tools: bpf_dbg: various misc code cleanups

Lets clean up bpf_dbg a bit and improve its code slightly
in various areas: i) Get rid of some macros as there's no
good reason for keeping them, ii) remove one unused variable
and reduce scope of various variables found by cppcheck,
iii) Close non-default file descriptors when exiting the shell.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/tools/net/bpf_dbg.c b/tools/net/bpf_dbg.c
index 65dc757f7f7b5c8d41bf49d95fe47df6b549c4fc..bb31813e43ddca8bd2bad4544e593d8c6df418f2 100644 (file)
--- a/tools/net/bpf_dbg.c
+++ b/tools/net/bpf_dbg.c
@@ -87,9 +87,6 @@
        __attribute__ ((format (printf, (pos_fmtstr), (pos_fmtargs))))
 #endif
 
-#define CMD(_name, _func) { .name = _name, .func = _func, }
-#define OP(_op, _name)      [_op] = _name
-
 enum {
        CMD_OK,
        CMD_ERR,
@@ -145,32 +142,32 @@ static size_t pcap_map_size = 0;
 static char *pcap_ptr_va_start, *pcap_ptr_va_curr;
 
 static const char * const op_table[] = {
-       OP(BPF_ST, "st"),
-       OP(BPF_STX, "stx"),
-       OP(BPF_LD_B, "ldb"),
-       OP(BPF_LD_H, "ldh"),
-       OP(BPF_LD_W, "ld"),
-       OP(BPF_LDX, "ldx"),
-       OP(BPF_LDX_B, "ldxb"),
-       OP(BPF_JMP_JA, "ja"),
-       OP(BPF_JMP_JEQ, "jeq"),
-       OP(BPF_JMP_JGT, "jgt"),
-       OP(BPF_JMP_JGE, "jge"),
-       OP(BPF_JMP_JSET, "jset"),
-       OP(BPF_ALU_ADD, "add"),
-       OP(BPF_ALU_SUB, "sub"),
-       OP(BPF_ALU_MUL, "mul"),
-       OP(BPF_ALU_DIV, "div"),
-       OP(BPF_ALU_MOD, "mod"),
-       OP(BPF_ALU_NEG, "neg"),
-       OP(BPF_ALU_AND, "and"),
-       OP(BPF_ALU_OR, "or"),
-       OP(BPF_ALU_XOR, "xor"),
-       OP(BPF_ALU_LSH, "lsh"),
-       OP(BPF_ALU_RSH, "rsh"),
-       OP(BPF_MISC_TAX, "tax"),
-       OP(BPF_MISC_TXA, "txa"),
-       OP(BPF_RET, "ret"),
+       [BPF_ST]        = "st",
+       [BPF_STX]       = "stx",
+       [BPF_LD_B]      = "ldb",
+       [BPF_LD_H]      = "ldh",
+       [BPF_LD_W]      = "ld",
+       [BPF_LDX]       = "ldx",
+       [BPF_LDX_B]     = "ldxb",
+       [BPF_JMP_JA]    = "ja",
+       [BPF_JMP_JEQ]   = "jeq",
+       [BPF_JMP_JGT]   = "jgt",
+       [BPF_JMP_JGE]   = "jge",
+       [BPF_JMP_JSET]  = "jset",
+       [BPF_ALU_ADD]   = "add",
+       [BPF_ALU_SUB]   = "sub",
+       [BPF_ALU_MUL]   = "mul",
+       [BPF_ALU_DIV]   = "div",
+       [BPF_ALU_MOD]   = "mod",
+       [BPF_ALU_NEG]   = "neg",
+       [BPF_ALU_AND]   = "and",
+       [BPF_ALU_OR]    = "or",
+       [BPF_ALU_XOR]   = "xor",
+       [BPF_ALU_LSH]   = "lsh",
+       [BPF_ALU_RSH]   = "rsh",
+       [BPF_MISC_TAX]  = "tax",
+       [BPF_MISC_TXA]  = "txa",
+       [BPF_RET]       = "ret",
 };
 
 static __check_format_printf(1, 2) int rl_printf(const char *fmt, ...)
@@ -1127,7 +1124,6 @@ static int cmd_step(char *num)
 static int cmd_select(char *num)
 {
        unsigned int which, i;
-       struct pcap_pkthdr *hdr;
        bool have_next = true;
 
        if (!pcap_loaded() || strlen(num) == 0)
@@ -1144,7 +1140,7 @@ static int cmd_select(char *num)
 
        for (i = 0; i < which && (have_next = pcap_next_pkt()); i++)
                /* noop */;
-       if (!have_next || (hdr = pcap_curr_pkt()) == NULL) {
+       if (!have_next || pcap_curr_pkt() == NULL) {
                rl_printf("no packet #%u available!\n", which);
                pcap_reset_pkt();
                return CMD_ERR;
@@ -1177,9 +1173,8 @@ static int cmd_breakpoint(char *subcmd)
 static int cmd_run(char *num)
 {
        static uint32_t pass = 0, fail = 0;
-       struct pcap_pkthdr *hdr;
        bool has_limit = true;
-       int ret, pkts = 0, i = 0;
+       int pkts = 0, i = 0;
 
        if (!bpf_prog_loaded() || !pcap_loaded())
                return CMD_ERR;
@@ -1189,10 +1184,10 @@ static int cmd_run(char *num)
                has_limit = false;
 
        do {
-               hdr = pcap_curr_pkt();
-               ret = bpf_run_all(bpf_image, bpf_prog_len,
-                                 (uint8_t *) hdr + sizeof(*hdr),
-                                 hdr->caplen, hdr->len);
+               struct pcap_pkthdr *hdr = pcap_curr_pkt();
+               int ret = bpf_run_all(bpf_image, bpf_prog_len,
+                                     (uint8_t *) hdr + sizeof(*hdr),
+                                     hdr->caplen, hdr->len);
                if (ret > 0)
                        pass++;
                else if (ret == 0)
@@ -1245,14 +1240,14 @@ static int cmd_quit(char *dontcare)
 }
 
 static const struct shell_cmd cmds[] = {
-       CMD("load",             cmd_load),
-       CMD("select",           cmd_select),
-       CMD("step",             cmd_step),
-       CMD("run",              cmd_run),
-       CMD("breakpoint",       cmd_breakpoint),
-       CMD("disassemble",      cmd_disassemble),
-       CMD("dump",             cmd_dump),
-       CMD("quit",             cmd_quit),
+       { .name = "load", .func = cmd_load },
+       { .name = "select", .func = cmd_select },
+       { .name = "step", .func = cmd_step },
+       { .name = "run", .func = cmd_run },
+       { .name = "breakpoint", .func = cmd_breakpoint },
+       { .name = "disassemble", .func = cmd_disassemble },
+       { .name = "dump", .func = cmd_dump },
+       { .name = "quit", .func = cmd_quit },
 };
 
 static int execf(char *arg)
@@ -1280,7 +1275,6 @@ out:
 static char *shell_comp_gen(const char *buf, int state)
 {
        static int list_index, len;
-       const char *name;
 
        if (!state) {
                list_index = 0;
@@ -1288,9 +1282,9 @@ static char *shell_comp_gen(const char *buf, int state)
        }
 
        for (; list_index < array_size(cmds); ) {
-               name = cmds[list_index].name;
-               list_index++;
+               const char *name = cmds[list_index].name;
 
+               list_index++;
                if (strncmp(name, buf, len) == 0)
                        return strdup(name);
        }
@@ -1322,16 +1316,9 @@ static void init_shell(FILE *fin, FILE *fout)
 {
        char file[128];
 
-       memset(file, 0, sizeof(file));
-       snprintf(file, sizeof(file) - 1,
-                "%s/.bpf_dbg_history", getenv("HOME"));
-
+       snprintf(file, sizeof(file), "%s/.bpf_dbg_history", getenv("HOME"));
        read_history(file);
 
-       memset(file, 0, sizeof(file));
-       snprintf(file, sizeof(file) - 1,
-                "%s/.bpf_dbg_init", getenv("HOME"));
-
        rl_instream = fin;
        rl_outstream = fout;
 
@@ -1348,37 +1335,41 @@ static void init_shell(FILE *fin, FILE *fout)
        rl_bind_key_in_map('\t', rl_complete, emacs_meta_keymap);
        rl_bind_key_in_map('\033', rl_complete, emacs_meta_keymap);
 
+       snprintf(file, sizeof(file), "%s/.bpf_dbg_init", getenv("HOME"));
        rl_read_init_file(file);
+
        rl_prep_terminal(0);
        rl_set_signals();
 
        signal(SIGINT, intr_shell);
 }
 
-static void exit_shell(void)
+static void exit_shell(FILE *fin, FILE *fout)
 {
        char file[128];
 
-       memset(file, 0, sizeof(file));
-       snprintf(file, sizeof(file) - 1,
-                "%s/.bpf_dbg_history", getenv("HOME"));
-
+       snprintf(file, sizeof(file), "%s/.bpf_dbg_history", getenv("HOME"));
        write_history(file);
+
        clear_history();
        rl_deprep_terminal();
 
        try_close_pcap();
+
+       if (fin != stdin)
+               fclose(fin);
+       if (fout != stdout)
+               fclose(fout);
 }
 
 static int run_shell_loop(FILE *fin, FILE *fout)
 {
        char *buf;
-       int ret;
 
        init_shell(fin, fout);
 
        while ((buf = readline("> ")) != NULL) {
-               ret = execf(buf);
+               int ret = execf(buf);
                if (ret == CMD_EX)
                        break;
                if (ret == CMD_OK && strlen(buf) > 0)
@@ -1387,7 +1378,7 @@ static int run_shell_loop(FILE *fin, FILE *fout)
                free(buf);
        }
 
-       exit_shell();
+       exit_shell(fin, fout);
        return 0;
 }