } else if (matches(*argv, "peakrate") == 0) {
                        NEXT_ARG();
                        if (opt.peakrate.rate) {
-                               fprintf(stderr, "Double \"peakrate\" spec\n");
+                               fprintf(stderr, "tbf: duplicate \"peakrate\" specification\n");
                                return -1;
                        }
                        if (get_rate(&opt.peakrate.rate, *argv)) {
-                               explain1("peakrate");
+                               explain1("peakrate", *argv);
                                return -1;
                        }
                        ok++;
                } else if (matches(*argv, "overhead") == 0) {
                        NEXT_ARG();
                        if (overhead) {
-                               fprintf(stderr, "Double \"overhead\" spec\n");
+                               fprintf(stderr, "tbf: duplicate \"overhead\" specification\n");
                                return -1;
                        }
                        if (get_u16(&overhead, *argv, 10)) {
-                               explain1("overhead"); return -1;
+                               explain1("overhead", *argv); return -1;
                        }
                } else if (matches(*argv, "linklayer") == 0) {
                        NEXT_ARG();
                        if (get_linklayer(&linklayer, *argv)) {
-                               explain1("linklayer"); return -1;
+                               explain1("linklayer", *argv); return -1;
                        }
                } else if (strcmp(*argv, "help") == 0) {
                        explain();
                        return -1;
                } else {
-                       fprintf(stderr, "What is \"%s\"?\n", *argv);
+                       fprintf(stderr, "tbf: unknown parameter \"%s\"\n", *argv);
                        explain();
                        return -1;
                }
                argc--; argv++;
        }
 
-       if (!ok) {
-               explain();
-               return -1;
-       }
+        int verdict = 0;
 
-       if (opt.rate.rate == 0 || !buffer) {
-               fprintf(stderr, "Both \"rate\" and \"burst\" are required.\n");
-               return -1;
+        /* Be nice to the user: try to emit all error messages in
+         * one go rather than reveal one more problem when a
+         * previous one has been fixed.
+         */
+       if (opt.rate.rate == 0) {
+               fprintf(stderr, "tbf: the \"rate\" parameter is mandatory.\n");
+               verdict = -1;
+       }
+       if (!buffer) {
+               fprintf(stderr, "tbf: the \"burst\" parameter is mandatory.\n");
+               verdict = -1;
        }
        if (opt.peakrate.rate) {
                if (!mtu) {
-                       fprintf(stderr, "\"mtu\" is required, if \"peakrate\" is requested.\n");
-                       return -1;
+                       fprintf(stderr, "tbf: when \"peakrate\" is specified, \"mtu\" must also be specified.\n");
+                       verdict = -1;
                }
        }
 
        if (opt.limit == 0 && latency == 0) {
-               fprintf(stderr, "Either \"limit\" or \"latency\" are required.\n");
-               return -1;
+               fprintf(stderr, "tbf: either \"limit\" or \"latency\" is required.\n");
+               verdict = -1;
        }
 
+        if (verdict != 0) {
+                explain();
+                return verdict;
+        }
+
        if (opt.limit == 0) {
                double lim = opt.rate.rate*(double)latency/TIME_UNITS_PER_SEC + buffer;
                if (opt.peakrate.rate) {
@@ -190,7 +210,7 @@ static int tbf_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nl
        opt.rate.mpu      = mpu;
        opt.rate.overhead = overhead;
        if (tc_calc_rtable(&opt.rate, rtab, Rcell_log, mtu, linklayer) < 0) {
-               fprintf(stderr, "TBF: failed to calculate rate table.\n");
+               fprintf(stderr, "tbf: failed to calculate rate table.\n");
                return -1;
        }
        opt.buffer = tc_calc_xmittime(opt.rate.rate, buffer);
@@ -199,7 +219,7 @@ static int tbf_parse_opt(struct qdisc_util *qu, int argc, char **argv, struct nl
                opt.peakrate.mpu      = mpu;
                opt.peakrate.overhead = overhead;
                if (tc_calc_rtable(&opt.peakrate, ptab, Pcell_log, mtu, linklayer) < 0) {
-                       fprintf(stderr, "TBF: failed to calculate peak rate table.\n");
+                       fprintf(stderr, "tbf: failed to calculate peak rate table.\n");
                        return -1;
                }
                opt.mtu = tc_calc_xmittime(opt.peakrate.rate, mtu);