seccomp: parse_config_v2()

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/seccomp.c b/src/lxc/seccomp.c
index cc9212d78824b293ab7295ba910d48226736f326..c774aa2ecdb32fa69241a1ef66eb881a91201219 100644 (file)
--- a/src/lxc/seccomp.c
+++ b/src/lxc/seccomp.c
@@ -549,12 +549,13 @@ bool do_resolve_add_rule(uint32_t arch, char *line, scmp_filter_ctx ctx,
  */
 static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
 {
-       char *p;
        int ret;
+       char *p;
+       enum lxc_hostarch_t cur_rule_arch, native_arch;
+       size_t line_bufsz = 0;
        bool blacklist = false;
+       char *rule_line = NULL;
        uint32_t default_policy_action = -1, default_rule_action = -1;
-       enum lxc_hostarch_t native_arch = get_hostarch(),
-                           cur_rule_arch = native_arch;
        struct seccomp_v2_rule rule;
        struct scmp_ctx_info {
                uint32_t architectures[3];
@@ -565,11 +566,12 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
        if (strncmp(line, "blacklist", 9) == 0)
                blacklist = true;
        else if (strncmp(line, "whitelist", 9) != 0) {
-               ERROR("Bad seccomp policy style: %s", line);
+               ERROR("Bad seccomp policy style \"%s\"", line);
                return -1;
        }
 
-       if ((p = strchr(line, ' '))) {
+       p = strchr(line, ' ');
+       if (p) {
                default_policy_action = get_v2_default_action(p + 1);
                if (default_policy_action == -2)
                        return -1;
@@ -579,11 +581,13 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
        if (blacklist) {
                if (default_policy_action == -1)
                        default_policy_action = SCMP_ACT_ALLOW;
+
                if (default_rule_action == -1)
                        default_rule_action = SCMP_ACT_KILL;
        } else {
                if (default_policy_action == -1)
                        default_policy_action = SCMP_ACT_KILL;
+
                if (default_rule_action == -1)
                        default_rule_action = SCMP_ACT_ALLOW;
        }
@@ -592,6 +596,8 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
        ctx.architectures[0] = SCMP_ARCH_NATIVE;
        ctx.architectures[1] = SCMP_ARCH_NATIVE;
        ctx.architectures[2] = SCMP_ARCH_NATIVE;
+       native_arch = get_hostarch();
+       cur_rule_arch = native_arch;
        if (native_arch == lxc_seccomp_arch_amd64) {
                cur_rule_arch = lxc_seccomp_arch_all;
 
@@ -638,17 +644,17 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                cur_rule_arch = lxc_seccomp_arch_all;
 
                ctx.architectures[0] = SCMP_ARCH_ARM;
-               ctx.contexts[0] =
-                   get_new_ctx(lxc_seccomp_arch_arm, default_policy_action,
-                               &ctx.needs_merge[0]);
+               ctx.contexts[0] = get_new_ctx(lxc_seccomp_arch_arm,
+                                             default_policy_action,
+                                             &ctx.needs_merge[0]);
                if (!ctx.contexts[0])
                        goto bad;
 
 #ifdef SCMP_ARCH_AARCH64
                ctx.architectures[2] = SCMP_ARCH_AARCH64;
-               ctx.contexts[2] =
-                   get_new_ctx(lxc_seccomp_arch_arm64, default_policy_action,
-                               &ctx.needs_merge[2]);
+               ctx.contexts[2] = get_new_ctx(lxc_seccomp_arch_arm64,
+                                             default_policy_action,
+                                             &ctx.needs_merge[2]);
                if (!ctx.contexts[2])
                        goto bad;
 #endif
@@ -709,25 +715,30 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                        ERROR("Error re-initializing Seccomp");
                        return -1;
                }
-               if (seccomp_attr_set(conf->seccomp_ctx, SCMP_FLTATR_CTL_NNP, 0)) {
-                       ERROR("Failed to turn off no-new-privs");
+
+               ret = seccomp_attr_set(conf->seccomp_ctx, SCMP_FLTATR_CTL_NNP, 0);
+               if (ret < 0) {
+                       ERROR("%s - Failed to turn off no-new-privs", strerror(-ret));
                        return -1;
                }
+
 #ifdef SCMP_FLTATR_ATL_TSKIP
-               if (seccomp_attr_set(conf->seccomp_ctx, SCMP_FLTATR_ATL_TSKIP, 1)) {
-                       WARN("Failed to turn on seccomp nop-skip, continuing");
-               }
+               ret = seccomp_attr_set(conf->seccomp_ctx, SCMP_FLTATR_ATL_TSKIP, 1);
+               if (ret < 0)
+                       WARN("%s - Failed to turn on seccomp nop-skip, continuing", strerror(-ret));
 #endif
        }
 
-       while (fgets(line, 1024, f)) {
-
+       while (getline(&rule_line, &line_bufsz, f) != -1) {
                if (line[0] == '#')
                        continue;
-               if (strlen(line) == 0)
+
+               if (line[0] == '\0')
                        continue;
+
                remove_trailing_newlines(line);
-               INFO("processing: .%s", line);
+
+               INFO("Processing \"%s\"", line);
                if (line[0] == '[') {
                        /* Read the architecture for next set of rules. */
                        if (strcmp(line, "[x86]") == 0 ||
@@ -737,6 +748,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_i386;
                        } else if (strcmp(line, "[x32]") == 0 ||
                                   strcmp(line, "[X32]") == 0) {
@@ -744,6 +756,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_x32;
                        } else if (strcmp(line, "[X86_64]") == 0 ||
                                   strcmp(line, "[x86_64]") == 0) {
@@ -751,6 +764,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_amd64;
                        } else if (strcmp(line, "[all]") == 0 ||
                                   strcmp(line, "[ALL]") == 0) {
@@ -764,6 +778,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_arm;
                        }
 #endif
@@ -774,6 +789,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_arm64;
                        }
 #endif
@@ -784,6 +800,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_ppc64le;
                        }
 #endif
@@ -794,6 +811,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_ppc64;
                        }
 #endif
@@ -805,6 +823,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_ppc;
                        }
 #endif
@@ -815,6 +834,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_mips64;
                        } else if (strcmp(line, "[mips64n32]") == 0 ||
                                   strcmp(line, "[MIPS64N32]") == 0) {
@@ -822,6 +842,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_mips64n32;
                        } else if (strcmp(line, "[mips]") == 0 ||
                                   strcmp(line, "[MIPS]") == 0) {
@@ -830,6 +851,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_mips;
                        } else if (strcmp(line, "[mipsel64]") == 0 ||
                                   strcmp(line, "[MIPSEL64]") == 0) {
@@ -837,6 +859,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_mipsel64;
                        } else if (strcmp(line, "[mipsel64n32]") == 0 ||
                                   strcmp(line, "[MIPSEL64N32]") == 0) {
@@ -844,6 +867,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_mipsel64n32;
                        } else if (strcmp(line, "[mipsel]") == 0 ||
                                   strcmp(line, "[MIPSEL]") == 0) {
@@ -852,6 +876,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_mipsel;
                        }
 #endif
@@ -862,11 +887,12 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                        cur_rule_arch = lxc_seccomp_arch_unknown;
                                        continue;
                                }
+
                                cur_rule_arch = lxc_seccomp_arch_s390x;
-                       }
 #endif
-                       else
+                       } else {
                                goto bad_arch;
+                       }
 
                        continue;
                }
@@ -886,6 +912,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                if (!do_resolve_add_rule(SCMP_ARCH_NATIVE, line,
                                         conf->seccomp_ctx, &rule))
                        goto bad_rule;
+
                INFO("Added native rule for arch %d for %s action %d(%s)",
                     SCMP_ARCH_NATIVE, line, rule.action,
                     get_action_name(rule.action));
@@ -894,6 +921,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                        if (!do_resolve_add_rule(ctx.architectures[0], line,
                                                 ctx.contexts[0], &rule))
                                goto bad_rule;
+
                        INFO("Added compat rule for arch %d for %s action %d(%s)",
                             ctx.architectures[0], line, rule.action,
                             get_action_name(rule.action));
@@ -903,6 +931,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                        if (!do_resolve_add_rule(ctx.architectures[1], line,
                                                 ctx.contexts[1], &rule))
                                goto bad_rule;
+
                        INFO("Added compat rule for arch %d for %s action %d(%s)",
                             ctx.architectures[1], line, rule.action,
                             get_action_name(rule.action));
@@ -912,6 +941,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                        if (!do_resolve_add_rule(ctx.architectures[2], line,
                                                ctx.contexts[2], &rule))
                                goto bad_rule;
+
                        INFO("Added native rule for arch %d for %s action %d(%s)",
                             ctx.architectures[2], line, rule.action,
                             get_action_name(rule.action));
@@ -927,6 +957,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                      "context into main context");
                                goto bad;
                        }
+
                        TRACE("Merged first compat seccomp context into main context");
                } else {
                        seccomp_release(ctx.contexts[0]);
@@ -942,6 +973,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                      "context into main context");
                                goto bad;
                        }
+
                        TRACE("Merged second compat seccomp context into main context");
                } else {
                        seccomp_release(ctx.contexts[1]);
@@ -957,6 +989,7 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                                      "context into main context");
                                goto bad;
                        }
+
                        TRACE("Merged third compat seccomp context into main context");
                } else {
                        seccomp_release(ctx.contexts[2]);
@@ -964,19 +997,25 @@ static int parse_config_v2(FILE *f, char *line, struct lxc_conf *conf)
                }
        }
 
+       free(rule_line);
        return 0;
 
 bad_arch:
-       ERROR("Unsupported arch: %s.", line);
+       ERROR("Unsupported architecture \"%s\"", line);
+
 bad_rule:
 bad:
        if (ctx.contexts[0])
                seccomp_release(ctx.contexts[0]);
+
        if (ctx.contexts[1])
                seccomp_release(ctx.contexts[1]);
+
        if (ctx.contexts[2])
                seccomp_release(ctx.contexts[2]);
 
+       free(rule_line);
+
        return -1;
 }
 #else /* HAVE_DECL_SECCOMP_SYSCALL_RESOLVE_NAME_ARCH */